Time Spent Sitting as an Independent Risk Factor for Cardiovascular Disease

Sedentary behavior is highly prevalent despite growing evidence of adverse effects on the cardiovascular and metabolic system that are independent of the level of recreational physical activity (PA). We present results for the association between sitting time and cardiovascular disease (CVD) from selected cohort and cross-sectional studies published in or after the year 2010 according to the domains where sitting time is accumulated during the day. These include TV viewing, occupational sitting, and sitting during transportation as well as overall sitting. The outcomes considered in this review are total CVD, coronary heart disease, and stroke as well as CVD risk factors-namely, hypertension, hypercholesterolemia, and type 2 diabetes and their associated biomarkers. Finally, several current issues with regard to studying the effects of sitting time on CVD are discussed, including how sedentary behavior is assessed, isotemporal substitution modeling, examination of joint associations for sitting and PA, and benefits of breaks in sitting time. Overall, the scientific evidence supports public health recommendations that encourage adults to limit their sedentary time in order to improve their cardiovascular health.