1.a.(1). Lifestyle Trials in Hypertensive Patients

Rationale: A1987 meta-analysis (381) covering five of the acceptable studies (351, 352, 356-358) in hypertensive patients concluded that weight loss accomplished by dietary interventions significantly lowered blood pressure. In hypertensive patients, 10 kg (22 lb) of weight loss was associated with an average reduction of 7 mm Hg systolic and 3 mm Hg diastolic blood pressure compared with controls (381).

Since publication of this meta-analysis in 1987, almost all relevant studies have reported that weight loss reduces blood pressure or the need for medication in hypertensive patients (346-348, 350, 352-361):

• The Trial of Antihypertensive Interventions and Management (TAIM), conducted in hypertensive individuals not taking medication for 6 months, reported that, compared with controls, a mean net weight reduction of 4.7 kg (10.4 lb) reduced systolic and diastolic blood pressure by 2.8 mm Hg and 2.5 mm Hg, respectively (355); the effects on blood pressure were equivalent to drug therapy among those participants who lost 4.5 kg (9.9 lb) or more (360). 
• One study in older (age 60 to 80 years) hypertensive adults whose blood pressure medication was withdrawn (Trial of Nonpharmacologic Interventions in the Elderly, TONE) showed that after 2 years, mean net weight loss of nearly 4 kg (9 lb) resulted in more participants free of trial endpoints (occurrence of high blood pressure, resumption of blood pressure medication, or occurrence of a cardiovascular-clinical complication [39.2 percent versus 26.2 percent]) (382). Furthermore, blood pressure control was similar for men and women and for African Americans and whites (353). 
• In other studies of primarily middle-aged hypertensive adults, compared with controls, weight loss significantly reduced a return to hypertension medication at 1 year (354) and at 4 to 5 years (348, 359). 
• The Multiple Risk Factor Intervention Trial, which recruited 12,866 high risk men, 30 percent of whom had hypertension, delivered an integrated intervention addressing several lifestyle behaviors and included weight loss as an important component. Significant reductions in systolic and diastolic blood pressure were found over 6 years compared with the usual care group and were directly related to weight loss: 1 kg (2.2 lb) of weight loss was associated with a reduction of 0.4 mm Hg systolic and 0.3 mm Hg diastolic blood pressure in men not taking antihypertensive medications. The effect was slightly lower for men taking antihypertensive medications. 
• Only one RCT conducted in hypertensive patients reported no significant change in blood pressure despite weight loss of 3.3 kg (7.3 lb) (351).
• Another study conducted in hypertensive individuals suggested that weight loss reduced blood pressure only when sodium intake was also reduced (349).This finding was not consistent with a prior study of hypertensive patients (358) and has not been corroborated in subsequent larger trials conducted in nonhypertensive individuals (378, 379).