Role of the Intensity of Habitual Physical Activity in the Maintenance of Normal Blood Pressure: Findings From the SUN Longitudinal Cohort Study

BACKGROUND: Physical activity (PA) is known to protect against incident hypertension, but the preferred intensity of PA to prevent hypertension remains unknown. Energy expenditure (EE) in PA is generally considered the primary determinant of effect, whereas intensity is usually considered nondifferential provided it is moderate or above. However, intensity may produce its own distinct effect. METHODS AND RESULTS: We used data from the SUN (Seguimiento Universidad de Navarra) cohort—a large prospective longitudinal cohort in Spain—to investigate the relation between intensity of habitual PA and hypertension incidence. Average intensity of habitual PA was calculated including both leisure time PA and incidental PA (walking and stairclimbing). Hazard ratios (HRs) for incident hypertension and 95% CIs were estimated using Cox regression analyses adjusted for EE, body mass index, and other important covariables. Comparative models explored how duration of time in PA and EE in PA related to hypertension incidence. In the study,10 524 participants without prior diagnosis of hypertension (62.5% women, mean age 36.2 years, mean body mass index 23.3 kg/m2) were followed for 126 876 person-years. A total of 1504 cases of incident hypertension emerged. After adjustment for EE and other covariables, increasing intensity of PA was monotonically associated with decreased risk for incident hypertension (adjusted HR for Q5 versus Q1, 0.77 [95% CI, 0.64–0.92]). In contrast, increasing time in PA did not appear to affect risk of incident hypertension following adjustment for EE (aHR for Q5 versus Q1, 0.94 [95% CI, 0.57–1.55]). CONCLUSIONS: Intensity of habitual PA is independently and inversely associated with incidence of hypertension.