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| PPAR Res. 2009; 2009: 373524. Published online 2008 December 1. doi: 10.1155/2009/373524. | PMCID: PMC2593088 |
The Effects of Thiazolidinediones on Metabolic Complications and Lipodystrophy in HIV-Infected Patients Jussi Sutinen* Division of Infectious Diseases and Division of Diabetes, Department of Medicine, Helsinki University Central Hospital, 00029 HUS, Helsinki, Finland Received March 18, 2008; Accepted August 25, 2008. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
Abstract Highly active antiretroviral therapy (HAART)-associated metabolic complications include lipoatrophy (loss of subcutaneous adipose tissue (SAT)) and insulin resistance. Thiazolidinediones are insulin-sensitizing antidiabetic agents which—as an untoward side effect in obese diabetic patients—increase SAT. Furthermore, troglitazone has improved lipoatrophy and glycemic control in non-HIV patients with various forms of lipodystrophy. These data have led to 14 clinical trials to examine whether thiazolidinediones could be useful in the treatment of HAART-associated metabolic complications. The results of these studies indicate very modest, if any, effect on lipoatrophic SAT, probably due to ongoing HAART negating the beneficial effect. The benefit might be more prominent in patients not taking thymidine analoges. Despite the poor effect on lipoatrophy, thiazolidin-ediones improved insulin sensitivity. However, especially rosiglitazone induced harmful effects on blood lipids. Current data do not provide evidence for the use of thiazolidinediones in the treatment of HAART-associated lipoatrophy, but treatment of lipoatrophy-associated diabetes may be warranted. The role of thiazolidinediones for novel indications, such as hepatosteatosis, should be studied in these patients. |
The prognosis of HIV-infection has
drastically changed after the introduction of combination antiretroviral
therapy [ 1] often referred to as highly active antiretroviral therapy (HAART). Since the eradication of the virus is
impossible with current medicines [ 2] and since periodic treatment with
HAART can be harmful when compared to continuous therapy [ 3], patients need to continue therapy uninterruptedly
and permanently. Lifelong exposure to HAART puts patients
at a significant risk for long-term metabolic adverse effects including lipodystrophy,
insulin resistance, hyperlipidemia, and increased cardiovascular morbidity [ 4, 5]. The most characteristic component
of HAART-associated lipodystrophy is the loss of subcutaneous adipose tissue [ 6] which has proven to be very difficult
to treat ( Figure 1).  | Figure 1Abdominal magnetic resonance image (MRI) of a HAART-treated patient with normal fat distribution (a) and a patient with severe HAART-associated lipodystrophy with complete loss of subcutaneous fat and accumulation of intra-abdominal fat (b). Fat is shown (more ...) |
Thiazolidinediones (glitazones) are
oral insulin-sensitizing antidiabetic agents. As an untoward side effect, glitazones
increase subcutaneous fat mass in
patients with type 2 diabetes [ 7– 9]. Additionally, in non-HIV infected
patients with various forms of lipodystrophy, troglitazone has improved metabolic
control and subcutaneous lipoatrophy [ 10]. These insulin-sensitizing and fat-inducing
effects of glitazones have lead to several clinical trials examining whether these
drugs could reverse lipoatrophy and
insulin resistance in patients with HAART-associated lipodystrophy. The ensuing review is focused on summarizing
the currently available clinical data on the use of glitazones in patients with
HAART-associated lipodystrophy |
Thiazolidinediones are synthetic ligands
for peroxisome proliferator-activated receptor gamma (PPAR γ). PPAR γ is a nuclear
receptor which alters expression of multiple genes including those regulating lipid
and glucose metabolism [ 11]. PPAR γ is expressed mainly in
adipose tissue and is also found
in pancreatic beta cells, vascular endothelium, and macrophages, and in low
quantities in other tissues such as the liver, skeletal muscle, and the heart [ 12, 13]. The activation of PPAR γ is critical
in adipocyte differentiation, fatty acid uptake, and storage in the adipocytes [ 14, 15]. Glitazone-induced activation of
PPAR γ in adipose tissue may improve the whole body insulin
sensitivity by keeping fatty acids within adipocytes and hence protecting other
tissues (liver, skeletal muscle, and pancreatic beta cells) from the “toxic”
effects of the high-circulating concentration of free fatty acids [ 12]. Alternatively or additionally,
glitazones may affect whole body insulin sensitivity by altering adipokine
release from adipose tissue [ 12]. The potential role of PPAR γ in the
pathogenesis of some human lipodystrophies has been demonstrated in recent
studies finding dominant negative and loss-of-function mutations to affect the
ligand-binding domain of PPAR γ in non-HIV patients with partial lipodystrophy,
hepatic steatosis, dyslipidemia, and insulin resistance [ 13]. Furthermore, trogilitazone was
shown to improve subcutaneous lipoatrophy in HIV-negative patients with various
forms of lipodystrophic/lipoatrophic syndromes [ 10]. Taken together, the available data
make glitazones an interesting therapy option for HAART-associated lipodystrophy. |
3. HAART-Associated Lipodystrophy The prevalence of HAART-associated
lipodystrophy has varied from as low as 2% [ 16] up to 83% [ 17] in HAART-treated patients. This
huge variation is explained by the lack of uniformly accepted definition of
lipodystrophy, and the variable combination and duration of HAART in different studies.
Estimates from large surveys indicate a prevalence of 50% of at least one
physical abnormality after 12–18 months of
therapy [ 18, 19]. Most of these prevalence data arise
from patients taking mainly the older and metabolically more toxic antiretroviral
regimens. Although there are accumulating data demonstrating a significantly decreased
risk for lipodystrophy in patients taking newer antiretroviral agents [ 20, 21], lipodystrophy still remains a
significant clinical problem. Lipoatrophy, that is, a decrease in
subcutaneous adipose tissue (SAT) mass, has mainly been attributed to the use
of nucleoside reverse transcriptase inhibitors (NRTIs) and thymidine analoges (tNRTI)
in particular [ 22– 25]. The tNRTIs stavudine and more
recently zidovudine gradually decrease SAT mass. Typically, SAT initially
increases during the first 4–8 months of
therapy, but thereafter, a 19% decrease in limb fat per year has been described
with stavudine and didanosine containing regimens as compared to a decrease of
1.7% per year with zidovudine and lamivudine [ 26]. Further evidence demonstrating the
deleterious effects of tNRTIs on SAT arises from the so called “switch” studies.
