Overweight and obesity are considered as chronic low-grade inflammation accompanied by imbalanced production of adipokines. The aim of this study was to elucidate the relationship between serum bilirubin, which is an endogenous antioxidant with anti-inflammatory activity, and pro- and anti-inflammatory serum adipokines in asymptomatic normal weight and overweight individuals. Healthy men and women aged 25-49 participated in this cross-sectional study. All participants underwent fasting serological measurements of adipokines, interleukin-6, tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP), total and direct serum bilirubin, and other biochemical parameters. Participants were divided into normal weight and overweight groups. We found a significant negative association between total bilirubin and CRP, TNF-α, visfatin and resistin values, and a significant positive association between total bilirubin and adiponectin values in both normal-weight and overweight groups. Importantly, after adjusting for body mass index, we also found a significant negative association between total serum bilirubin levels and both visfatin and CRP serum levels. Moreover, visfatin, resistin and CRP were predictors of the total serum bilirubin levels.
Keywords: Adipokines; Bilirubin; C-reactive protein; Cross-sectional studies; Obesity; Overweight.