Positive correlation of serum leptin with estradiol levels in patients with polycystic ovary syndrome

Abstract

Patients with polycystic ovary syndrome (PCOS) usually are obese, insulin resistant and hyperinsulinemic. The known association between leptin, obesity and insulin action suggests that leptin may have a role in PCOS but this has only been addressed peripherally. This study was designed to assess the relationship between serum leptin and the anthropometric, metabolic and endocrine variables of obese (body mass index, BMI ≥30 kg/m 2 ) and non-obese (BMI <30 kg/m 2 ) PCOS patients. Twenty-eight PCOS patients and 24 control women subdivided into obese and non-obese groups were evaluated. Leptin, androgens, lipids, gonadotrophins and insulin-glucose response to the oral glucose tolerance test were measured by radioimmunoassay in all participants. The assays were done all in one time. The areas under the insulin curve (AUC-I) and the glycemia curve were calculated to identify patients with insulin resistance. Mean leptin levels were not significantly higher in patients with PCOS compared to the control group (21.2 ± 10.2 vs 27.3 ± 12.4 ng/ml). Leptin levels were found to be significantly higher in the obese subgroups both in patients with PCOS (26.9 ± 9.3 vs 14.1 ± 7.0 ng/ml) and in the control group (37.3 ± 15.5 vs 12.9 ± 5.8 ng/ml). The leptin of the PCOS group was correlated with BMI (r = 0.74; P < 0.0001) and estradiol (r = 0.48; P < 0.008) and tended to be correlated with the AUC-I (r = 0.36; P = 0.05). Of the parameters which showed a correlation with leptin in PCOS, only estradiol and probably insulinemia (AUC-I) did not show a significant correlation with BMI, suggesting that the other parameters were correlated with leptin due to their correlation with BMI. Estradiol correlated with leptin in PCOS patients regardless of their weight.

Role of the N, N′-dimethylbiguanide metformin in the treatment of female prepuberal BALB/c mice hyperandrogenized with dehydroepiandrosterone

“…This profile suggests an increased steroidogenic activity, which is widely described in PCOS (Franks et al 2000, Abbott et al 2002. Evidence shows that follicles from anovulatory women with PCOS hypersecrete E when compared with size-matched follicles from normal ovaries or polycystic ovaries from ovulatory women (Franks et al 2000, Mendonca et al 2004, Doi et al 2005. These findings also support those of the current study.…”

Visfatin and leptin levels in women with polycystic ovaries undergoing ovarian stimulation

“…On the other hand, insulin increases leptin production (23), contributing to the hyperleptinemia that accompanies the insulin resistance state, as in PCOS (24). However, the present data contradict other studies (21,25,26), where, in women with PCOS, serum leptin was negatively correlated with E 2 levels, and no significant correlations were observed between serum leptin and LH, total T, and FAI, as previously reported (25). Given the pulsatile way of leptin secretion, an alteration of its normal pattern might be expected in PCOS women (27).…”

Study of Association of Leptin and Insulin Resistance Markers in Patients of PCOS

“…Polycystic ovary syndrome (PCOS) is an endocrine disorder characterized by menstrual disturbances, clinical and biochemical manifestations of hyperandrogenism and polycystic ovaries [9]. The discovery of leptin, and its association with energy balance and the reproductive endocrine axis, has led to considerable interest in the association between polycystic ovary and leptin levels.…”

“…HOMA-IR was calculated as the product of the fasting plasma insulin value (mU/ml) and the fasting plasma glucose value (mg/dl), divided by 405 (9). HOMA b = 360 9 [insulin]/([glucose] -63) % (glucose in mg/dl) [9].…”

“…HOMA b = 360 9 [insulin]/([glucose] -63) % (glucose in mg/dl) [9]. Insulin levels were estimated by Chemiluminescence immunoassay (CLIA) in Access 2 Beckmann Coulter.…”