Leisure-time physical activity does not attenuate the association between occupational sedentary behaviour and obesity: Results from the Tomorrow Project in Alberta, Canada.
Journal: J.Phys.Act.Health | Date: April 2015 | Authors: Nicholas JA, Lo Siou G, Lynch BM, Robson PJ, Friedenreich CM, Csizmadi I.
BACKGROUND:
Sedentary behaviour has been proposed as a risk factor for obesity that is distinct from physical inactivity. This study aimed to examine the association between occupational sedentary behaviour and obesity, and to determine if this association is independent of leisure-time physical activity (LTPA).
METHODS:
Fully-employed participants enrolled between 2001 and 2008 to the Tomorrow Project, a prospective cohort study in Alberta, Canada, were studied (n=12,409). Associations between occupational sedentary behaviour and waist circumference (WC), waist-to-hip ratio (WHR), and body mass index (BMI) were examined using multiple binary and multinomial logistic regressions.
RESULTS:
In men, a positive association was observed between daily occupational sedentary hours and WC, WHR, BMI and with high risk profiles that incorporated both BMI and WC (P<0.01). Controlling for vigorous-intensity LTPA in all models strengthened associations between sedentary behaviour and measures of obesity. In contrast, inverse associations were observed for occupational sedentary hours and WHR for women (P<0.05).
CONCLUSIONS:
In fully-employed men, occupational sedentary behaviour was positively associated with obesity risk that was not attenuated by physical activity. In women, an increase in obesity risk was not observed with sedentary behaviour. Gender differences in the health effects of sedentary behavior require further study.