Body mass index, physical activity, and serum markers of inflammation, immunity, and insulin resistance.

Abstract

Epidemiologic studies examining circulating levels of inflammatory markers in relation to obesity and physical inactivity may aid in our understanding of the role of inflammation in obesity-related cancers. However, previous studies on this topic have focused on a limited set of markers. We evaluated associations between body mass index (BMI) and vigorous physical activity level, based on self-report, and serum levels of 78 inflammation-related markers. Markers were measured using a bead-based multiplex method among 1,703 men and women, ages 55-74 years, and with no prior history of cancer at blood draw, and selected for case-control studies nested within the Prostate, Lung, Ovarian, and Colorectal Cancer Screening Trial. Analyses were adjusted for age, sex, smoking, case-control study, physical activity, and BMI. Twelve markers were positively associated with BMI after FDR correction. ORs and 95% confidence interval (CI) for highest versus lowest levels of CCL2/MCP-1, CXCL5/ENA-78, sTNFRII, CXCL10/IP-10, CXCL6/GCP2, CCL13/MCP-4, amylin, CRP, C-peptide, CCL19/MIP-3b, insulin, and leptin were: 1.50 (1.14-1.98), 1.52 (1.12-2.05), 1.61 (1.17-2.20), 1.69 (1.25-2.28), 1.74 (1.24-2.44), 1.75 (1.22-2.50), 1.91 (1.31-2.78), 2.41 (1.36-4.25), 2.78 (1.83-4.24), 3.30 (2.28-4.78), 4.05 (2.51-6.55), and 50.03 (19.87-125.99) per 5 kg/m(2), respectively. Only CXCL12/SDF-1a was associated with physical activity (≥3 vs. <1 h/wk; OR, 3.28; 95% CI, 1.55-6.94) after FDR correction. BMI was associated with a wide range of circulating markers involved in the inflammatory response. This cross-sectional analysis identified serum markers could be considered in future studies aimed at understanding the underlying mechanisms linking inflammation with obesity and obesity-related cancers.