Replacing tNRTI by abacavir or tenofovir has in several studies lead to an increase
of 300–500 g of limb fat
during the first 6–12 months after
the switch [ 27– 29]. Although most data indicate a
major role of tNRTIs in the development of lipoatrophy, other drug classes may
be involved. Irrespective of the NRTI backbone, nelfinavir (a protease
inhibitor) was associated with more severe fat loss than efavirenz
(nonnucleoside reverse transcriptase inhibitor) [ 30], whereas in another study efavirenz
caused more fat loss than lopinavir/ritonavir (protease inhibitor) [ 31]. The less significant role of protease
inhibitors (PIs) for lipoatrophy is demonstrated in the switch studies. In contrast
to the beneficial effects of switching away from tNRTIs, the effects of switching away from PIs have
been disappointing regarding lipoatrophy [ 32]. The potential pathophysiological mechanisms
leading to lipoatrophy include NRTI-induced inhibition of mitochondrial (mt)
DNA polymerase gamma through several different mechanisms [ 33, 34]. This inhibition would lead to decreased
mtDNA content which consequently would result in depletion of proteins encoded
by mtDNA and dysfunctional mitochondria. Additionally, also genes encoded by
nuclear DNA are affected by NRTIs, and these drugs promote apoptosis in adipocyte
cell modes in vitro [ 35]. In keeping with these in vitro data, human studies have
shown decreased mtDNA content in adipose tissue of patients with
HAART-associated lipodystrophy when compared to HIV-negative subjects,
HIV-infected patients not taking HAART, or to HAART-treated patients without
lipodystrophy [ 36– 39]. However, studies in healthy
subjects have shown that a 2-week exposure to NRTIs leads to a decrease in
mtRNA and alters expression of several nuclear genes without a significant
change in the mtDNA content [ 40]. Various studies have shown
multiple alterations in gene expression in lipoatrophic adipose tissue such as
decreased expression of several transcription factors (PPAR γ, SREBP-1c (sterol
regulatory element-binding protein), PPAR δ, C/EBP α, and β
(CCAAT/enhancer-binding protein)) [ 41, 42]. Alterations have also been
described in the expression of several genes involved in lipogenesis, fatty
acid, and glucose metabolism, for example, the expressions of acyl coenzyme A synthase,
lipoprotein lipase, and glucose transport protein 4 are decreased in patients
with HAART-associated lipodystrophy [ 42]. Several markers of inflammation such
as interleukin 6 (IL-6), tumor necrosis factor alpha (TNF α), CD45, and CD68
have been shown to be increased in lipoatrophic adipose tissue [ 41– 44]. Of the adipokines, the expression of
adiponectin in adipose tissue and its circulating concentration have been shown
to be decreased in several studies [ 44– 47], whereas serum concentrations of
leptin have been either decreased [ 48, 49], unchanged [ 46, 50, 51], or increased [ 52] in lipoatrophic patients. In
addition to these findings implying severe adipose tissue dysfunction,
increased rate of apoptosis has also been described in the SAT of these patients
[ 43, 53]. Although multiple alterations have
been described in lipoatrophic adipose tissue, the role and sequence of each critical
abnormality eventually leading to loss of SAT still remain elusive. It also
remains unknown which critical abnormalities should be counteracted in order to
reverse HAART-associated abnormalities in adipose tissue of these patients, and
whether thiazolidinediones would have this potential. |
4. Thiazolidinediones for HAART-Induced
Metabolic Adverse Effects Thiazolidinediones have been used in
14 clinical trials in HIV-infected, HAART-treated patients [ 54– 67]. The basic characteristics of these
trials are given in Table 1. In total, 281 patients have used rosiglitazone, 82
patients pioglitazone, and 6 patients troglitazone in these trials. Four of
these trials were open label-uncontrolled studies [ 54, 59, 64, 67], 6 were randomized placebo-controlled
studies [ 55– 57, 61, 62, 66], and 4 had a comparison arm with
another active agent (metformin or fenofibrate) [ 58, 60, 63, 65]. Followup times varied from 6 weeks
to 12 months.  | Table 1 The basic characteristics of the studies with thiazolidinediones
in HIV-infected, HAART-treated patients. HAART = highly active antiretroviral therapy, IR = insulin resistance,
LA = lipoatrophy, OGTT = oral glucose tolerance test, LD = lipodystrophy. |
The presence of lipoatrophy without
reference to insulin resistance was the inclusion criteria in five studies [ 55, 56, 58, 64, 66], one additional study required the
presence of at least one feature of lipodystrophy (but not necessarily lipoatrophy)
without reference to insulin resistance [ 62]. Insulin resistance (defined by
fasting insulin concentration, oral glucose tolerance test, or clamp studies)
without reference to lipodystrophy was the inclusion criteria in three studies [ 54, 63, 65]. One study required the presence of
both lipoatrophy and insulin resistance [ 57], and another study included
patients with changes in body fat (but not necessarily lipoatrophy) together
with insulin resistance [ 60]. The troglitazone study included
patients with newly diagnosed diabetes with lipodystrophy and dyslipidemia [ 67], and two studies did not specify
any metabolic abnormalities in the inclusion criteria [ 59, 61]. The exclusion criteria were variable,
but often included liver function tests >2-3 times upper
limit of normal, serum creatinine >1-2 times upper
limit of normal, haemoglobin <90–95 g/L, serum
triglycerides >10–15 mmol/L,
presence of heart failure, and pregnancy. 4.1. Effects on Body Composition Body composition data from the eight
studies which included a control arm and an objective measurement of subcutaneous
fat (dual-energy X-ray absorptiometry [DEXA], computed tomography [CT], magnetic
resonance imaging [MRI]) are included in Table 2. No significant changes in the
amount of subcutaneous fat could be detected in four studies: two of these
studies used a single method to measure adipose tissue volume (one with MRI [ 55], one with DEXA [ 62]), and the other two studies measured
fat volume using both DEXA and CT [ 56, 65]. In contrast to these four studies,
three other studies reported statistically significant increases in SAT in
patients taking either rosiglitazone [ 57, 60] or pioglitazone [ 66] as compared to placebo. SAT was quantified
by both DEXA and CT scan in all these three studies, but none of the studies
could confirm the statistically significant increase in SAT versus placebo by
the second method in the same study. The absolute changes in SAT in the thiazolidinedione
arm were reported in two studies: an increase of 50 g in leg fat mass after 12-week
treatment with rosiglitazone [ 57], and 380 g increase in limb fat
mass in the pioglitazone arm after 48 weeks of therapy [ 66]. In the study by van Wijk et al.
rosiglitazone was compared to metformin without a placebo arm [ 58]. In this study, there was a
statistically significant increase in SAT measured by CT scan in the
rosiglitazone arm versus baseline, and also relative to metformin. DEXA
scanning was not performed in this study. | Table 2Body composition data from thiazolidinedione
studies which included a control arm and an objective measurement of body
composition in HIV-infected, HAART-treated patients. HAART = highly active antiretroviral therapy, SAT
= subcutaneous adipose tissue, (more ...) |
One study found a statistically
almost significant increase in visceral adipose tissue (VAT) in the
rosiglitazone group when compared to placebo [ 60], while there were no significant
changes in VAT between the glitazone and placebo arms in the other studies.
None of the placebo-controlled trials reported significant changes in BMI
either within the glitazone arm or between the placebo and glitazone group,
although the difference approached statistical significance in the pioglitazone
trial by Slama et al. [ 66]. In the study comparing
rosiglitazone and metformin, there was a significant increase in body mass
index (BMI) within the rosiglitazone arm from baseline, and also the change between
the rosiglitazone and metformin arm was statistically significant [ 58]. The studies finding no significant
increase in SAT reported changes in body weight ranging from a loss of 3.0 kg
to the gain of 3.8 kg in the thiazolidine arm [ 55, 56, 62, 65]. In contrast to variable effects
seen on body weight with glitazones, all three studies having a metformin arm [ 58, 60, 63] reported a decrease in body weight from
1.2 to 2.2 kg in patients using metformin. The effects of thiazolidinediones on
body composition in HAART-treated patients contrast data from HIV-negative
diabetic patients. In these patients, thiazolidinediones have increased body
weight constantly by 2–4 kg after 16–26 weeks of
therapy [ 12]. This increase has been attributed mainly
to an increase in the fat mass and in some patients to edema [ 12]. The increase in total fat mass has
been in the order of 1.5–4 kg after 3-4 months of rosiglitazone
therapy [ 9, 68, 69], and it consists almost exclusively
of the increase in the subcutaneous fat depot [ 7, 8, 69, 70]. Similar effects on body fat have
also been described in nondiabetic patients treated with pioglitazone for
insulin resistance [ 71] or nonalcoholic steatohepatitis [ 72].
