Abstract
OBJECTIVE: Physical activity (PA) is generally cardioprotective, but the relationship between PA intensity and bout length and major adverse cardiovascular events (MACEs) in adults with hypertension remains unclear.
METHODS: Participants of the UK Biobank wearables substudy with a clinical diagnosis of hypertension were included. Short bouts of moderate intensity PA were classified as lasting up to 3 min and for vigorous intensity up to 1 min. Long bouts of moderate intensity PA were classified as lasting >5 min and for vigorous intensity >2 min. MACEs were defined as the composite of cardiovascular disease mortality and incidence of stroke, myocardial infarction and heart failure. We used Cox proportional hazards regression and Fine-Gray subdistribution for MACE and subtype analyses.
RESULTS: During an average follow-up of 7.9 (±1.1) years among 38 960 participants (58.1% female; average age 62.1 (±7.7) years), there were 1416 MACE, including 397 stroke, 508 myocardial infarction and 363 heart failure events. Both short and long bouts of moderate intensity PA were associated with lower MACE risk, with subtype analyses showing longer bouts may enhance protective associations. For vigorous intensity PA, amounts accrued through short bouts exhibited a consistent association with lower MACE risk (HR=0.62 (95% CI 0.51 to 0.76) for 22 min/week), while amounts accrued through long bouts were associated with a higher risk of stroke, with a steep gradient of higher risk with longer durations (HR=2.06 (95% CI 1.38 to 3.07) for 44 min/week up to 2.80 (95% CI 1.72 to 4.56) for 64 min/week).
CONCLUSIONS: Short and long bouts of moderate intensity PA were associated with a lower risk of overall MACE, with evidence suggesting that longer bouts may enhance this protective association. For vigorous intensity PA, short bouts showed strong associations with lower overall MACE risk, while long bouts were associated with a 2-3 fold higher stroke risk, with a dose-response pattern evident across higher durations. Our results highlight the benefits and risks of PA bout length and intensity in adults with hypertension.