The relationship between circulating levels of IL-18 and leptin, HsCRP, blood pressure and cardiorespiratory function in obese and lean men

Interleukin-18 (IL-18) is a proinflammatory cytokine that is produced in adipose tissue and skeletal muscle. The circulating levels of IL-18 increases in obesity and some metabolic and cardiorespiratory diseases. The aim of the present study is to investigate the relationship between circulating levels of IL-18 and leptin, high-sensitivity C-reactive protein (HsCRP), blood pressure and cardiovascular function in obese and lean men.
In a descriptive-analytical study, 19 obese men (Body Mass Index (BMI)≥30 kg/m2) and 19 lean men (BMI≤18) were selected as subjects. After 12 hours of fasting, blood samples were collected and general characteristics of the subjects were measured. The Pearson’s correlation coefficient at a significance level of P Serum IL-18 levels in obese men were directly correlated with BMI and body fat percentage (BFP), but no significant correlation was observed in lean men. IL-18 in obese and lean men was directly correlated with leptin and HsCRP. But, it was inversely correlated with cardiorespiratory function (VO2max). IL-18 levels in obese men were directly correlated with systolic blood pressure (SBP), but no significant correlation was found between IL-18 levels and diastolic blood pressure (DBP). No significant correlation was observed between IL-18 levels and SBP and DBP in lean men.
It seems that changes in anthropometric characteristics, blood pressure, cardiorespiratory function and hormones such as leptin and HsCRP can be effective in IL-18 changes. These findings reveal the role of IL-18 in some inflammatory, metabolic (including diabetes and metabolic syndrome) and cardiovascular (hypertension pressure and atherosclerosis) disorders, especially in obese patients.