The effect of weight loss and treatment with metformin on serum vaspin levels in women with polycystic ovary syndrome

Abstract

Polycystic ovary syndrome (PCOS) is one of the commonest endocrine disorders in women of reproductive age, affecting 5-10% of them, and the leading cause of anovulatory infertility in developed countries [1,2]. The most frequent signs of PCOS are irregular menstruation, due to oligo-or anovulation, as well as signs of androgen excess, including hirsutism, oily skin, acne and androgenic alopecia [3].Patients with PCOS frequently have insulin resistance, pancreatic β-cell dysfunction, glucose intolerance, type 2 diabetes mellitus (T2DM) and dyslipidemia [1,[3][4][5]. Obesity, particularly visceral obesity, is another important feature of the syndrome and 38-88% Abstract. Many patients with polycystic ovary syndrome (PCOS) have insulin resistance, obesity (mostly visceral) and glucose intolerance, conditions associated with abnormalities in the production of vaspin, a novel adipokine that appears to preserve insulin sensitivity and glucose tolerance. The aim of the study was to assess serum vaspin levels in PCOS and the effects on vaspin levels of metformin or of weight loss. We studied 79 patients with PCOS and 50 healthy female volunteers. Normal weight patients with PCOS (n=25) were treated with metformin 850 mg bid for 6 months. Overweight/obese patients with PCOS (n=54) were prescribed a normal-protein, energy-restricted diet for 6 months; half of them were also given orlistat 120 mg tid and the rest were given sibutramine 10 mg qd. At baseline and after 6 months, serum vaspin levels and anthropometric, metabolic and hormonal features of PCOS were determined. Overall, patients with PCOS had higher vaspin levels than controls (p=0.021). Normal weight patients with PCOS had higher vaspin levels than normal weight controls (p=0.043). Vaspin levels were non-significantly higher in overweight/obese patients with PCOS than in overweight/obese controls. In normal weight patients with PCOS, metformin reduced vaspin levels non-significantly. In overweight/obese patients with PCOS, diet plus orlistat or sibutramine did not affect vaspin levels. Vaspin levels were independently correlated with body mass index in women with PCOS (p=0.001) and with waist circumference in controls (p=0.015). In conclusion, serum vaspin levels are elevated in PCOS but neither a small weight loss nor metformin affect vaspin levels significantly.

Relationship among plasma adipokines, insulin and androgens level as well as biochemical glycemic and lipidemic markers with incidence of PCOS in women with normal BMI

“…There is a controversy between our results, where no significant changes of vaspin plasma levels in nonobese PCOS women was observed and other studies which showed increased vaspin plasma levels in PCOS women [12,18,19] [18] study might represent a compensatory mechanism to preserve insulin sensitivity and glucose tolerance which are impaired in obesity.…”

New markers of insulin resistance in polycystic ovary syndrome

“…Positive associations with HOMA-IR and glucose were found, suggesting that high vaspin levels may be a consequence of insulin resistance. Similar results were found by Koiou et al [38]. In their study, serum vaspin levels were higher in both lean and obese PCOS patients than in controls.…”

Elevated vaspin and leptin levels are associated with obesity in prepubertal Korean children

“…Several pediatric studies, but not all, illustrated possible relationships between vaspin, insulin sensitivity, and obesity [13,20,21]. Some reported that weight reduction decreased circulating vaspin levels [22][23][24], but others did not [13,25].…”