The relationship between circulating levels of IL-۱۸ and leptin, HsCRP, blood pressure and cardiorespiratory function in obese and lean men

Introduction: Interleukin-۱۸ (IL-۱۸) is a proinflammatory cytokine that is produced in adipose tissue and skeletal muscle. The circulating levels of IL-۱۸ 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-۱۸ and leptin, high-sensitivity C-reactive protein (HsCRP), blood pressure and cardiovascular function in obese and lean men. Methods: In a descriptive-analytical study, ۱۹ obese men (Body Mass Index (BMI)≥۳۰ kg/m۲) and ۱۹ lean men (BMI≤۱۸) were selected as subjects. After ۱۲ 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<۰.۰۱ was used to analyze the collected data. Results: Serum IL-۱۸ levels in obese men were directly correlated with BMI and body fat percentage (BFP), but no significant correlation was observed in lean men. IL-۱۸ in obese and lean men was directly correlated with leptin and HsCRP. But, it was inversely correlated with cardiorespiratory function (VO۲max). IL-۱۸ levels in obese men were directly correlated with systolic blood pressure (SBP), but no significant correlation was found between IL-۱۸ levels and diastolic blood pressure (DBP). No significant correlation was observed between IL-۱۸ levels and SBP and DBP in lean men. Conclusion: It seems that changes in anthropometric characteristics, blood pressure, cardiorespiratory function and hormones such as leptin and HsCRP can be effective in IL-۱۸ changes. These findings reveal the role of IL-۱۸ in some inflammatory, metabolic (including diabetes and metabolic syndrome) and cardiovascular (hypertension pressure and atherosclerosis) disorders, especially in obese patients.