U.S.
Food and Drug Administration
FDA Consumer magazine
March-April 2002
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Blacks and Asians have worse outcomes than whites and Hispanics after liver transplantation, in terms of both graft rejection and survival, according to a new study of liver transplants done in the United States.
Scientists at the Johns Hopkins Medical Institutions in Baltimore analyzed data from the United Network of Organ Sharing (UNOS) registry on age, sex, race, blood group, and cause of death of donors and recipients for all liver transplants done between 1988 and 1996.
"Our results show that outcomes two years after surgery were considerably lower for African-Americans and Asians than for white Americans," says Paul Thuluvath, M.D., associate professor of medicine and medical director of liver transplantation in the division of gastroenterology and hepatology at Johns Hopkins and lead author of the paper.
While the low outcomes for Asians are influenced by the number of patients with hepatitis B, the cause for low survival in blacks remains unclear. What is clear, says Thuluvath, is that more studies need to be done to determine why blacks are faring less well than other races.
"Until then, the reasons for poor survival in African-Americans will remain speculative," says Thuluvath.
The scientists report that two-year graft survival for blacks (68 percent) and Asians (64 percent) was significantly lower than for white Americans (74 percent) and Hispanics (72 percent). Likewise, two-year survival was significantly lower for blacks (74 percent) and Asians (69 percent) than for whites (83 percent) and Hispanics (79 percent). The study appeared in the Jan. 26, 2002, issue of The Lancet.
"In terms of risk, African-Americans are 34 percent more likely to die from liver transplant than white Americans," says Thuluvath. "And Asians had an increased risk profile of 25 percent compared with white Americans."
Thuluvath and colleagues are now investigating claims that poor survival in blacks is due to such socioeconomic factors as poor compliance with postoperative care and lack of insurance benefits. Preliminary data on 500 liver transplant patients treated at Johns Hopkins suggests that socioeconomic factors are not at fault, and Thuluvath is analyzing more than 30,000 liver transplant cases in the UNOS registry to determine the extent to which socioeconomic factors can be implicated.
A diet rich in fruits, vegetables, and low-fat dairy products and limited in total and saturated fats, plus reduced dietary sodium, lowers blood pressure levels in all people, according to a new analysis of a government-sponsored study.
The diet also limits red meat, sweets, and sugar-containing drinks. It is rich in potassium, calcium, magnesium, fiber, and protein.
The Dietary Approaches to Stop Hypertension (DASH) study is supported by the National Heart, Lung, and Blood Institute (NHLBI).
Prior studies have found that besides blood pressure, the DASH diet lowers blood levels of low-density lipoprotein (LDL), the "bad" cholesterol, and the amino acid homocysteine, both of which may increase the risk of heart disease. Earlier research also has found that reducing dietary sodium alone lowers blood pressure.
The latest analysis showed that the DASH diet plus reduced dietary sodium lowers blood pressure in a wide variety of people, including those with and without hypertension or a family history of hypertension, older and younger adults, men and women, blacks and other races, and obese and non-obese individuals.
In addition, the combination lowered blood pressures in people with high or low physical activity levels, large or small waist circumferences, and high or low annual family incomes or education levels.
"This new study underscores the blood pressure-lowering effects of a reduced intake of salt and other forms of dietary sodium," says NHLBI Director Claude Lenfant, M.D. "Earlier research on the link between sodium and blood pressure had given conflicting results in various population groups. Now, we can say that cutting back on dietary sodium will benefit Americans generally and not just those with high blood pressure."
While the combination of the DASH diet and reduced dietary sodium produced the biggest reductions, each intervention also lowered blood pressure for all groups when used alone, according to the study, published in the Dec. 18, 2001, issue of the Annals of Internal Medicine.
"Adopting these measures could help millions of Americans avoid the rise in blood pressure that occurs with advancing age," says Frank Sacks, M.D., professor of cardiovascular disease prevention at the Harvard School of Public Health and chairman of the DASH steering committee.
The new data come from the DASH-Sodium study, a multicenter, 14-week randomized "feeding" trial in which all food was provided to participants. It involved 412 participants, ages 22 and older, and who had systolic blood pressures between 120 and 160 mm/Hg and diastolic blood pressures between 80 and 95 mm/Hg.
Fifty-two percent of the participants were women and 48 percent men. Forty-one percent had hypertension and 59 percent did not.
For three months, participants ate either the DASH diet or a typical American diet. Weight was kept stable. During the study period, each group followed three different intakes of dietary sodium for one month each in random order. The sodium levels were 3,300 milligrams a day (the average level consumed by Americans), 2,400 milligrams a day (the upper limit currently recommended by the National High Blood Pressure Education Program), and 1,500 milligrams a day.
The largest blood pressure differences occurred for those on the DASH diet with a daily sodium intake of 1,500 milligrams compared with those on the "typical" diet with a sodium intake of 3,300 milligrams.
Boys with chubby bellies are more likely to have high blood pressure than their slimmer counterparts, a new study indicates.
The study, which included 920 healthy children, did not find a similar association in girls. "To our knowledge, this study is the first to identify a gender difference in the association between fat distribution and blood pressure in children and adolescents," says the study's lead author, Dympna Gallagher, Ed.D., associate professor of nutrition at the Obesity Research Center, St. Luke's Roosevelt Hospital Institute of Human Nutrition in New York City.
Elevated blood pressure is associated with increased risk for developing high blood pressure as an adult. Other studies have shown that young adults who have high blood pressure develop left ventricular hypertrophy, or an enlarged heart, which can also increase the risk of having a heart attack early in life.
Researchers measured trunk fat distribution using skin-fold thickness and duel energy absorptiometry (DXA). DXA is a method for assessing bone mineral density and body composition. It involves scanning the body to distinguish fat and lean tissues.The study of children ages 5 to 18 included 442 girls (145 black, 161 Asian, and 136 Caucasian) and 478 boys (128 black, 184 Asian, and 166 Caucasian).
"Trunk fat by skin fold and DXA measurement was positively associated with systolic and diastolic pressure," says Gallagher. "However, when we looked at the gender groups separately, we found the relationship was limited to boys and this difference was not influenced by race."
In adults, a greater accumulation of trunk fat is known to be a predisposing factor for increased cardiovascular risk. Gallagher adds that children with a similar fat distribution may be at increased risk.
The study, titled "Trunk Fat and Blood Pressure in Children through Puberty," is published in the Feb. 4, 2002, rapid access issue of Circulation: Journal of the American Heart Association. For more information, visit the American Heart Association journals home page at www.ahajournals.org, click on the Circulation icon, then click on the Rapid Access Publications button.
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