Table 3 lists some confounding
factors that possibly could explain the conflicting results of thiazolidinediones
on SAT in different trials with HIV-infected, HAART-treated patients. The drug
dose, study duration, inclusion criteria and baseline BMI appeared to be
similar between studies showing a statistically significant increase versus
those not showing a change in SAT. The prevalence of concomitant use of stavudine,
the NRTI most strongly associated with fat loss, may explain some of the discrepancies,
since the studies reporting an increase in SAT were those with least frequent
use of stavudine [ 57, 58, 66]. Also in the study by Carr et al.,
after 24 weeks of treatment with rosiglitazone, there was a statistically
almost significant increase in SAT in those patients not taking stavudine or zidovudine
when compared to the placebo group (+480 g versus 190 g, P = .06), but this
difference was not maintained at week 48 [ 56]. Similarly, in the study by Slama
et al., patients not taking stavudine at baseline had a mean increase of limb
fat mass of 450 g in the pioglitazone group versus 40 g increase in the placebo
group ( P = .013) [ 66]. Based on these data one can hypothesize
that thiazolidinediones may have a fat-inducing effect in lipoatrophic SAT, but
the ongoing stavudine (and zidovudine) treatment may negate this beneficial effect. | Table 3Comparison of the baseline characteristics of the thiazolidinedione
arms of the studies showing versus not showing an increase in subcutaneous fat mass
in HIV-infected HAART-treated patients. HAART =
highly active antiretroviral therapy, SAT = subcutaneous (more ...) |
In addition to quantifying adipose
tissue compartments, liver fat content was measured in one study [ 55]. Liver fat decreased with
rosiglitazone and increased with placebo (−2.1% versus +2.1% in the
rosiglitazone versus placebo, P < .05) [ 55]. Serum alanine aminotransferase (ALT)
concentrations were reported in 5 rosiglitazone studies [ 55– 58, 60]. In three of these studies, there
was a statistically significant decrease in ALT concentration in the rosiglitazone
arm compared either to the baseline value or to the placebo arm possibly suggesting
a decrease in liver fat content [ 55, 56, 58]. Outside these trials, a single case
report describes development of several dozen lipomas in a patient with HAART-associated
lipoatrophy during 3-month therapy with rosiglitazone. After rosiglitazone was
discontinued, all but 5 lipomas resolved completely [ 73]. 4.2. Effects on Insulin Resistance and Blood Lipids The effects of thiazolidinediones on
glycemic indeces in the ten comparative studies reporting data on glucose and
insulin are shown in Table 4. In contrast to the very modest effects on SAT described
above, eight [ 55– 58, 60, 61, 63, 65] out of 10 studies showed improvements
in insulin resistance in the thiazolidinedione arm when compared to the
baseline value or to the placebo arm. One study reported a significant positive
correlation between the change in fasting insulin concentration and the change
in liver fat content [ 55]. Only two studies did not show
significant improvements in insulin sensitivity [ 62, 66]. Of note, insulin resistance was an
inclusion criteria in only four [ 57, 60, 63, 65] out of these 10 studies. | Table 4The effects of thiazolidinediones on glycemic indeces in controlled trials with HIV infected, HAART-treated patients. HAART = highly active antiretroviral therapy, HOMA
= homeostasis model assessment (fasting insulin [μIU/ml] × fasting (more ...) |
Since none of the comparative
studies recruited patients with type 2 diabetes, it is difficult to compare these
effects on glycemic indeces in HAART-treated patients to those in HIV-negative diabetic
patients treated with glitazones. The average decrease in haemoglobin A 1c has been 1–1.5% in non-HIV patients with type 2 diabetes
treated with glitazones [ 12]. The effects of thiazolidinediones on
blood lipids in the nine comparative studies reporting data on cholesterol and
triglycerides are shown in Table 5. Five [ 55– 58, 60] out of seven studies with rosiglitazone
reported a statistically significant increase in total cholesterol concentration
in the rosiglitazone arm when compared either to the baseline value or to the comparative
arm. The absolute increases in total cholesterol concentration in the rosiglitazone
arms varied from 0.4 to 1.4 mmol/L. Neither of the two pioglitazone studies
reported significant changes in total cholesterol concentrations [ 65, 66]. HDL (high-density lipoprotein) cholesterol
concentration increased statistically significantly in both studies with pioglitazone
(increases of 0.09 and 0.15 mmol/L) [ 65, 66], but decreased significantly in two
out of the seven rosiglitazone studies with absolute decreases of 0.1 and 0.15 mmol/L [ 58, 60]. LDL (low-density lipoprotein)
cholesterol was measured in five rosiglitazone studies [ 56– 58, 60, 62]. Four of these studies reported
significant increases in LDL cholesterol concentrations when compared to the
baseline value (absolute increases between 0.2–0.8 mmol/L) or to the comparative arm [ 56– 58, 60]. The increase of 1.7 mmol/L in LDL
cholesterol was statistically almost significant in one of the two pioglitazone
studies [ 65]. Statistically significant
increases in triglyceride concentrations were reported in three out of seven rosiglitazone
studies (versus baseline or versus the comparative arm) [ 55, 56, 58]. The absolute increases were between
0.5–3.0 mmol/l. There were no significant changes
in triglyceride concentrations in the two pioglitazone studies. A proatherogenic
effect of rosiglitazone on blood lipids was further described by Hadigan et al.
[ 74]. Rosiglitazone treatment increased
significantly the concentration of small dense LDL cholesterol, and decreased
the concentration of large HDL cholesterol and also of HDL particle size [ 74]. In contrast, pioglitazone
treatment was associated with an increase in the LDL particle size (from 19.9
at baseline to 20.6 nm at 12 months, P = .06) [ 65]. | Table 5 The effects of thiazolidinediones
on blood lipids in comparative studies with HIV infected, HAART-treated
patients. HDL
= high-density lipoprotein, LDL = low-density lipoprotein, NS = nonsignificant,
NR = not reported, CI = confidence interval. |
The results of these studies with
HAART-treated patients suggest pioglitazone to have a more favorable lipid
profile than rosiglitazone as has been observed in patients with type 2
diabetes [ 12]. A striking difference in HAART-treated
patients relative to HIV-negative diabetic patients was the significant increase
in triglyceride concentration by 1.5 to 2.3 mmol/L in the rosiglitazone arm in
some studies [ 55, 56]. One may hypothesize that the
increases in serum triglycerides were possibly aggravated by the high
prevalence of stavudine use in these studies. The ongoing stavudine treatment may
have prevented the storage of circulating lipids within the adipocytes. In the
study by Sutinen et al., one patient had to discontinue rosiglitazone treatment
due to serum triglyceride increase up to 32.5 mmol/L [ 55] and another patient using
rosiglitazone in the study by Cavalcanti et al. discontinued due to abnormal
lipid values [ 62]. Carr et al. reported grade 3-4 increases in
triglyceride concentrations in 57% of the participants in the rosiglitazone arm
compared to 36% in the placebo arm [ 56]. The large study by Cavalcanti et
al. did not report any deleterious effects on blood lipid concentrations by
rosiglitazone, but in the same study 15% of patients in the rosiglitazone arm
started lipid-lowering therapy during the study compared to 5% in the placebo
arm [ 62]. In addition to these prospective
clinical trials, a small retrospective study reported effects of fenofibrate
alone versus fenofibrate in combination with rosiglitazone in HIV-infected
patients [ 75]. When fenofibrate was given alone,
triglyceride concentrations decreased by 27% and HDL cholesterol increased by
19%. In contrast, when fenofibrate was combined with rosiglitazone, triglycerides
increased by 48% and HDL cholesterol decreased by 33% [ 75]. Three of the rosiglitazone studies [ 57, 60, 76] also reported the effects of
rosiglitazone on free fatty acid (FFA) concentrations. In two of these studies,
a statistically significant decrease in FFA concentration was found in the
rosiglitazone arm when compared to baseline value or to placebo [ 57, 76]. Serum adiponectin concentration was
measured in six rosiglitazone studies [ 56– 58, 60, 61, 76]. All these studies showed a statistically
significant increase of 0.8–4.1 μg/ml in the
rosiglitazone arms. One study found an inverse correlation between the change
in adiponectin concentration and the change in fasting insulin concentration
and liver fat content [ 76]. Additional findings from these
clinical trials with HAART-treated patients include either a decline [ 77] or no change [ 55, 78] in leptin concentration with
rosiglitazone. Circulating concentrations of inflammatory markers (TNF α,
C-reactive protein, or IL-6) did not change in any study reporting these
measurements [ 78– 80]. Plasma concentrations of PAI-1
(plasminogen activator inhibitor-1) and tPA (tissue plasminogen activator) were
reported to either decline [ 79] or remain unchanged [ 78] with rosiglitazone therapy. Plasma
resistin concentration decreased with rosiglitazone in one study [ 78]. Rosiglitazone decreased systolic
blood pressure, but had a nonsignificant effect on flow-mediated arterial
dilatation compared to placebo in one study [ 77]. 4.3. Thiazolidinedione-Induced Gene Expression in SAT in
HAART-Treated Patients Two studies have evaluated the
effects of rosiglitazone on gene expression in SAT in HAART-treated patients [ 76, 81]. Sutinen et al. reported
statistically significant increases in the expression of adiponectin and PPAR γ coactivator 1 (PGC-1), and a
decrease in IL-6 expression with rosiglitazone treatment [ 76]. In addition, there was a significant
increase in PPAR γ expression in the rosiglitazone arm relative to the placebo
arm [ 76]. Mallon et al. studied gene
expression in SAT two and 48 weeks after rosiglitazone or placebo treatment,
and compared patients taking tNRTIs at baseline to those without tNRTI treatment
[ 81]. After two weeks, only those
randomized to rosiglitazone in the no-tNRTI group experienced a significant
rise in PPAR γ and PGC-1 expression. At 48 weeks, PPAR γ expression was increased
in the no-tNRTI groups when compared to tNRTI groups, but there was no
difference between the rosiglitazone and placebo arms [ 81]. The increase in the expression of
adiponectin, PPAR γ (albeit limited), and that of PGC-1 are consistent with data
from type 2 diabetic patients treated with glitazones [ 82, 83]. There are,
however, also some differences in these two patient populations. In non-HIV
patients, the expression of lipoprotein lipase (LPL) [ 82, 84] and adipocyte fatty
acid binding protein (aP2) [ 83] increased with glitazone
treatment. The expression of these genes remained unchanged in HAART-treated patients
[ 76]. Taken together, it seems plausible
that thiazolidinedione treatment had a functional effect in lipoatrophic SAT by
increasing the production of adiponectin and decreasing IL-6 expression. Both
of these changes may have been involved in the improvement of whole body
insulin sensitivity. The correlation between the change in adiponectin
concentration and the change in liver fat content implies a possibility for
adiponectin to have mediated this beneficial effect on liver fat [ 76]. These functional changes in
adipose tissue occurred despite the lack of a significant increase in fat mass.
