DASH diet, sodium reduction improve BP levels, but not BPV

Both the Dietary Approaches to Stop Hypertension (DASH) diet and sodium intake reduction are effective in lowering absolute blood pressure (BP) levels, but these interventions do not yield significant benefits in BP variability (BPV), reports a study.

Using both office and 24-h ambulatory BP measurements in the DASH and DASH-Sodium trials, the investigators assessed the effects of dietary patterns (DASH vs control) and sodium intake (higher vs lower) on BPV in this study.

Week-to-week office BPV and 24-h ambulatory BPV were quantified in primary analyses using variation independent of the mean (VIM). The investigators also performed between-group comparisons using t-tests and explored the interactive effects between dietary patterns and sodium intake using multivariate linear regression models.

Pooled analyses revealed no significant difference in week-to-week systolic BPV (difference in systolic VIM, 0.49, 95 percent confidence interval [CI], ‒0.05 to 1.03) or 24-h systolic BPV (difference in systolic VIM, 0.37, 95 percent CI, ‒0.13 to 0.87) between the DASH and control diet groups.

In the DASH-Sodium trial, no difference was observed between VIM at higher and lower sodium levels (eg, difference in VIM for week-to-week systolic BP, 0.31, 95 percent CI, ‒0.10 to 0.72). Likewise, there was no significant combined or interactive effects of diet and sodium seen on BPV.

“These findings suggest that the BP-related benefits of the DASH diet and sodium reduction likely result from reducing absolute BP rather than reducing BPV,” the investigators said.