Blood pressure responses to lifestyle physical activity among young, hypertension-prone African-American women

Abstract

Background: Physical inactivity and obesity increase the risk for hypertension, and both are more prevalent in African-American than Caucasian women. Regular physical activity serves as an important intervention for reducing cardiovascular risk, yet the ideal physical activity profile to meet the needs of young, sedentary African-American women remains unclear. We performed a randomized, parallel, single-blind study to examine the effect of lifestyle physical activity (LPA) on blood pressure indices in sedentary African-American women aged 18 to 45 years with prehypertension or untreated stage 1 hypertension.

Methods: The primary intervention was an 8-week individualized, home-based program in which women randomized to Exercise (n = 14) were instructed to engage in lifestyle-compatible physical activity (eg, walking, stair climbing) for 10 minutes, 3 times a day, 5 days a week, at a prescribed heart rate corresponding to an intensity of 50% to 60% heart rate reserve. Women in the No Exercise group (n = 10) continued with their usual daily activities. Mean changes in cuff, ambulatory, and pressure load indices were compared using paired t tests, and physical activity adherence was expressed as percentages.

Results: Women in the Exercise group had a significant reduction in systolic blood pressure (-6.4 mm Hg, P = .036), a decrease in diastolic blood pressure status to the prehypertensive level (90.8 vs 87.4 mm Hg), and greater reductions in nighttime pressure load compared with the No Exercise group. Adherence to LPA was exceedingly high by all measures (65%-98%) and correlated with change in systolic blood pressure (r = -0.620, P = .024).

Conclusion: The accumulation of LPA reduced cuff, ambulatory, and pressure load. The accumulation of LPA appears well tolerated and feasible in this sample of young African-American women, demonstrated by the overall high adherence rates. Given the excess burden of pressure-related clinical sequelae among African Americans and the strong correlation between pressure load and target organ damage, LPA may represent a practical and effective strategy in this population.