One may also hypothesize that the blunted increase in PPAR γ expression, especially in patients
receiving tNRTI therapy, as well as the lack of an increase in LPL and aP2 expression
may all have contributed to the nonsignificant effect on SAT mass and to high-serum
triglyceride concentration in these patients. 4.4. Safety Since in vitro and animal models, as well as clinical
studies clearly indicate that thiazolidinediones correct endothelial
dysfunction, suppress chronic inflammatory processes, reduce fatty streak formation,
and enhance plaque stabilization and regression [ 85], one would expect favorable effects
on cardiovascular endpoints also in human studies. In contrast, the meta analysis by Nissen and Wolski [ 86] demonstrated that rosiglitazone as compared to the control group significantly
increased (and not decreased) the odds ratio for myocardial infarction (OR 1.43;
95% confidence interval [CI], 1.03 to 1.98; P = .03), and the odds ratio
for death from cardiovascular causes (OR 1.64; 95% CI, 0.98 to 2.74; P = .06).
A more recent meta analysis confirmed the increased risk of myocardial
infarction (RR 1.42; 95% CI, 1.06 to 1.91; P = .02) and heart failure (RR
2.09; 95% CI, 1.52 to 2.88; P < .001) with rosiglitazone, but found no
significant increase in the risk of cardiovascular mortality (RR 0.90; 95% CI,
0.63 to 1.26; P = .53) [ 87]. In contrast to findings with rosiglitazone, a
meta-analysis of pioglitazone found a decreased hazard ratio for death,
myocardial infarction, or stroke in patients receiving pioglitazone when
compared to those receiving control therapy (HR 0.82; 95% CI, 0.72 to 0.94; P = .005)
[ 88]. However, the hazard ratio for serious heart
failure was increased in patients receiving pioglitazone versus the control
patients (HR, 1.41; 95% CI, 1.14 to 1.76; P = .002) [ 88]. Whether
these deleterious effects of glitazones on cardiovascular morbidity would be
diminished in patients receiving HAART, since patients are usually younger,
fewer have diabetes, and so forth, or enhanced since HAART by itself increases
risk for myocardial infarction [ 4], remains to be studied. None of the studies
with HAART-treated patients using glitazones so far have reported any
significant cardiovascular events. In general, both rosiglitazone and
pioglitazone were well tolerated in all trials with HAART-treated patients. However,
the total number of HAART-treated patients taking rosiglitazone and pioglitazone
was only 281 and 82, respectively, and none of the studies had followup beyond
one year. Furthermore, it is important to keep in mind that due to exclusion
criteria of these trials there are basically no data on glitazones in HIV-infected
patients with significantly increased liver function tests, high creatinine or triglyceride
concentrations, or low hemoglobin at baseline; all these laboratory
abnormalities are relatively common in HAART-treated patients. Regarding the known adverse effect
profile of thiazolidinediones in non-HIV infected patients, it was reassuring
that no cases of clinically significant oedema, heart failure or other
cardiovascular events were reported. A decrease in haemoglobin concentration is
another known side effect with all glitazones, which is not explained by
hemodilution but possibly caused by mild suppressive effect on bone marrow [ 89, 90]. This might be of significance in HAART-treated
patients, since both HIV per se
and antiretroviral agents may cause bone marrow suppression [ 91]. A statistically, but not
clinically significant decrease in haemoglobin concentration in the rosiglitazone
arm was reported in one study, possibly also reflecting good adherence to study
medication [ 55]. A single case with a decrease of
haemoglobin concentration to less than 110 g/L was reported by Hadigan et al. [ 57]. Given the concerns for severe
liver toxicity induced by troglitazone [ 92], liver function tests were carefully
monitored in these patients receiving polypharmacy. A single participant in a
pioglitazone trial discontinued the study due to an increase in liver function
tests >3 times upper limit of normal [ 65]. In contrast, three studies
observed significant decreases in ALT concentrations either within the
rosiglitazone arm or when compared to placebo [ 55, 56, 58]. Adverse effects on blood lipids
were already discussed earlier; two patients had to discontinue rosiglitazone
due to abnormal lipid values [ 55, 62]. Harmful effects of thiazolidinediones
on bone metabolism have recently been discussed in patients with type 2 diabetes.
A recent analysis of the data from five glitazone studies suggests that treatment with
thiazolidinediones, primarily rosiglitazone, contributes to bone loss [ 93]. This effect appears to be most prominent in
postmenopausal women [ 93]. The effect on bone density may have special
relevance in HAART-treated patients, since both HIV-infection as such and also
antiretroviral therapy have been associated with decreased bone mineral density
[ 94]. None of the studies using glitazones in HAART-treated
patients have reported effects on bone density. Potential for drug-drug interactions
must always be considered, when new medications are combined with HAART. Most
PIs and nonnucleoside reverse transcriptase inhibitors (NNRTIs) are not only metabolized
by CYP450 3A4 but are also either inhibitors (PIs, ritonavir in particular) or
inducers (NNRTIs) of the same enzyme and to lesser extent of other isoforms of
CYP450 [ 95]. Both rosiglitazone and
pioglitazone are predominantly metabolized by CYP450 2C8 ( http://www.emea.europa.eu/). Rosiglitazone is not an inducer of any
tested human CYP450 isoforms, but has shown moderate inhibition of 2C8 and low
inhibition of 2C9 ( http://www.emea.europa.eu/). There is no in vitro evidence that pioglitazone
would either inhibit or induce any of the human CYP450 isoforms ( http://www.emea.europa.eu/). Interaction studies have not shown
clinically significant interactions with rosiglitazone and substrates for
CYP450 3A4. These interactions are not expected with pioglitazone either ( http://www.emea.europa.eu/). There are currently very limited
pharmacological data on the concomitant use of thiazolidinediones and
antiretroviral drugs. Data from a limited number of patients by Oette et al.
