Association between physical activity energy expenditure and inflammatory markers in sedentary overweight and obese women

Objective: Chronic subclinical inflammation and regular physical activity have opposing relationships to obesity-related metabolic diseases. Yet, the association between chronic inflammation and physical activity has rarely been examined in obese subjects. We examined the association between physical activity energy expenditure (PAEE), total (TEE) and resting energy expenditure (REE) and cardiorespiratory fitness (VO(2)peak) with inflammatory markers in overweight/obese women. Design: Cross-sectional study. Methods: The study included 152 overweight/obese postmenopausal women who were sedentary and free of chronic/inflammatory diseases (mean age: 57.5 (95% confidence interval (CI) 56.7-58.3) years, body mass index (BMI): 32.5 (95% CI 31.8-33.2) kg m(-2)). The following parameters were measured: TEE (doubly labeled water), REE (indirect calorimetry), PAEE (as (TEE x 0.90)-REE), VO(2)peak (ergocycle) and serum high-sensitive C-reactive protein (hsCRP), haptoglobin, soluble tumor necrosis factor-alpha receptor 1 (sTNFR1), interleukin-6, orosomucoid and white blood cells. Results: Sedentary women with the highest tertile of PAEE (1276 (1233-1319) kcal day(-1)) had lower concentrations of hsCRP and haptoglobin than those in the lowest tertile (587 (553-621) kcal day(-1)) after adjustment for fat mass (P<0.05). Soluble TNFR1 was positively correlated with VO(2)peak, TEE and REE (P<0.05), and hsCRP and orosomucoid were positively associated with REE (P<0.01), whereas haptoglobin was negatively associated with PAEE (P<0.05). In stepwise regression analyses that examined the concomitant associations of components of energy expenditure with inflammatory markers, PAEE remained the only predictor of hsCRP and haptoglobin (P<0.05), explaining 14 and 5%, respectively, of their variation, whereas REE was the only predictor of orosomucoid (r(2) = 0.05, P = 0.02) after adjustment for fat mass. Adding leptin to the regression models results in similar relationships between inflammatory markers and components of energy expenditure. Conclusion: PAEE is an independent predictor of hsCRP and haptoglobin in sedentary overweight/obese postmenopausal women free of chronic disease. Our data support the role of physical activity in reducing subclinical inflammation and risk of metabolic and cardiovascular diseases. International Journal of Obesity (2010) 34, 1387-1395; doi: 10.1038/ijo.2010.55; published online 6 April 2010