Does exercise decrease blood pressure in healthy postmenopausal women?
In this meta-analysis, a bunch of crummy little studies found that exercise lowers blood pressure by a very small and clinically insignificant degree in healthy postmenopausal women with normal or high-normal blood pressure.
Meta-analysis (randomized controlled trials)
These authors searched several databases and registries to identify randomized trials that included healthy postmenopausal women with normal or high-normal blood pressure. The studies had to include at least 4 weeks of exercise of at least 30 minutes per session at least twice a week. The authors included 12 studies with 687 participants. The overall methodologic quality was poor to mediocre, with the greatest problems related to protocol deviations and the randomization process. The authors identified many differences in how blood pressure was measured: automated, manual, unlisted; supine, sitting. After pooling the data, the authors report that exercise resulted in a net 0.43 mm Hg lowering of systolic blood pressure (95% CI −0.78 to −0.09) and 0.39 mm Hg lowering of diastolic pressure (−0.73 to −0.05). These data were moderately heterogeneous across the studies. When the authors excluded the studies that used resistance exercise or those that included women with normal blood pressure, the net effects on systolic blood pressure, but not diastolic pressure, were trivially greater than the magnitude seen in the full pool of studies. The authors found no evidence for publication bias. A major limitation in reporting average blood pressure changes is the potential for missing participants who experience large and clinically meaningful blood pressure reductions.
Henry C. Barry, MD, MS
Michigan State University
East Lansing, MI