suggest that rosiglitazone could be safely administered together with either
lopinavir or efavirenz [ 96]. Rosiglitazone, however, seemed to decrease
nevirapine concentrations and the authors recommend to monitor nevirapine serum
concentrations if these drugs are used concomitantly [ 96]. Serum PI concentrations were
measured in one study with rosiglitazone [ 55] and both PI and NNRTI
concentrations were measured in one pioglitazone study [ 66]. Neither study observed any
significant change in the serum concentrations of these antiretroviral drugs during the
study period. None of the studies reported any statistically significant
changes in either HIV viral load or CD4 count within the glitazone arm or
between different study arms. Nevertheless, six patients in the pioglitazone
arm versus two in the placebo arm ( P = .1) experienced viral breakthrough
( >400 copies/ml) during a pioglitazone trial [ 66]. It is not reported if these patients
were possibly taking nevirapine-based HAART (potential interaction between
nevirapine and rosiglitazone, see above). Interestingly, in vitro both PPAR γ (rosiglitazone, ciglitazone,
troglitazone) and PPAR α (fenofibrate) agonists have been shown to inhibit
HIV replication [ 97, 98]. |
5. Conclusions Regarding the Role of
Thiazolidinediones in the Treatment of
HAART-Associated Metabolic Complications The available evidence does not support the use
of thiazolidinediones for HAART-associated lipoatrophy although they may
have beneficial effects in subgroups of patients such as those that do not receive
concomitant tNRTI therapy. The lack of effect may at least partially be
explained by the decreased expression of PPAR γ which has been
demonstrated not only in SAT of lipoatrophic HAART-treated patients [ 41, 42],
but also in SAT of healthy volunteers after only a 2-week exposure to NRTIs
including a thymidine analog [ 40].
However, if a thiazolidinedione
is used for lipoatrophy, pioglitazone
should perhaps be preferred because of its more favorable effects on serum lipids.
Currently, the best treatment option for HAART-associated lipoatrophy is to
replace tNRTIs by abacavir or tenofovir [ 27– 29] or possibly to avoid use of NRTI altogether [ 99]. However, if this causal treatment of
lipoatrophy is not feasible due to HIV resistance profile or intolerance to
other antiretroviral agents, one may consider using uridine, which showed a significant
increase in SAT in a small randomized, placebo-controlled trial in lipoatrophic
patients continuing tNRTI-based HAART [ 100]. Pravastatin has also been shown to increase
SAT in HAART-treated patients in a single small trial [ 101]. However, patients in this trial were not
recruited for lipoatrophy but hyperlipidemia and hence the effect of
pravastatin in severely lipoatrophic patients remains to be studied. Finally and most importantly, one should aim
to prevent lipoatrophy altogether by avoiding the use of tNRTIs in the primary
combinations of HAART as has recently been suggested [ 102]. Glitazones, pioglitazone in particular, could
however, be used for the treatment of HAART-associated diabetes, especially in
patients with reduced amount of SAT. The consistent data on the beneficial
effects on insulin sensitivity in HAART-treated patients support this, albeit
none of these studies recruited diabetic patients. The direct evidence of the
benefits in diabetic HAART-treated patients is therefore still lacking. When
using glitazones for diabetes in HAART-treated patients, one must keep in mind
the potential risk for heart failure associated with both glitazones and increased
risk for myocardial infarction with rosiglitazone. Nevertheless, glitazones
might be the preferred choice, since metformin has been associated with further
loss of SAT in HAART-treated lipodystrophic patients [ 58, 103] and there are no clinical data at all on other
oral antidiabetic agents in this patient population. Finally, the potential therapeutic role of thiazolidinediones on liver-related morbidity in HAART-treated
patients should be evaluated. Patients who are infected with both hepatitis C (HCV)
and HIV seem to have higher liver fat content than those having HCV
monoinfection [ 104, 105] although some controversy exists [ 106]. Among HIV-infected patients without chronic HCV
infection, those with lipodystrophy have increased liver fat content when
compared to age and BMI-matched HIV-negative subjects or HAART-treated
nonlipodystrophic patients [ 48]. It, therefore, appears that both prevalent
coinfection with HCV and HAART-induced metabolic complications put HIV-infected
patients at increased risk for liver steatosis. In HIV-negative patients with nonalcohol
hepatic steatosis, 6-month treatment with pioglitazone decreased liver fat
content, increased hepatic insulin sensitivity, and improved histologic
findings with regards to liver steatosis, ballooning necrosis and inflammation [ 107]. In the study by Sutinen et al., treatment
with rosiglitazone decreased significantly liver fat content when compared to
placebo in HAART-treated patients, although patients were not recruited for
increased liver fat but for the presence of lipoatrophy [ 55]. Two additional trials reported significant decreases
in liver function tests in the glitazone arms [ 56, 58]. Although promising, it remains unknown
whether glitazones would also improve inflammatory changes in the liver in
these patients, since no biopsy data are so far available. |
Acknowledgment Professor Hannele Yki-Järvinen is
gratefully acknowledged for constructive criticism and suggestions during the
preparation of this manuscript. |
References 1. Jaggy C, von Overbeck J, Ledergerber B, et al. Mortality in the Swiss HIV Cohort Study (SHCS) and the Swiss general population. The Lancet. 2003;362(9387):877–878. 2. Pierson T, McArthur J, Siliciano RF. Reservoirs for HIV-1: mechanisms for viral persistence in the presence of antiviral immune responses and antiretroviral therapy. Annual Review of Immunology. 2000;18:665–708. 3. El-Sadr WM, Lundgren JD, Neaton JD, et al. CD4+ count-guided interruption of antiretroviral treatment. The New England Journal of Medicine. 2006;355(22):2283–2296. [PubMed]4. Friis-Møller N, Sabin CA, Weber R, et al. Combination antiretroviral therapy and the risk of myocardial infarction. The New England Journal of Medicine. 2003;349(21):1993–2003. [PubMed]5. Grinspoon S, Carr A. Cardiovascular risk and body-fat abnormalities in HIV-infected adults. The New England Journal of Medicine. 2005;352(1):48–62. [PubMed]6. Bacchetti P, Gripshover B, Grunfeld C, et al. Fat distribution in men with HIV infection. Journal of Acquired Immune Deficiency Syndromes. 2005;40(2):121–131. [PubMed]7. Lebovitz HE, Dole JF, Patwardhan R, Rappaport EB, Freed MI. Rosiglitazone monotherapy is effective in patients with type 2 diabetes. The Journal of Clinical Endocrinology & Metabolism. 2001;86(1):280–288. [PubMed]8. Raskin P, Rendell M, Riddle MC, Dole JF, Freed MI, Rosenstock J. A randomized trial of rosiglitazone therapy in patients with inadequately controlled insulin-treated type 2 diabetes. Diabetes Care. 2001;24(7):1226–1232. [PubMed]9. Mayerson AB, Hundal RS, Dufour S, et al. The effects of rosiglitazone on insulin sensitivity, lipolysis, and hepatic and skeletal muscle triglyceride content in patients with type 2 diabetes. Diabetes. 