Effects of individual components of multiple behavior changes: the PREMIER trial.

Objectives: To assess contributions of individual lifestyle changes on systolic blood pressure (SBP) changes.

Methods: We examined associations between lifestyle behavior changes and SBP after 6 and 18 months in 782 PREMIER trial participants.

Results: In multivariate models omitting weight, predicted SBP reductions ranged from (1)/2 to 1(1)/2 mm Hg for reduced urinary sodium, improved fitness, and adherence to the DASH diet (except sodium at 18 months). With weight included, only fitness change additionally predicted SBP at 18 months.

Conclusions: Several lifestyle behavior changes are important for BP lowering, but are difficult to detect when weight is included in multivariate models.