Background: Although lifestyle modifications generally are effective in lowering blood pressure (BP) among patients with unmedicated hypertension and in those treated with 1 or 2 antihypertensive agents, the value of exercise and diet for lowering BP in patients with resistant hypertension is unknown.
Methods: One hundred forty patients with resistant hypertension (mean age, 63 years; 48% female; 59% Black; 31% with diabetes; 21% with chronic kidney disease) were randomly assigned to a 4-month program of lifestyle modification (C-LIFE [Center-Based Lifestyle Intervention]) including dietary counseling, behavioral weight management, and exercise, or a single counseling session providing SEPA (Standardized Education and Physician Advice). The primary end point was clinic systolic BP; secondary end points included 24-hour ambulatory BP and select cardiovascular disease biomarkers including baroreflex sensitivity to quantify the influence of the baroreflex on heart rate, high-frequency heart rate variability to assess vagally mediated modulation of heart rate, flow-mediated dilation to evaluate endothelial function, pulse wave velocity to assess arterial stiffness, and left ventricular mass to characterize left ventricular structure.
Results: Between-group comparisons revealed that the reduction in clinic systolic BP was greater in C-LIFE (-12.5 [95% CI, -14.9 to -10.2] mm Hg) compared with SEPA(-7.1 [-95% CI, 10.4 to -3.7] mm Hg) (P=0.005); 24-hour ambulatory systolic BP also was reduced in C-LIFE (-7.0 [95% CI, -8.5 to -4.0] mm Hg), with no change in SEPA (-0.3 [95% CI, -4.0 to 3.4] mm Hg) (P=0.001). Compared with SEPA, C-LIFE resulted in greater improvements in resting baroreflex sensitivity (2.3 ms/mm Hg [95% CI, 1.3 to 3.3] versus -1.1 ms/mm Hg [95% CI, -2.5 to 0.3]; P<0.001), high-frequency heart rate variability (0.4 ln ms2 [95% CI, 0.2 to 0.6] versus -0.2 ln ms2 [95% CI, -0.5 to 0.1]; P<0.001), and flow-mediated dilation (0.3% [95% CI, -0.3 to 1.0] versus -1.4% [95% CI, -2.5 to -0.3]; P=0.022). There were no between-group differences in pulse wave velocity (P=0.958) or left ventricular mass (P=0.596).
Conclusions: Diet and exercise can lower BP in patients with resistant hypertension. A 4-month structured program of diet and exercise as adjunctive therapy delivered in a cardiac rehabilitation setting results in significant reductions in clinic and ambulatory BP and improvement in selected cardiovascular disease biomarkers. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02342808.
Keywords: DASH diet; cardiac rehabilitation; exercise; hypertension; lifestyle.