Alteration of ghrelin/obestatin ratio in adolescence with polycystic ovarian syndrome

Abstract

Ghrelin, an endoggenous for the growth hormone secretagogue receptor, has been shown to participate in the regulation of energy homeostasis and pituitary hormone secretion. Obestatin, encoded by the same gene as ghrelin, is described as a physiological opponent of ghrelin. Ghrelin and obestatin are altered in polycystic ovary syndrome (PCOS), which is characterized by insulin resistance and pituitary hormone secretion disorder. The aim of this study was to evaluate ghrelin/obestatin imbalance in relation to insulin resistance and pituitary hormone in adolescence with PCOS. This restrospective case–control study included 33 adolescence with PCOS and 38 control adolescence. Ghrelin and obestatin concentrations in serum were determined by RIA, and the serum fasting glucose and Insulin were determined by the glucose oxidase color method and INS-EASIA. The serum LH and FSH were measured by highly specific hemiluminescence immunoassays. We found that the serum ghrelin levels and ghrelin/obestatin ratio were significant lower in PCOS group than in control group, and the serum obestatin levels were significant higher in PCOS group than in control group. The ghrelin/obestatin ratios were negatively correlation with LH/FSH ratio and insulin resistant index in PCOS group. The findings of this study suggest that ghrelin/obestatin imbalance may play a role in pathogenesis of adolescent PCOS.

Chinese abstract

生长激素释放肽ghrelin是参与能量调节和垂体激素分泌的一种生长激素促分泌素受体。与ghrelin编码基因相同的肥胖抑制素Obestatin被称为ghrelin的生理拮抗剂。多囊卵巢综合征（PCOS）的患者特征是胰岛素抵抗和垂体激素分泌障碍。此类患者体内Ghrelin和obestatin发生变化, 本研究的目的是评估青春期PCOS患者的胰岛素抵抗和垂体激素水平与ghrelin/obestatin比值失衡之间的关系。本次回顾性病例对照研究包括33例青春期PCOS患者及38例对照组成员。采用放射免疫法测定血清中Ghrelin和obestatin浓度, 葡萄糖氧化酶显色法和INS-EASIA法测定血清空腹血糖和胰岛素水平。血清LH和FSH采用高特异性半发光免疫分析法测定。研究发现, PCOS组血清ghrelin水平及ghrelin/obestatin比值明显低于对照组, 而其体内血清obestatin水平则明显升高。PCOS组ghrelin/obestatin比值与LH/FSH比值以及胰岛素抵抗指数呈负相关。本研究结果表明ghrelin/obestatin比值失衡可能与青春期PCOS的发病机制相关。

Keywords:

• Polycystic ovary syndrome
• adolescence
• ghrelin/obestatin ratio
• insulin resistance
• pituitary hormone

Acknowledgements

The technical assistance of Jiali WU is kindly acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.