2002;51(3):797–802. [PubMed]10. Arioglu E, Duncan-Morin J, Sebring N, et al. Efficacy and safety of troglitazone in the treatment of lipodystrophy syndromes. Annals of Internal Medicine. 2000;133(4):263–274. [PubMed]11. Berger J, Moller DE. The mechanisms of action of PPARs. Annual Review of Medicine. 2002;53:409–435. 12. Yki-Järvinen H. Thiazolidinediones. The New England Journal of Medicine. 2004;351(11):1106–1118. [PubMed]13. Heikkinen S, Auwerx J, Argmann CA. PPAR γ in human and mouse physiology. Biochimica et Biophysica Acta. 2007;1771(8):999–1013. [PubMed]14. Lehmann JM, Moore LB, Smith-Oliver TA, Wilkison WO, Willson TM, Kliewer SA. An antidiabetic thiazolidinedione is a high affinity ligand for peroxisome proliferator-activated receptor γ (PPAR γ). The Journal of Biological Chemistry. 1995;270(22):12953–12956. [PubMed]15. Spiegelman BM. PPAR- γ: adipogenic regulator and thiazolidinedione receptor. Diabetes. 1998;47(4):507–514. [PubMed]16. Reus S, Arroyo E, Boix V, Portilla J. Lipodystrophy and hyperglycemia produced by protease inhibitors. Anales de Medicina Interna. 2000;17(3):123–126. [PubMed]17. Carr A, Samaras K, Thorisdottir A, Kaufmann GR, Chisholm DJ, Cooper DA. Diagnosis, prediction, and natural course of HIV-1 protease-inhibitor-associated lipodystrophy, hyperlipidaemia, and diabetes mellitus: a cohort study. The Lancet. 1999;353(9170):2093–2099. 18. Carr A, Cooper DA. Adverse effects of antiretroviral therapy. The Lancet. 2000;356(9239):1423–1430. 19. Schambelan M, Benson CA, Carr A, et al. Management of metabolic complications associated with antiretroviral therapy for HIV-1 infection: recommendations of an International AIDS Society-USA Panel. Journal of Acquired Immune Deficiency Syndromes. 2002;31(3):257–275. [PubMed]20. Gallant JE, Staszewski S, Pozniak AL, et al. Efficacy and safety of tenofovir DF vs stavudine in combination therapy in antiretroviral-naive patients: a 3-year randomized trial. The Journal of the American Medical Association. 2004;292(2):191–201. 21. Podzamczer D, Ferrer E, Sanchez P, et al. Less lipoatrophy and better lipid profile with abacavir as compared to stavudine: 96-week results of a randomized study. Journal of Acquired Immune Deficiency Syndromes. 2007;44(2):139–147. [PubMed]22. Saint-Marc T, Partisani M, Poizot-Martin I, et al. A syndrome of peripheral fat wasting (lipodystrophy) in patients receiving long-term nucleoside analogue therapy. AIDS. 1999;13(13):1659–1667. [PubMed]23. Savès M, Raffi F, Capeau J, et al. Factors related to lipodystrophy and metabolic alterations in patients with human immunodeficiency virus infection receiving highly active antiretroviral therapy. Clinical Infectious Diseases. 2002;34(10):1396–1405. [PubMed]24. Mauss S, Corzillius M, Wolf E, et al. Risk factors for the HIV-associated lipodystrophy syndrome in a closed cohort of patients after 3 years of antiretroviral treatment. HIV Medicine. 2002;3(1):49–55. [PubMed]25. van der Valk M, Gisolf EH, Reiss P, et al. Increased risk of lipodystrophy when nucleoside analogue reverse transcriptase inhibitors are included with protease inhibitors in the treatment of HIV-1 infection. AIDS. 2001;15(7):847–855. [PubMed]26. Dubé MP, Komarow L, Mulligan K, et al. Long-term body fat outcomes in antiretroviral-naive participants randomized to nelfinavir or efavirenz or both plus dual nucleosides: dual X-ray absorptiometry results from A5005s, a substudy of adult clinical trials group 384. Journal of Acquired Immune Deficiency Syndromes. 2007;45(5):508–514. [PubMed]27. Carr A, Workman C, Smith DE, et al. Abacavir substitution for nucleoside analogs in patients with HIV lipoatrophy: a randomized trial. The Journal of the American Medical Association. 2002;288(2):207–215. 28. Moyle GJ, Sabin CA, Cartledge J, et al. A randomized comparative trial of tenofovir DF or abacavir as replacement for a thymidine analogue in persons with lipoatrophy. AIDS. 2006;20(16):2043–2050. [PubMed]29. Sutinen J. Interventions for managing antiretroviral therapy-associated lipoatrophy. Current Opinion in Infectious Diseases. 2005;18(1):25–33. [PubMed]30. Dubé MP, Parker RA, Tebas P, et al. Glucose metabolism, lipid, and body fat changes in antiretroviral-naive subjects randomized to nelfinavir or efavirenz plus dual nucleosides. AIDS. 2005;19(16):1807–1818. [PubMed]31. Haubrich RH, Riddler S, DiRienzo G, et al. Metabolic outcomes of ACTG 5142: a prospective, randomized, phase III trial of NRTI-, PI-, and NNRTI-sparing regimens for initial treatment of HIV-1 infection. In: Proceedings of the 14th Conference on Retroviruses and Opportunistic Infections (CROI '07); February 2007; Los Angeles, Calif, USA. Abstract 38. 32. Hansen BR, Haugaard SB, Iversen J, Nielsen JO, Andersen O. Impact of switching antiretroviral therapy on lipodystrophy and other metabolic complications: a review. Scandinavian Journal of Infectious Diseases. 2004;36(4):244–253. [PubMed]33. Brinkman K, Smeitink JA, Romijn JA, Reiss P. Mitochondrial toxicity induced by nucleoside-analogue reverse-transcriptase inhibitors is a key factor in the pathogenesis of antiretroviral-therapy-related lipodystrophy. The Lancet. 1999;354(9184):1112–1115. 34. Pinti M, Salomoni P, Cossarizza A. Anti-HIV drugs and the mitochondria. Biochimica et Biophysica Acta. 2006;1757(5-6):700–707. [PubMed]35. Caron M, Auclair M, Lagathu C, et al. The HIV-1 nucleoside reverse transcriptase inhibitors stavudine and zidovudine alter adipocyte functions in vitro. AIDS. 2004;18(16):2127–2136. [PubMed]36. Shikuma CM, Hu N, Milne C, et al. Mitochondrial DNA decrease in subcutaneous adipose tissue of HIV-infected individuals with peripheral lipoatrophy. AIDS. 2001;15(14):1801–1809. [PubMed]37. Walker UA, Bickel M, Lütke Volksbeck SI, et al. Evidence of nucleoside analogue reverse transcriptase inhibitor-associated genetic and structural defects of mitochondria in adipose tissue of HIV-infected patients. Journal of Acquired Immune Deficiency Syndromes. 2002;29(2):117–121. [PubMed]38. Nolan D, Hammond E, Martin A, et al. Mitochondrial DNA depletion and morphologic changes in adipocytes associated with nucleoside reverse transcriptase inhibitor therapy. AIDS. 2003;17(9):1329–1338. [PubMed]39. Hammond E, Nolan D, James I, Metcalf C, Mallal S. Reduction of mitochondrial DNA content and respiratory chain activity occurs in adipocytes within 6–12 months of commencing nucleoside reverse transcriptase inhibitor therapy. AIDS. 2004;18(5):815–817. [PubMed]40. Mallon PWG, Unemori P, Sedwell R, et al. In vivo, nucleoside reverse-transcriptase inhibitors alter expression of both mitochondrial and lipid metabolism genes in the absence of depletion of mitochondrial DNA. The Journal of Infectious Diseases. 2005;191(10):1686–1696. [PubMed]41. Bastard J-P, Caron M, Vidal H, et al. Association between altered expression of adipogenic factor SREBP1 in lipoatrophic adipose tissue from HIV-1-infected patients and abnormal adipocyte differentiation and insulin resistance. The Lancet. 2002;359(9311):1026–1031. 42. Kannisto K, Sutinen J, Korsheninnikova E, et al. Expression of adipogenic transcription factors, peroxisome proliferator-activated receptor gamma co-activator 1, IL-6 and CD45 in subcutaneous adipose tissue in lipodystrophy associated with highly active antiretroviral therapy. AIDS. 2003;17(12):1753–1762. [PubMed]43. Jan V, Cervera P, Maachi M, et al. Altered fat differentiation and adipocytokine expression are inter-related and linked to morphological changes and insulin resistance in HIV-1-infected lipodystrophic patients. Antiviral Therapy. 