The long-term effects of lifestyle change on blood pressure: One-year follow-up of the ENCORE study

Abstract

Background: There is a paucity of data describing the sustained benefits of lifestyle interventions on health behaviors and blood pressure (BP).

Methods: We examined the persistence of changes in health habits and BP in the ENCORE study, a trial in which 144 overweight individuals with above-normal BP were randomized to one of the following 16-week interventions: Dietary Approaches to Stop Hypertension (DASH) diet alone (DASH-A), DASH diet plus a behavioral weight management intervention (DASH-WM), or Usual Care. Follow-up assessments were conducted 8 months after the end of treatment.

Results: At 16 weeks, systolic BP was reduced by 16.1 (95% confidence interval (CI) = 13.0-19.2) mm Hg in the DASH-WM group, 11.2 (95% CI = 8.1-14.3) mm Hg in the DASH-A group, and 3.4 (95% CI = 0.4-6.4) mm Hg in the Usual Care group. A decrease in BP persisted for 8 months, with systolic BP lower than baseline by 11.7 (95% CI = 8.1-15.3) mm Hg in the DASH-WM group, 9.5 (95% CI = 6.7-12.1) mm Hg in the DASH-A group, and 3.9 (95% CI = 0.5-7.3) mm Hg in the Usual Care group (P < 0.001 for active treatments vs. Usual Care). DASH-WM subjects lost 8.7 kg during the intervention and remained 6.3 kg lighter on follow-up examination. Changes in diet content were sustained in both DASH intervention groups. Among those who participated in DASH-WM, however, caloric intake was no longer lower, and only 21% reported still exercising regularly 8 months after completing the intervention.

Conclusions: Changes in dietary habits, weight, and BP persisted for 8 months after completion of the 16-week ENCORE program, with some attenuation of the benefits. Additional research is needed to identify effective methods to promote long-term maintenance of the benefits of lifestyle modification programs.

Clinical trial registration: Clinicaltrials.gov identifier: NCT00571844.

Keywords: DASH diet; blood pressure; exercise; hypertension.

Figures

Figure 1.

Patient flow from initial screening to 1-year follow-up. Abbreviations: DASH-A, Dietary Approaches to Stop Hypertension (DASH) diet alone; DASH-WM, DASH diet plus behavioral weight management.

Figure 2.

Mean weight in kilograms for each treatment group before and after 16 weeks of treatment and 1 year after study entry. Baseline values are adjusted for age, race, and sex. Values for 4 and 12 months are derived from the mixed model and are adjusted for age, race, sex, and baseline body weight. Error bars represent 95% confidence intervals. The narrow confidence intervals for the 4 and 12 month values reflect the adjustment of these values for baseline body weight. Abbreviations: DASH-A, Dietary Approaches to Stop Hypertension (DASH) diet alone; DASH-WM, DASH diet plus behavioral weight management.

Figure 3.

Mean (a) systolic and (b) diastolic BP for each treatment group before and after 16 weeks of treatment and 1 year after study entry. Baseline values are adjusted for age, race, and sex. Values for 4 and 12 months are derived from the mixed model and are adjusted for age, race, sex, baseline body weight, and baseline BP. Error bars represent 95% confidence intervals. Abbreviations: BP, blood pressure; DASH-A, Dietary Approaches to Stop Hypertension (DASH) diet alone; DASH-WM, DASH diet plus behavioral weight management.