Comparison of single versus multiple lifestyle interventions: Are the antihypertensive effects of exercise training and diet-induced weight loss additive?

Although aerobic exercise training and diet-induced weight loss each have been shown to individually lower elevated blood pressure (BP), it is currently not known whether their combined use produces an additive antihypertensive effect. In this randomized clinical trial we therefore compared the effect on resting BP of exercise training only and dietary modification only with that of exercise training plus dietary modification in 55 sedentary, overweight patients with high normal BP or stage 1 or 2 hypertension. After baseline testing, patients were randomized to 1 of the following 3 interventions for 12 weeks: exercise training only (aerobic exercise; 30 to 45 minutes; 3 to 5 days/week; 60% to 85% of maximal heart rate), dietary modification only (aimed primarily at weight loss via restriction of energy intake and dietary fat), or exercise training plus dietary modification. Forty-eight patients completed the study. In these patients, exercise training plus dietary modification elicited a greater reduction (p ≤0.001) in body weight (-7.1 ± 2.9 vs -1.0 ± 1.8 kg) than exercise training only, and a greater increase (p ≤0.05) in maximal oxygen uptake (4.3 ± 2.6 vs 1.9 ± 2.0 ml/kg/min) versus dietary modification only. However, the reduction in BP with exercise training plus dietary modification (-12.5 ± 6.3/7.9 ± 4.3 mm Hg) did not differ significantly from that with exercise training only (-9.9 ± 6.4/5.9 ± 4.6 mm Hg) or dietary modification only (-11.3 ± 12.1/7.5 ± 4.3 mm Hg). These data indicate that the antihypertensive effects of exercise training and diet-induced weight loss are not additive. This finding has important public health and clinical implications for the millions of overweight parsons with high normal BP or stage 1 or 2 hypertension.