Physical Activity Intervention In Reducing Blood Pressure Between Sexes In Sedentary Adults

PURPOSE: Increases in physical activity (PA) are associated with improved blood pressure (BP) outcomes, but only ~10% of U.S. adults meet PA guidelines. Further, sex differences in BP responses to a PA intervention in sedentary adults have not been reported. Thus, we examined sex differences in BP responses to a one-year PA intervention in sedentary adults. METHODS: Sedentary males (n = 132) and females (n = 221), underwent BP assessments at baseline and after a yearlong PA intervention. Baseline age, BMI, SBP, DBP, RHR, and smoking history were compared between sexes using independent T-tests and chi-squared analyses. Mixed model analyses were used with sex (male vs. female) and time (pre- vs. post-intervention) as main effects and sex by time interactions were used to compare changes in systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), and resting heart rate (RHR) between sexes. Associations between change in moderate to vigorous PA (MVPA) and hemodynamic measures were examined using Pearson correlations. Data are presented as means ± SD; α was set at 0.05. RESULTS: Data were analyzed and age (M = 44 ± 9, F = 46 ± 9), BMI (M = 34.1 ± 6.2, F = 32.4 ± 6.9), baseline SBP (M = 125 ± 12, F = 118 ± 13), RHR (M = 68 ± 11, F = 68 ± 10), and smoking status (M = 8, F = 9) were not different between sexes. Baseline DBP (M = 83 ± 9, F = 79 ± 11, p = 0.025) was significantly different between sexes. We observed a trend for reduction of SBP following the intervention in females vs. males (Females: Pre = 118 ± 13, Post = 116 ± 13 mmHg, Males: Pre = 125 ± 12, Post = 126 ± 12 mmHg, p = 0.057). No sex differences were observed in MAP (Males: Pre = 97 ± 9, Post = 97 ± 10 mmHg vs Females: Pre = 92 ± 11, Post = 90 ± 10 mmHg, p = 0.14), or RHR (Males: Pre = 68 ± 11, Post = 68 ± 10 vs Females: Pre = 69 ± 10, Post = 67 ± 10, p = 0.52) or in baseline adjusted DBP (Males: Pre = 82 ± 9, Post = 83 ± 9 mmHg vs Females: Pre = 80 ± 11, Post = 77 ± 10 mmHg, p = 0.23). Change in SBP was not correlated with change in MVPA in males (r = -0.047) or females (r = 0.083). CONCLUSION: Males and females had divergent SBP responses to a one-year, walking-based PA intervention that trended towards significance. No significant interactions were observed for DBP, MAP, RHR, and MVPA. These findings suggest that sex differences in SBP response to a PA intervention are probable and may warrant further investigation. Supported by R01CA198915