Adiposity explains associations between sedentary behavior and CV risk factors
MedWire News: Markers of adiposity largely explain the association between sedentary behavior and cardiometabolic risk factors, study findings suggest.
Emmanuel Stamatakis and Mark Hamer, from University College London in the UK, found that body mass index (BMI) and waist circumference (WC) explained between 32% and 95% of the associations between sedentary behavior and several nonadiposity-related cardiovascular (CV) risk markers, including total cholesterol, high-density lipoprotein (HDL) cholesterol, and systolic (SBP) and diastolic blood pressure (DBP).
In a previous study, the researchers found that sedentary behavior was significantly and independently associated with nonadiposity-related CV risk markers.
To investigate the extent to which these associations could be explained by BMI and WC, Stamatakis and Hamer used data from over 5000 participants of the 2008 Health Survey for England, who had adiposity and nonadiposity measures available. All participants provided information on their sedentary behavior, characterized by activities that involve sitting, such as TV watching or sitting at work.
Writing in the journal Obesity the team reports that addition of BMI and WC into an established logistic regression model that assessed the independent association between sedentary behavior and each nonadiposity risk marker, "considerably weakened" the associations they had previously observed.
Furthermore, BMI and WC were found to explain a large proportion of these associations, they say.
Specifically, BMI explained 95%, 65%, 92%, and 32% of the association between total sedentary time and SBP, DBP, HDL cholesterol, and total cholesterol, respectively. The respective degrees of association explained by WC were 90%, 61%, 84%, and 38%.
The researchers note that because their study was cross-sectional, they were unable to determine whether higher BMI or WC mediated increased sedentary behavior or vice-versa.
"Future longitudinal studies should further examine the mediatory role of adiposity in explaining the associations between sedentary behavior and cardiometabolic risk," they conclude.
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By Nikki Withers