Purpose: Physical activity is associated with decreased adiposity-related inflammation in adults. Whether this association is independent of central obesity is unknown but important for understanding the mechanisms associated with reducing cardiometabolic disease risk through physical activity. This study examined whether associations of physical activity and obesity-related inflammatory markers were independent of central adiposity.
Methods: Between 2002 and 2005, 1970 participants from the Multi-Ethnic Study of Atherosclerosis completed detailed health history and physical activity questionnaires, underwent physical measurements including computed tomography to quantify abdominal visceral and subcutaneous fat, and measurements of adiponectin, leptin, interleukin-6, tumor necrosis factor-alpha, and resistin. Statistical analyses included analysis of covariance and multivariable-adjusted regression.
Results: The mean (range) age of participants was 64.7 (55-84) yr and 50% were women. After adjustment for age and sex, and compared with the lowest quartile, inflammatory markers in the highest quartile of moderate-to-vigorous physical activity were 16% higher for adiponectin and 30%, 26%, and 9% lower for leptin, interleukin-6, and resistin, respectively (P < 0.05 for all). In linear regression adjusted for demographics, dyslipidemia, hypertension, diabetes, smoking, glomerular filtration rate, renin, and aldosterone, each standard deviation increment of moderate-to-vigorous physical activity was associated with significantly higher levels of adiponectin (β = 0.04) and lower levels of leptin (β = -0.06), interleukin-6 (β = -0.08), and resistin (β = -0.05, P < 0.05 for all). The associations with leptin, interleukin-6, and resistin were independent of total and central adiposity (P < 0.05), whereas the association between moderate-to-vigorous physical activity and adiponectin was attenuated by central adiposity (P > 0.05). There were no significant interactions by race/ethnicity or sex.
Conclusions: Moderate-to-vigorous physical activity was associated with a more favorable profile of inflammatory markers, independent of relevant cardiometabolic disease risk factors including central obesity.