Sex-specific relation of replacing sedentary time with physical activity on stage 2 hypertension incidence in...

Hypertension is increasingly prevalent among middle-aged adults, but the impacts of physical activity and postures are not fully understood in middle-aged males and females, limiting targeted prevention. This study investigated associations between habitual physical activity and postures with hypertension, and whether they differ between sexes at the same age. 4416 participants (age: 46 years) in the 10th sweep of the 1970 British Cohort Study were used. Participants wore an activPAL to measure physical behaviors. Stage 2 hypertension was defined as >140/90 mmHg or antihypertensive medication use. Isotemporal substitution models assessed the theoretical effect of reallocating 30 min of one behavior with another. Males had higher mean body mass index (BMI: 28.5 ± 4.6 kg/m² vs. 27.9 ± 6.0), systolic (129.1 ± 13.3 mmHg vs. 119.6 ± 14.7 mmHg) and diastolic blood pressure (79.0 ± 10.4 vs. 74.8 ± 10.7 mmHg) compared to females (all, p < 0.001). In pooled analyses, substituting sedentary time with light physical activity (LPA) (OR = 0.93 [0.86, 0.998]) or moderate-to-vigorous physical activity (MVPA) (OR = 0.90 [0.83, 0.97]) was associated with lower odds of hypertension. In males, replacing sedentary time or standing with any activity reduced hypertension risk (ORs 0.86-0.88), whereas in females, only replacing sedentary time with standing was associated with lower risk (OR = 1.04 [1.01, 1.07]). MVPA demonstrated stronger associations than LPA. Replacing sedentary or standing behaviors with movement, particularly MVPA, may reduce hypertension risk in middle-aged adults, with more pronounced benefits observed in males. These findings support the development of sex-specific interventions targeting physical activity behavior patterns to mitigate hypertension risk during midlife.