Plasma levels of leptin and ghrelin and their correlation with BMI, and circulating lipids and glucose in obese Tunisian women

Background: A National Survey on the Effect of Nutrition conducted in 1996-1997 showed a 14% overall prevalence of obesity in Tunisia with a female predominance. Leptin and ghrelin play crucial roles in regulating body weight and energy balance. Leptin, an anorectic hormone, and ghrelin, an orexigenic hormone, appear to interact with glucose and lipid metabolism. Objectives: To determine the circulating levels of ghrelin and leptin in obese Tunisian women and to investigate the correlations of these hormones with body mass index (BMI), and circulating lipids and glucose. Methods: Forty obese women were recruited from patients in the "C" Unit of the National Institute of Nutrition and Food Technology. Twenty normal women were recruited as controls. Plasma levels of the studied variables were measured in patients from both groups and findings were analyzed. Results: Circulating levels of leptin were significantly higher, while high-density lipoprotein (HDL)-cholesterol and ghrelin levels were significantly lower in the obese women. In the obese women, significant positive correlations were found between circulating levels of leptin and low-density lipoprotein (LDL)-cholesterol, BMI, and glucose; and ghrelin and HDL-cholesterol. Significant negative correlations were found between circulating levels of leptin and HDL-cholesterol and ghrelin; and ghrelin and leptin, LDL-cholesterol, BMI, and glucose. Multivariate analysis revealed that ghrelin was significantly associated with HDL-cholesterol, LDL-cholesterol, and blood glucose. Conclusions: The significant negative correlation between leptin and ghrelin suggests that these two hormones may be antagonistic. Increased levels of ghrelin are correlated with decreased circulating levels of HDL-cholesterol and increased levels of LDL-cholesterol.