Korean J Obstet Gynecol.
2000 Apr;43(4):675-681.
Plasma Leptin Levels in Polycystic Ovary Syndrome: In Relation to Insulin Resistance
Abstract
OBJECTIVES
To investigate the leptin levels and their relations with BMI, body fat, basal insulin and insulin resistance (sensitivity) in polycystic ovary syndrome(PCOS). And to determine whether acute hyperinsulinemia affects the leptin levels. Materials and methods: In 15 PCOS patients and body fat-matched 22 normal controls, plasma leptin levels and fasting basal insulin levels were measured. The correlations between leptin and BMI, body fat and basal insulin levels were analysed for PCOS and controls. In addition, the insulin sensitivity was measured by 2-hour euglycemic hyperinsulinemic clamp test and the relation with leptin levels was analysed for the PCOS.
RESULTS
Basal leptin levels were higher in PCOS group (12.74+/-0.65ng/ml) than control group (9.81+/-0.72ng/ml). In control group, basal leptin levels were positively correlated with BMI (r2=0.45, p<0.05), body fat (r2=0.23, p<0.05) and basal insulin (r2=0.17, p<0.05). But, in PCOS group, only BMI showed a significant correlation with leptin levels (r2=0.32, p<0.05), but body fat, insulin and insulin sensitivity index were not associated with the leptin levels. After 2 hours of insulin clamp in PCOS group, the leptin levels did not show a significant change.
CONCLUSION
It appears that the leptin levels in PCOS are higher than controls and are not associated with body fat, basal insulin and insulin resistance in contrast to controls. The leptin levels did not increase as expected according to the increase of body fat and insulin. These results suggest that the regulation mechanism of leptin may be a complicated process involving body fat, insulin and insulin resistance, and the insulin resistance of adipocyte may negatively influence to the stimulatory effect of insulin and adiposity on the leptin secretion in PCOS. Acute hyperinsulinemia does not affect the leptin levels.