2004;9(4):555–564. [PubMed]44. Lihn AS, Richelsen B, Pedersen SB, et al. Increased expression of TNF- α, IL-6, and IL-8 in HALS: implications for reduced adiponectin expression and plasma levels. American Journal of Physiology. 2003;285(5):E1072–E1080. [PubMed]45. Sutinen J, Korsheninnikova E, Funahashi T, Matsuzawa Y, Nyman T, Yki-Järvinen H. Circulating concentration of adiponectin and its expression in subcutaneous adipose tissue in patients with highly active antiretroviral therapy-associated lipodystrophy. The Journal of Clinical Endocrinology & Metabolism. 2003;88(4):1907–1910. [PubMed]46. Mynarcik DC, Combs T, McNurlan MA, Scherer PE, Komaroff E, Gelato MC. Adiponectin and leptin levels in HIV-infected subjects with insulin resistance and body fat redistribution. Journal of Acquired Immune Deficiency Syndromes. 2002;31(5):514–520. [PubMed]47. Addy CL, Gavrila A, Tsiodras S, Brodovicz K, Karchmer AW, Mantzoros CS. Hypoadiponectinemia is associated with insulin resistance, hypertriglyceridemia, and fat redistribution in human immunodeficiency virus-infected patients treated with highly active antiretroviral therapy. The Journal of Clinical Endocrinology & Metabolism. 2003;88(2):627–636. [PubMed]48. Sutinen J, Häkkinen A-M, Westerbacka J, et al. Increased fat accumulation in the liver in HIV-infected patients with antiretroviral therapy-associated lipodystrophy. AIDS. 2002;16(16):2183–2193. [PubMed]49. Estrada V, Serrano-Ríos M, Martínez Larrad MT, et al. Leptin and adipose tissue maldistribution in HIV-infected male patients with predominant fat loss treated with antiretroviral therapy. Journal of Acquired Immune Deficiency Syndromes. 2002;29(1):32–40. [PubMed]50. Gan SK, Samaras K, Thompson CH, et al. Altered myocellular and abdominal fat partitioning predict disturbance in insulin action in HIV protease inhibitor-related lipodystrophy. Diabetes. 2002;51(11):3163–3169. [PubMed]51. Christeff N, Melchior J-C, de Truchis P, Perronne C, Nunez EA, Gougeon M-L. Lipodystrophy defined by a clinical score in HIV-infected men on highly active antiretroviral therapy: correlation between dyslipidaemia and steroid hormone alterations. AIDS. 1999;13(16):2251–2260. [PubMed]52. Kosmiski L, Kuritzkes D, Lichtenstein K, Eckel R. Adipocyte-derived hormone levels in HIV lipodystrophy. Antiviral Therapy. 2003;8(1):9–15. [PubMed]53. Domingo P, Matias-Guiu X, Pujol RM, et al. Subcutaneous adipocyte apoptosis in HIV-1 protease inhibitor-associated lipodystrophy. AIDS. 1999;13(16):2261–2267. [PubMed]54. Gelato MC, Mynarcik DC, Quick JL, et al. Improved insulin sensitivity and body fat distribution in HIV-infected patients treated with rosiglitazone:
a pilot study. Journal of Acquired Immune Deficiency Syndromes. 2002;31(2):163–170. [PubMed]55. Sutinen J, Häkkinen A-M, Westerbacka J, et al. Rosiglitazone in the treatment of HAART-associated lipodystrophy—a randomized double-blind placebo-controlled study. Antiviral Therapy. 2003;8(3):199–207. [PubMed]56. Carr A, Workman C, Carey D, et al. No effect of rosiglitazone for treatment of HIV-1 lipoatrophy: randomised, double-blind, placebo-controlled trial. The Lancet. 2004;363(9407):429–438. 57. Hadigan C, Yawetz S, Thomas A, Havers F, Sax PE, Grinspoon S. Metabolic effects of rosiglitazone in HIV lipodystrophy: a randomized, controlled trial. Annals of Internal Medicine. 2004;140(10):786–794. [PubMed]58. van Wijk JPH, de Koning EJP, Cabezas MC, et al. Comparison of rosiglitazone and metformin for treating HIV lipodystrophy: a randomized trial. Annals of Internal Medicine. 2005;143(5):337–346. [PubMed]59. Feldt T, Oette M, Kroidl A, et al. Evaluation of safety and efficacy of rosiglitazone in the treatment of HIV-associated lipodystrophy syndrome. Infection. 2006;34(2):55–61. [PubMed]60. Mulligan K, Yang Y, Wininger DA, et al. Effects of metformin and rosiglitazone in HIV-infected patients with hyperinsulinemia and elevated waist/hip ratio. AIDS. 2007;21(1):47–57. [PubMed]61. Haider DG, Schindler K, Mittermayer F, et al. Effect of rosiglitazone on visfatin and retinol-binding protein-4 plasma concentrations in HIV-positive patients. Clinical Pharmacology & Therapeutics. 2007;81(4):580–585. [PubMed]62. Cavalcanti RB, Raboud J, Shen S, Kain KC, Cheung A, Walmsley S. A randomized, placebo-controlled trial of rosiglitazone for HIV-related lipoatrophy. The Journal of Infectious Diseases. 2007;195(12):1754–1761. [PubMed]63. Silič A, Janež A, Tomažič J, et al. Effect of rosiglitazone and metformin on insulin resistance in patients infected with human immunodeficiency virus receiving highly active antiretroviral therapy containing protease inhibitor: randomized prospective controlled clinical trial. Croatian Medical Journal. 2007;48(6):791–799. [PubMed]64. Calmy A, Hirschel B, Karsegaard L, et al. A pilot study for the use of pioglitazone in the treatment of highly active antiretroviral therapy lipodystrophy syndromes. Antiviral Therapy. 2001;6(supplement 4):p. 32. 65. Gavrila A, Hsu W, Tsiodras S, et al. Improvement in highly active antiretroviral therapy-induced metabolic syndrome by treatment with pioglitazone but not with fenofibrate: a 2 × 2 factorial, randomized, double-blinded, placebo-controlled trial. Clinical Infectious Diseases. 2005;40(5):745–749. [PubMed]66. Slama L, Lanoy E, Valantin M-A, et al. Effect of pioglitazone on HIV-1-related lipodystrophy: a randomized double-blind placebo-controlled
trial (ANRS 113). Antiviral Therapy. 2008;13(1):67–76. [PubMed]67. Walli R, Michl GM, Mühlbayer D, Brinkmann L, Goebel FD. Effects of troglitazone on insulin sensitivity in HIV-infected patients with protease inhibitor-associated diabetes mellitus. Research in Experimental Medicine. 2000;199(5):253–262. [PubMed]68. Miyazaki Y, Glass L, Triplitt C, et al. Effect of rosiglitazone on glucose and non-esterified fatty acid metabolism in Type II diabetic patients. Diabetologia. 2001;44(12):2210–2219. [PubMed]69. Carey DG, Cowin GJ, Galloway GJ, et al. Effect of rosiglitazone on insulin sensitivity and body composition in type 2 diabetic patients. Obesity Research. 2002;10(10):1008–1015. [PubMed]70. Phillips LS, Grunberger G, Miller E, Patwardhan R, Rappaport EB, Salzman A. Once- and twice-daily dosing with rosiglitazone improves glycemic control in patients with type 2 diabetes. Diabetes Care. 2001;24(2):308–315. [PubMed]71. Shadid S, Stehouwer CDA, Jensen MD. Diet/exercise versus pioglitazone: effects of insulin sensitization with decreasing or increasing fat mass on adipokines and inflammatory markers. The Journal of Clinical Endocrinology & Metabolism. 2006;91(9):3418–3425. [PubMed]72. Balas B, Belfort R, Harrison SA, et al. Pioglitazone treatment increases whole body fat but not total body water in patients with non-alcoholic steatohepatitis. Journal of Hepatology. 2007;47(4):565–570. [PubMed]73. Mafong DD, Lee GA, Yu S, Tien P, Mauro T, Grunfeld C. Development of multiple lipomas during treatment with rosiglitazone in a patient with HIV-associated lipoatropny. AIDS. 2004;18(12):1742–1744. [PubMed]74. Hadigan C, Mazza S, Crum D, Grinspoon S. Rosiglitazone increases small dense low-density lipoprotein concentration and decreases high-density lipoprotein particle size in HIV-infected patients. AIDS. 2007;21(18):2543–2546. [PubMed]75. Normén L, Frohlich J, Montaner J, Harris M, Elliott T, Bondy G. Combination therapy with fenofibrate and rosiglitazone paradoxically lowers serum HDL cholesterol. Diabetes Care. 2004;27(9):2241–2242. [PubMed]76. Sutinen J, Kannisto K, Korsheninnikova E, et al. Effects of rosiglitazone on gene expression in subcutaneous adipose tissue in highly active antiretroviral therapy-associated lipodystrophy. American Journal of Physiology. 