Endocrine Abstracts

Introduction: Besides of the neuroendocrine actions including the stimulatory effects on growth hormone, prolactin and adrenocorticotropin release, acylated ghrelin (AG) plays a role in the regulation of metabolic processes, resulting in the decrease of insulin secretion and increase of hepatic glucose release. Despite of many earlier studies, the mechanisms involved in AG secretion have not been established. The aim of study was to assess the influence of leptin on AG.

Material and methods: The study was performed on 32 normal-weight (BMI 18.9–24.2 kg/m²) healthy women aged 22–47 yr, and 80 obese women (BMI 30.1–51.4 kg/m²) aged 22–46 yr without a diagnosis of metabolic syndrome according to ATP III criteria. Basal serum AG, leptin, insulin and glucose were measured. Insulin sensivity was assessed by homeostatic model of assessment (HOMA).

Results: In normal-weight women a positive correlation between leptin and AG was found (R=0.375; P=0.034), and in multiply regression analysis leptin positively influenced AG serum level (P=0.001). In obese women with HOMA <2.5 we could not demonstrate linear correlation between leptin and AG, however in multiply regression model leptin negatively influenced AG (P=0.035). We did not find such relationships in obese women with HOMA >2.5.

Conclusions: Leptin significantly influence AG in normal-weight healthy premenopausal women. In obese women without insulin resistance, different influence of leptin on AG seems to reflect a physiological mechanism of adaptation to the positive energy balance, protecting against hyperglycaemia. This mechanism is abolished in women with insulin resistance.