Relationship among leptin, ghrelin, obestatin and resistin with insulin resistance and beta cell function in type 2 diabetic patients

Diabetes mellitus (DM) is a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. İnsülin resistance is defined as disorder of biological response to insülin administrated exogenously or insülin secreted endogenously. The aim of our study was to compare the leptin, ghrelin resistin, obestatin levels in diabetic patients. Also we investigated insulin resistance and beta cell function and their relationship to hormonal leves in diabetic patients and control subjects.Total of 32 newly diagnosed and untreated patients with type 2 diabetes and 33 healthy controls were included in the study. From overnight fasting blood ghrelin, glucose, insülin, leptin, ghrelin, obestatin and resistin levels were measured.There was no significant differences between patient and control groups? leptin, obestatin and total ghrelin levels (p>0.05). Acyl-ghrelin levels were determined to be lower (p<0.04) while resistin levels were higher in diabetic patients compared to controls (p<0.025). In both groups, there was a positive correlation between HOMA-IR and leptin as well as HOMA-IR and resistin while a negative correlation existed between HOMA-IR and ghrelin. A negative correlation was found between obestatin and HOMA-IR in the type 2 DM patients. There was a positive correlation between obestatin and ghrelin levels, while a negative correlation between obestatin and leptin levels was observed in type 2 diabettes mellitus. A positive correlation was also determined between resistin and leptin levels in type 2 diabettes mellitus.In conclusion, lower acyl ghrelin levels may be involved in the regulation of energy balance by sending of fasting-satiety signals to brain. Acyl ghrelin, rather than total ghrelin, might be important in the type 2 DM. Increased resistin levels in diabetes, probably due to chronic inflammation, indicates that inflammation increases insulin resistance. No differences obestatin levels in both groups might be explained by the fact that subjects had similar BMI, but with younger age of diabetic subjects.