Impact of Hypertension on the Dose-Response Association Between Physical Activity and Stroke: A Cohort Study.

ABSTRACT

BACKGROUND: Regular physical activity is associated with a reduced stroke risk. However, this relationship might be attenuated in the presence of hypertension and antihypertensive medication use. We examined the dose-response relationship between physical activity and stroke in normotensive and hypertensive individuals. METHODS: A Dutch population-based cohort including 139 930 individuals (41% men; mean age, 44±13) was performed (median follow-up, 6.75 years). Participants were stratified at baseline as hypertensive (44%) or normotensive (56%) and categorized into quartiles of the lowest (Q1) to the highest (Q4) moderate-to-vigorous, self-reported physical activity. The primary outcome was incident stroke (fatal and nonfatal). Cox regression estimated hazard ratios and 95% CIs. The main analyses were stratified on baseline blood pressure and adjusted for confounders. Hypertensives were stratified into medicated (21%) or non-medicated (79%). RESULTS: Compared with Q1, adjusted hazard ratios were 0.87 (0.69-1.10; P=0.23), 0.75 (0.59-0.95; P=0.02), and 0.94 (0.74-1.20; P=0.64) for Q2 to Q4, respectively in the total population. Hazard ratios for normotensives were 0.79 (0.50-1.25; P=0.32), 0.75 (0.48-1.18; P=0.22), 0.97 (0.62-1.51; P=0.90) for Q2 to Q4, respectively. In hypertensives, hazard ratios were 0.89 (0.68-1.17; P=0.41), 0.74 (0.56-0.98; P=0.03), 0.92 (0.69-1.23; P=0.56) for Q2 to Q4, respectively. There was no significant interaction between hypertension status for the relation between physical activity and stroke risk. The stratified analysis revealed a smaller benefit of moderate-to-vigorous physical activity in medicated hypertensives compared with nonmedicated hypertensives, but no significant interaction effect was found. CONCLUSIONS: Regular moderate-to-vigorous physical activity is beneficial for stroke risk reduction (Q3 compared with Q1), which is not affected by hypertension. Antihypertensive medication may be associated with a smaller benefit of moderate-to-vigorous physical activity on the risk of stroke, but further research is warranted.