Circulating markers of inflammation and their link to indices of adiposity.

BACKGROUND Adipose tissue produces a number of inflammatory mediators. Circulating concentrations of these inflammatory markers are increasingly used as markers of local or systemic inflammation. This study compares results for 3 inflammatory adipokines measured using 2 techniques, (multiplex and ELISA), and determines the relationships with C-reactive protein (CRP), obesity, and the impact of moderate weight loss. SUBJECTS AND METHODS Fasting blood samples were collected at baseline and after a 24-week weight loss intervention. Interleukin 6 (IL-6), tumour necrosis factor alpha(TNF-alpha), and monocyte chemoattractant protein 1 (MCP-1) were measured using a standard ELISA technique or a new multiplex technique. A total of 54 women with complete data were included in this analysis. RESULTS Multiplex showed poor correlation with ELISA results, and were not significantly correlated with CRP. Using ELISA data, IL-6 and CRP were significantly correlated with body mass index (BMI) (r = 0.42 and r = 0.55), but MCP-1 and TNF-alpha were not (r = - 0.07 and r = 0.06). Changes in MCP-1, TNF-alpha, and IL-6 were not significantly different between control and weight loss groups. CRP was significantly reduced in weight loss vs. control group (p < 0.05), and change in CRP correlated with change in BMI (r = 0.31). CONCLUSION Circulating IL-6 and CRP, but not MCP-1 and TNF-alpha, are significantly associated with indices of adiposity in obese women. This study suggests that circulating IL-6 and CRP, but not MCP-1 and TNF-alpha, are useful markers of obesity-related inflammation.