Lifestyle interventions reduce coronary heart disease risk: results from the PREMIER Trial

Abstract

Background: Although trials of lifestyle interventions generally focus on cardiovascular disease risk factors rather than hard clinical outcomes, 10-year coronary heart disease (CHD) risk can be estimated from the Framingham risk equations. Our objectives were to study the effect of 2 multicomponent lifestyle interventions on estimated CHD risk relative to advice alone and to evaluate whether differences can be observed in the effects of the lifestyle interventions among subgroups defined by baseline variables.

Methods and results: A total of 810 healthy adults with untreated prehypertension or stage I hypertension were randomized to 1 of 3 intervention groups: An "advice-only" group, an "established" group that used established lifestyle recommendations for blood pressure control (sodium reduction, weight loss, and increased physical activity), or an "established-plus-DASH" group that combined established lifestyle recommendations with the DASH (Dietary Approaches to Stop Hypertension) diet. The primary outcome was 10-year CHD risk, estimated from follow-up data collected at 6 months. A secondary outcome was 10-year CHD risk at 18 months. Of the 810 participants, 62% were women and 34% were black. Mean age was 50 years, mean systolic/diastolic blood pressure was 135/85 mm Hg, and median baseline Framingham risk was 1.9%. The relative risk ratio comparing 6-month to baseline Framingham risk was 0.86 (95% confidence interval 0.81 to 0.91, P<0.001) in the established group and 0.88 (95% confidence interval 0.83 to 0.94, P<0.001) in the established-plus-DASH group relative to advice alone. Results were virtually identical in sensitivity analyses, in each major subgroup, and at 18 months.

Conclusions: The observed reductions of 12% to 14% in estimated CHD risk are substantial and, if achieved, should have important public health benefits.

Figure 1

Flow of Participants in the PREMIER Trial *Number of participants with complete covariates for Framingham risk equations. Abbreviations: EST, established; EST+DASH, established + DASH; DASH, Dietary Approaches to Stop Hypertension; BP, blood pressure; CHD Risk, 10-year coronary heart disease risk.

Figure 2

Median 10-Year CHD Risk in the PREMIER Trial by Randomized Group at Baseline and 6 Months Note: 10-year CHD risk refers to the estimated risk of CHD in the next 10 years; for example, a 10-year CHD risk of 1.5% indicates an estimated risk of 1.5% of CHD in the next 10 years. Abbreviations: CHD, coronary heart disease risk; EST, established; EST+DASH, established + DASH; DASH, Dietary Approaches to Stop Hypertension; RRR, relative risk ratio.