Abstract 1153: The Effect of Dietary Patterns on Estimated Coronary Heart Disease Risk: Results From the Dietary Approaches to Stop Hypertension Trial
Background In lifestyle intervention trials, the primary outcomes are typically risk factors, not clinical outcomes. In the Dietary Approaches to Stop Hypertension (DASH) trial, the DASH dietary pattern decreased blood pressure relative to control and also decreased LDL and HDL cholesterol.
Objective To evaluate the effect of dietary patterns on estimated 10-year coronary heart disease (CHD) risk taking into account both changes in blood pressure and serum lipids.
Methods DASH was a multi-center, randomized trial in which 459 individuals with pre- or stage-1 hypertension not on antihypertensive medication were randomized to one of three dietary patterns: control, fruits and vegetables (F/V), and DASH (rich in fruits and vegetables and low in total and saturated fat). We used linear regression to obtain a relative risk ratio (RRR) comparing the effects of the dietary patterns on estimated 10-year CHD risk at 8 weeks to baseline using the Framingham risk equations overall and across subgroups defined by baseline risk.
Results Among the 436 participants with complete data, mean (SD) age was 44.7 (10.7) years, mean (SD) BMI was 28.2 (3.9) kg/m2, 224 (51%) were male, and 260 (60%) were black. Median estimated 10-year CHD risk was 0.98% at baseline and decreased in all groups at 8 weeks. Compared with control, the RRR comparing 8-week to baseline 10-year CHD risk was 0.93 (95% CI: 0.85–1.02, P=0.12) for F/V and 0.82 (95% CI: 0.75– 0.90, P<0.001) for DASH. Comparing DASH to F/V, this RRR was 0.89 (95% CI: 0.81– 0.97, P=0.012). Results were similar across subgroups of gender, baseline estimated 10-year CHD risk, hypertension status, baseline serum total cholesterol, and age; there was an interaction between the intervention dietary patterns and race (P for interaction=0.038), such that blacks experienced greater benefit than whites.
Conclusions Compared to control and F/V, DASH decreased estimated 10-year CHD risk by 18% and 11%, respectively. In addition to reducing BP, the DASH dietary pattern should substantially reduce the risk of CHD and potentially reduce racial disparities in BP-related CVD.