Serum acylated ghrelin, adiponectin and leptin levels in normal-weight and obese premenopausal women.

Ghrelin, leptin, and adiponectin play an important role in the regulation of energetic homeostasis, but physiological relationships between these hormones have not been elucidated. This study was therefore designed to characterize the association between serum acylated ghrelin, leptin, and adiponectin levels, as well as insulin resistance evaluated by homeostasis model of assessment in 32 normal-weight and 60 age-matched metabolically healthy obese women. In normal-weight, but not in obese women, we found a positive linear correlation between leptin and ghrelin (r=0.375; p=0.034). In the multiply regression analysis we observed the change of direction of leptin influence on acylated ghrelin level from positive in normal-weight (p=0.001) to negative in obese women without insulin-resistance (p=0.033); in obese women with insulin resistance leptin was not significantly associated with ghrelin. In neither group was any linear correlation found between ghrelin and adiponectin. However, by multivariate analysis adiponectin was positively associated with ghrelin, but only in obese women without insulin resistance (p=0.01). In conclusion, in normal-weight women leptin is positively correlated with acylated ghrelin. In obese women without insulin resistance different interactions between both hormones might reflect a physiological mechanism of adaptation to a positive energy balance.