2004;286(6):E941–E949. [PubMed]77. Kovacic JC, Martin A, Carey D, et al. Influence of rosiglitazone on flow-mediated dilation and other markers of cardiovascular risk in HIV-infected patients with lipoatrophy. Antiviral Therapy. 2005;10(1):135–143. [PubMed]78. Kamin D, Hadigan C, Lehrke M, Mazza S, Lazar MA, Grinspoon S. Resistin levels in human immunodeficiency virus-infected patients with lipoatrophy decrease in response to rosiglitazone. The Journal of Clinical Endocrinology & Metabolism. 2005;90(6):3423–3426. [PubMed]79. Yki-Järvinen H, Sutinen J, Silveira A, et al. Regulation of plasma PAI-1 concentrations in HAART-associated lipodystrophy during rosiglitazone therapy. Arteriosclerosis, Thrombosis, and Vascular Biology. 2003;23(4):688–694. 80. Coll B, van Wijk JPH, Parra S, et al. Effects of rosiglitazone and metformin on postprandial paraoxonase-1 and monocyte chemoattractant protein-1 in human immunodeficiency virus-infected patients with lipodystrophy. European Journal of Pharmacology. 2006;544(1–3):104–110. [PubMed]81. Mallon P, Sedwell R, Rogers G, et al. The effect of rosiglitazone on PPAR-γ expression in human adipose tissue is limited by continued exposure to thymidine NRTI. In: Proceedings of the 12th Conference on Retroviruses and Opportunistic Infections; February 2005; Boston, Mass, USA. 82. Tiikkainen M, Häkkinen A-M, Korsheninnikova E, Nyman T, Mäkimattila S, Yki-Järvinen H. Effects of rosiglitazone and metformin on liver fat content, hepatic insulin resistance, insulin clearance, and gene expression in adipose tissue in patients with type 2 diabetes. Diabetes. 2004;53(8):2169–2176. [PubMed]83. Hammarstedt A, Pihlajamäki J, Graham TE, et al. High circulating levels of RBP4 and mRNA levels of aP2, PGC-1 α and UCP-2 predict improvement in insulin sensitivity following pioglitazone treatment of drug-naive type 2 diabetic subjects. Journal of Internal Medicine. 2008;263(4):440–449. [PubMed]84. Tan GD, Fielding BA, Currie JM, et al. The effects of rosiglitazone on fatty acid and triglyceride metabolism in type 2 diabetes. Diabetologia. 2005;48(1):83–95. [PubMed]85. Staels B. PPARgamma and atherosclerosis. Current Medical Research and Opinion. 2005;21(supplement 1):S13–S20. [PubMed]86. Nissen SE, Wolski K. Effect of rosiglitazone on the risk of myocardial infarction and death from cardiovascular causes. The New England Journal of Medicine. 2007;356(24):2457–2471. [PubMed]87. Singh S, Loke YK, Furberg CD. Long-term risk of cardiovascular events with rosiglitazone: a meta-analysis. Journal of the American Medical Association. 2007;298(10):1189–1195. [PubMed]88. Lincoff AM, Wolski K, Nicholls SJ, Nissen SE. Pioglitazone and risk of cardiovascular events in patients with type 2 diabetes mellitus: a meta-analysis of randomized trials. Journal of the American Medical Association. 2007;298(10):1180–1188. [PubMed]89. Doggrell SA. Clinical trials with thiazolidinediones in subjects with type 2 diabetes—is pioglitazone any different from rosiglitazone? Expert Opinion on Pharmacotherapy. 2008;9(3):405–420. [PubMed]90. Berria R, Glass L, Mahankali A, et al. Reduction in hematocrit and hemoglobin following pioglitazone treatment is not hemodilutional in type II diabetes mellitus. Clinical Pharmacology & Therapeutics. 2007;82(3):275–281. [PubMed]91. Koka PS, Reddy ST. Cytopenias in HIV infection: mechanisms and alleviation of hematopoietic inhibition. Current HIV Research. 2004;2(3):275–282. [PubMed]92. Gale EAM. Lessons from the glitazones: a story of drug development. The Lancet. 2001;357(9271):1870–1875. 93. Murphy CE, Rodgers PT. Effects of thiazolidinediones on bone loss and fracture. Annals of Pharmacotherapy. 2007;41(12):2014–2018. [PubMed]94. Brown TT, Qaqish RB. Antiretroviral therapy and the prevalence of osteopenia and osteoporosis: a meta-analytic review. AIDS. 2006;20(17):2165–2174. [PubMed]95. Barry M, Mulcahy F, Merry C, Gibbons S, Back D. Pharmacokinetics and potential interactions amongst antiretroviral agents used to treat patients with HIV infection. Clinical Pharmacokinetics. 1999;36(4):289–304. [PubMed]96. Oette M, Kurowski M, Feldt T, et al. Impact of rosiglitazone treatment on the bioavailability of antiretroviral compounds in HIV-positive patients. Journal of Antimicrobial Chemotherapy. 2005;56(2):416–419. [PubMed]97. Skolnik PR, Rabbi MF, Mathys J-M, Greenberg AS. Stimulation of peroxisome proliferator-activated receptors α and γ blocks HIV-1 replication and TNF α production in acutely infected primary blood cells, chronically infected U1 cells, and alveolar macrophages from HIV-infected subjects. Journal of Acquired Immune Deficiency Syndromes. 2002;31(1):1–10. [PubMed]98. Hayes MM, Lane BR, King SR, Markovitz DM, Coffey MJ. Peroxisome proliferator-activated receptor γ agonists inhibit HIV-1 replication in macrophages by transcriptional and post-transcriptional effects. The Journal of Biological Chemistry. 2002;277(19):16913–16919. [PubMed]99. Boyd MA, Carr A, Ruxrungtham K, et al. Changes in body composition and mitochondrial nucleic acid content in patients switched from failed nucleoside analogue therapy to ritonavir-boosted indinavir and efavirenz. The Journal of Infectious Diseases. 2006;194(5):642–650. [PubMed]100. Sutinen J, Walker UA, Sevastianova K, et al. Uridine supplementation for the treatment of antiretroviral therapy-associated lipoatrophy: a randomized, double-blind, placebo-controlled trial. Antiviral Therapy. 2007;12(1):97–105. [PubMed]101. Mallon PWG, Miller J, Kovacic JC, et al. Effect of pravastatin on body composition and markers of cardiovascular disease in HIV-infected men-a randomized, placebo-controlled study. AIDS. 2006;20(7):1003–1010. [PubMed]102. Clumeck N, Pozniak A, Raffi F. European AIDS Clinical Society (EACS) guidelines for the clinical management and treatment of HIV-infected adults. HIV Medicine. 2008;9(2):65–71. [PubMed]103. Hadigan C, Corcoran C, Basgoz N, Davis B, Sax P, Grinspoon S. Metformin in the treatment of HIV lipodystrophy syndrome: a randomized controlled trial. The Journal of the American Medical Association. 2000;284(4):472–477. 104. Gaslightwala I, Bini EJ. Impact of human immunodeficiency virus infection on the prevalence and severity of steatosis in patients with chronic hepatitis C virus infection. Journal of Hepatology. 2006;44(6):1026–1032. [PubMed]105. Castera L, Loko MA, Le Bail B, et al. Hepatic steatosis in HIV-HCV coinfected patients in France: comparison with HCV monoinfected patients matched for body mass index and HCV genotype. Alimentary Pharmacology & Therapeutics. 2007;26(11-12):1489–1498. [PubMed]106. Monto A, Dove LM, Bostrom A, Kakar S, Tien PC, Wright TL. Hepatic steatosis in HIV/hepatitis C coinfection: prevalence and significance compared with hepatitis C monoinfection. Hepatology. 2005;42(2):310–316. [PubMed]107. Belfort R, Harrison SA, Brown K, et al. A placebo-controlled trial of pioglitazone in subjects with nonalcoholic steatohepatitis. The New England Journal of Medicine. 2006;355(22):2297–2307. [PubMed] |
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Associated Lipodystrophy
