Patterns of sedentary time and cardiometabolic risk among Canadian adults.

OBJECTIVE The aim of this study is to examine the associations of total sedentary time and patterns of sedentary time with cardiometabolic biomarkers in a large representative sample of Canadian adults. METHODS The study is based on 4935 adults aged 20-79years, from the 2007/09 and 2009/11 Canadian Health Measures Survey. Total sedentary time, patterns of sedentary time (≥20minute prolonged sedentary bouts, number of sedentary breaks), and moderate- to vigorous-intensity physical activity (MVPA) were accelerometer-derived. Waist circumference, systolic and diastolic blood pressure, high-density lipoprotein (HDL) cholesterol, and C-reactive protein were measured. Triglycerides, low-density lipoprotein (LDL) cholesterol, insulin, and glucose were also measured in a fasting sub-sample (n=2551). RESULTS Total sedentary time and time in ≥20minute prolonged sedentary bouts were associated with higher insulin and lower diastolic blood pressure levels (P<0.05). On average, each additional 10 breaks/day was associated with 0.83 (95%CI: 1.35, 0.31) cm lower waist circumference, 0.32 (0.62, 0.02) mmHg lower systolic blood pressure, 0.01 (0.00, 0.02) mmol/l higher HDL-cholesterol, 3.72 (1.34, 6.13) % lower triglycerides, 0.57 (0.23, 0.92) % lower glucose, and 4.19 (1.80, 6.63) % lower insulin. CONCLUSION These findings in a large representative sample of Canadian adults indicate that breaking up sedentary time may be particularly important for cardiometabolic health.