title: Plasma interleukin-8 concentrations are increased in obese subjects and related to fat mass and tumor necrosis factor-alpha system.
abstract: Obesity is associated with the increased risk of cardiovascular disease; however, mechanisms responsible for such an increase are not fully understood. IL-8 is a cytokine that might have atherogenic properties. Recent in vitro studies revealed that IL-8 is produced and secreted by human adipocytes. The aim of the present study was to evaluate plasma IL-8 concentrations in obese subjects and the relationships between circulating IL-8 and anthropometric and biochemical parameters and TNF-alpha system. A total of 75 subjects with normal glucose tolerance, 35 lean and 40 obese, were recruited for this study. Plasma IL-8 levels were measured in fasting state, after an oral glucose tolerance test and after the euglycemic hyperinsulinemic clamp. A significant increase in plasma IL-8 was observed in the obese group. In simple regression analysis, performed for the initial evaluation of relationships, plasma IL-8 was related to body mass index, percentage of body fat, fat mass (FM), and soluble TNF-alpha receptor 2 (sTNFR2) in both groups and with waist-to-hip ratio and sTNFR1 in the obese. In multiple regression analysis, FM, waist-to-hip ratio, gender, sTNFR2, and low density lipoprotein cholesterol were responsible for 44% of IL-8 variability. During oral glucose tolerance testing, mean plasma IL-8 concentrations increased in both groups, whereas clamp resulted in a significant increase in plasma IL-8 only in the obese. We conclude that plasma IL-8 levels are increased in obese subjects, and are related to FM and TNF-alpha system. Increase in circulating IL-8 might be one of the factors linking obesity with greater cardiovascular risk.
mesh_terms: D000273:Adipose Tissue; D000328:Adult; D015703:Antigens, CD / Q000097:blood; D001823:Body Composition; D001824:Body Constitution; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000209:etiology; D008078:Cholesterol, LDL / Q000097:blood; D005260:Female; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D016209:Interleukin-8 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000503:physiopathology; D018124:Receptors, Tumor Necrosis Factor / Q000097:blood; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; D012044:Regression Analysis; D012307:Risk Factors; D012727:Sex Characteristics; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*
chemical_list: D015703:Antigens, CD; D008078:Cholesterol, LDL; D007328:Insulin; D016209:Interleukin-8; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; D014409:Tumor Necrosis Factor-alpha