Association between ghrelin and cardiovascular indexes in healthy obese and lean men

OBJECTIVE: Obesity is an increasingly common condition and is associated with excess morbidity and mortality, including clinical and subclinical cardiac dysfunction. The role of hormones involved in energy homeostasis, including ghrelin and leptin, in cardiovascular function remains incompletely understood. Therefore, we sought to evaluate the association between systemic ghrelin and leptin levels with indexes of cardiovascular structure and function. DESIGN AND MEASUREMENTS: We measured serum ghrelin and leptin levels in 25 clinically healthy obese men and 25 lean controls, using commercially available immunoassays. We also assessed right and left ventricular structure and function using cardiac magnetic resonance imaging. We then investigated the association between serum ghrelin and leptin levels with cardiac indexes, using univariate and multivariate analysis. RESULTS: There was an independent association between serum ghrelin levels and height-adjusted right ventricular mass (r = -0.324, P = 0.026), right ventricular end-diastolic volume (r = -0.363, P = 0.017) and right ventricular end-systolic volume (r = -0.398, P = 0.009) as well as right ventricular ejection fraction (r = 0.317, P = 0.050). There was no significant association between serum ghrelin and indexes of left ventricular structure or function. We also identified an association between serum leptin levels and resting heart rate (r = 0.391, P = 0.002). There was an association between serum leptin and height-adjusted left ventricular mass on univariate, but not on multivariate, analysis. CONCLUSIONS: Serum ghrelin is associated with right ventricular cardiovascular indexes and serum leptin is associated with resting heart rate. These associations indicate a close interaction between the endocrine and cardiovascular systems in obesity.