Plasma omentin-1 levels are reduced in non-obese women with normal glucose tolerance and polycystic ovary syndrome

Abstract

Objective: Omentin-1 is a novel adipokine that increases insulin sensitivity and is expressed in visceral adipose tissue. The aim of this study was to determine the metabolic parameters that influence plasma omentin-1 levels in women with polycystic ovary syndrome (PCOS). Design and methods: A cross-sectional study was performed in 87 women with PCOS and 53 body mass index (BMI)-matched healthy controls including 39 non-obese, normal-weight (NW) PCOS women with normal glucose tolerance (NGT) and 44 BMI-and homeostasis model assessment (HOMA)-matched controls. Indices of insulin sensitivity, metabolic variables, circulating androgen levels, serum adiponectin, and omentin-1 levels were measured. A 75 g oral glucose tolerance test was performed in all participants. Results: Plasma omentin-1 levels were significantly lower in women with PCOS compared with those in BMI-matched controls (P!0.001). A significantly lower level of plasma omentin-1 was observed in non-obese women with PCOS and NGT compared with that in BMI-and HOMA-matched controls (P!0.001). Omentin-1 level was negatively correlated with BMI, indices of insulin sensitivity, and circulating androgens and was associated with greater 2 h postprandial glucose, C-peptide, and insulin levels compared with fasting values. Within the NW and NGT groups, omentin-1 levels remained negatively correlated with BMI, 2 h postprandial C-peptide, and circulating androgens and demonstrated a negative linear trend according to quartile of free testosterone (PZ0.028). Conclusions: Plasma levels of omentin-1 were reduced in non-obese women with PCOS and NGT. Postprandial hyperinsulinemia and hyperglycemia contributed more to lower omentin-1 levels than did fasting values in the setting of PCOS. Increased androgen levels contributed to decreased omentin-1 levels in women with PCOS.

Evaluation of the relationship between circulating omentin-1 concentrations and components of the metabolic syndrome in adults without type 2 diabetes or cardiovascular disease

“…The correlation between HDL cholesterol and omentin-1 has been previously described in the settings of obesity, metabolic syndrome, diabetes, and cardiovascular disease [4,8,10,12,13,17,26]. However, unlike other studies, we found that the association was primarily in men and in the presence of the metabolic syndrome.…”

Features of omental adipose tissue in endometrial cancer patients with ‘standard’ or ‘metabolically healthy’ obesity: associations with tumor process characteristics

“…The same conclusion can be made in regard of omentin IHC studies advisability, since—as had been discovered by us—a connection between this adipokine mRNA expression in omental fat and clinical-morphological EC features was rather modest (Table 4). Of note, in EC patients’ population we could not find any association between serum omentin concentration or its mRNA expression in omental tissue samples and BMI value (data not presented) in spite of published evidence of negative correlation between serum omentin level and excessive body mass (Tan et al 2008) [although there is also a report stating the contrary (Choi et al 2011)]. One also should not forget that while omentin is commonly viewed as a typical visceral adipokine, it (as already mentioned in Introduction) is mostly produced by fat tissue stromal cells but not adipocytes (Yang et al 2006).…”

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

“…In the setting of PCOS, plasma omentin-1 concentrations were found to decrease in non-obese women with normal glucose tolerance and PCOS and overweight insulin-resistant women with PCOS when compared with control subjects (Table 1; Tan et al 2008a, Choi et al 2011. In addition, the expression of omentin-1 at both mRNA and protein levels in omental adipose tissue is decreased in non-obese women with PCOS compared with controls (Tan et al 2008a).…”