Leptin concentrations in patients with polycystic ovary syndrome before and after met-formin treatment depending on insulin resistance, body mass index and androgen con-centrations--introductory report.

Abstract

Polycystic ovary syndrome (PCOS) is an endocrinological and metabolic disorder which may concern about 3-8 % of women. Some PCOS women have the increased leptin concentration in blood serum. Leptin concentration is higher in patients with high body mass index (BMI) and impaired tissue sensitivity to insulin. The aim of this study was to determine leptin concentrations in PCOS patients before and after metformin treatment depending on BMI, insulin resistance calculated on the basis of the Homeostasis Model Assessment (HOMA) index, as well as concentrations of androgens: testosterone and androstendion. Such values as BMI, insulin resistance according to the HOMA index, and concentrations of androstendion, testosterone and leptin were determined in 35 patients with PCOS before and after 3-month metformin treatment administered in daily doses of 2 x 850 mg. Increased leptin levels before the therapy were observed in 91.3 % (21 out of 23) of obese patients, in 75% (9 out of 12) non-obese patients, in 100% (8 patients) insulin resistance women, in 81.5% (22 out of 27) insulin sensitive patients, in 94.7 % (18 out of 19) women with elevated androstendion concentration and in 75% (12 out of 16) with normal androstendion concentration, in 93.7% (15 out of 16) patients with increased testosterone concentration and in 78.9% (15 out of 19) patients with testosterone concentrations within the normal range. After treatment statistically significant decrease in leptin concentration was obtained in the patients with BMI≤25, insulin-sensitive patients (HOMA<3.8) and patients whose testosterone and androstendion concentrations stayed within normal limits. Increased leptin concentrations may be one of the elements of PCOS clinical picture. Metformin treatment considerably reduces leptin concentration, if it is employed in non-obese PCOS patients, patients with normal an-drogen concentrations and those who not have an impaired glucose tolerance.

Impact of Treatment with Metformin on Adipocytokines in Patients with Polycystic Ovary Syndrome: A Meta-Analysis

“…However, the effect of metformin on adipocytokine levels remains controversial. Some studies reported positive results [ 27 – 30 , 34 – 40 ], whereas others found no significant changes in adipocytokine levels after metformin administration [ 26 , 31 ].…”

Targeting AMP-activated protein kinase in adipocytes to modulate obesity-related adipokine production associated with insulin resistance and breast cancer cell proliferation

“…Recent studies demonstrated that metformin treatment increased adiponectin plasma levels in women with polycystic ovary syndrome (PCOS) [23] and T2DM patients [24] while metformin treatment tends to decrease IL-6 plasma levels [23] as well as circulating levels of leptin [25] in PCOS patients, and significantly reduces resistin and TNF-α plasma levels [24] in T2DM patients. Moreover, metformin inhibition of TNF-α-induced IL-6 secretion was abolished after silencing of AMPKα1 in human umbilical vein endothelial cells [26].…”

Adipokines in reproductive function: a link between obesity and polycystic ovary syndrome

“…Treatment with troglitazone did not seem to alter leptin levels (Mantzoros et al 1997). By contrast, administration of metformin, an insulin sensitizer widely used for the treatment of T2DM, considerably reduced serum leptin concentrations in obese (MorinPapunen et al 1998) and non-obese PCOS patients (Marciniak et al 2009). The correlation between leptin and IR is thus still a matter of debate.…”