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

ABSTRACT Introduction: 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. Methods: In a descriptive-analytical study, 19 obese men (Body Mass Index (BMI)&ge;30 kg/m2) and 19 lean men (BMI&le;18) were selected as subjects. After 12 hours of fasting, blood samples were collected and general characteristics of the subjects were measured. The Pearson&rsquo;s correlation coefficient at a significance level of P<0.01 was used to analyze the collected data. Correspondence: Fatah Moradi, PhD. Physical Education and Sport Sciences, Saghez Branch, Islamic Azad University. Saghez, Iran Tel:+98 9144823733 Email: [email protected] Results: 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. Conclusion: 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.