Abstract MP041: Time Course of Change in Blood Pressure From the DASH Diet and Sodium Reduction
Background: The time course of change in BP from lifestyle interventions, particularly sodium reduction, is uncertain.
Hypotheses: (1) The DASH diet and sodium reduction will lower BP rapidly (within 1 wk), and (2) BP effects will be sustained over time.
Methods: In the DASH-Sodium trial, adults without cardiovascular disease, not using antihypertensive medications, were randomly assigned to either a control diet or the DASH diet. With either diet, participants were fed each of three sodium levels in random order in 4-wk periods separated by 5-day breaks. The three sodium levels were: low (50 mmol/d), medium (100 mmol/d), and high (150 mmol/d). BP was measured during the run-in period and weekly over 12 wks of the trial. Differences in BP were determined at the end of each wk. Trends in differences were modeled via linear regression.
Results: The trial enrolled 412 participants (57% women, 57% black, mean age was 48 yrs, mean SBP/DBP was 135/86 mmHg). Compared with the control diet, DASH lowered SBP at wk 1 (-4.36; -6.96,-1.77) and wk 12 (-3.82; -6.03,-1.61); corresponding changes in DBP were -1.07 (-2.66, 0.53) and -0.99 (-2.32, 0.33) (Figure). From wk 1 to 12, there was no trend in the difference between DASH and control diets for either SBP (P-trend = 0.91) or DBP (P-trend = 0.99). In the context of the control diet, reducing sodium from high to low, changed SBP by -4.03 (-6.66,-1.39) and DBP by -0.80 (-2.50, 0.89) after 1 wk, and SBP by -6.66 (-8.84,-4.47) and DBP by -3.43 (-4.72,-2.13) after 4 wks. Trends in differences from wk 1 to 4 were significant for SBP (P-trend = 0.02) and non-significant for DBP (P-trend = 0.1). There was no trend over time in SBP or DBP from reducing sodium while on the DASH diet (P-trend for SBP = 0.71 and for DBP = 0.25).
Conclusions: The DASH diet lowers SBP and DBP early and its effects were maintained with dietary adherence over time. Meanwhile, the effects of sodium reduction on SBP were not fully realized by 4 wks in the context of a typical American diet, suggesting that the effect of lowering sodium on SBP continues to increase over time.
Author Disclosures: S.P. Juraschek: C. Other Research Support; Significant; T32 Renal Disease Epidemiology Training Grant. M. Woodward: None. F.M. Sacks: None. V.J. Carey: None. E.R. Miller: None. L.J. Appel: None.
- © 2017 by American Heart Association, Inc.