Physical Activity, Sedentary Time, and Cardiovascular Disease Biomarkers at Age 60 to 64 Years.

Abstract

ABSTRACT Background We examined associations of objectively-measured physical activity (PA) and sedentary time with cardiovascular disease (CVD) biomarkers at age 60-64. This included investigation of sex differences and the extent to which associations may be mediated by adiposity. Methods and Results Participants were 795 men and 827 women aged 60-64 years from the MRC National Survey of Health and Development. Combined heart rate and movement sensors worn for 5 consecutive days were used to derive overall PA energy expenditure (PAEE, kJ/kg/day) and time spent sedentary (<1.5 METs), in light (LPA, 1.5–3 METs) and moderate-to-vigorous intensity PA (MVPA, >3 METs). Linear regression models were used to relate each PA parameter to inflammatory (CRP, IL-6), endothelial (t-PA, E-selectin) and adipokine (leptin, adiponectin) markers extracted from fasting blood samples. Greater time in LPA and MVPA and less sedentary time were associated with more favourable biomarker levels. For CRP, IL-6 and leptin, these differences were greater among women than men. For example, % differences (95% confidence intervals) in leptin for men and women per standard deviation increases in sedentary time: 7.9 (2.7, 13.0) and 20.6 (15.3, 25.8); LPA: -3.8 (-8.9, 12.7) and -17.7 (-23.1, -12.4), MVPA: -12.9 (-17.9, -8.0) and -18.3 (-23.4, -13.1). Fat mass mediated a greater proportion of these associations in women than men. Conclusions Greater LPA and MVPA and less sedentary time in early old age were associated with more favourable cardiovascular biomarker profiles. Fat mass partially mediated these associations but more strongly in women than men which explained sex differences.