Maliqueo M, Atwater I, Lahsen R, Pérez-Bravo F, Angel B, Sir-Petermann T
Department of Medicine, San Juan de Dios Hospital, School of Medicine, University of Chile, Santiago, Chile.
Hum Reprod. 2003 Dec;18(12):2683-8. doi: 10.1093/humrep/deg482.
The aim of this study was to establish the effect of polycystic ovary syndrome (PCOS) adjusted for adiposity on proinsulin concentrations.
Ninety-one women with PCOS and 72 normal cycling (NC) women were recruited. A 2 h, 75 g oral glucose tolerance test was performed. Glucose and insulin were measured in each sample. Proinsulin and C-peptide were determined at 0 and 30 min and the fasting proinsulin/insulin ratio (PI/I) was calculated. Insulin sensitivity was estimated by insulin sensitivity index (ISI) composite, and beta-cell function was estimated by insulinogenic index.
Insulin, proinsulin and C-peptide concentrations were higher in women with PCOS than in NC women (P < 0.05). PI/I and insulinogenic index were similar in both groups. Proinsulin concentrations increased with body mass index (P < 0.05) only in women with PCOS; therefore, proinsulin concentrations were higher in obese PCOS patients compared with obese control women (P < 0.05). Moreover, a positive association between proinsulin concentrations and waist diameter adjusted for C-peptide (P < 0.05) and a negative association between proinsulin concentrations and ISI composite values were observed in PCOS patients (P < 0.05).
Data suggest that in PCOS patients an elevated proinsulin concentration could reflect insulin resistance more than beta-cell dysfunction. However, the elevated concentration of proinsulin in these patients could also result from impaired beta-cell function resulting from intra-abdominal obesity independently of insulin resistance.
本研究旨在确定校正肥胖因素后多囊卵巢综合征（PCOS）对胰岛素原浓度的影响。
招募了91名患有PCOS的女性和72名月经周期正常（NC）的女性。进行了2小时75克口服葡萄糖耐量试验。测量每个样本中的葡萄糖和胰岛素水平。在0分钟和30分钟时测定胰岛素原和C肽，并计算空腹胰岛素原/胰岛素比值（PI/I）。通过胰岛素敏感性指数（ISI）综合评估胰岛素敏感性，通过胰岛素生成指数评估β细胞功能。
PCOS女性的胰岛素、胰岛素原和C肽浓度高于NC女性（P<0.05）。两组的PI/I和胰岛素生成指数相似。仅在PCOS女性中，胰岛素原浓度随体重指数增加（P<0.05）；因此，肥胖的PCOS患者的胰岛素原浓度高于肥胖的对照女性（P<0.05）。此外，在PCOS患者中观察到，校正C肽后的胰岛素原浓度与腰围呈正相关（P<0.05），胰岛素原浓度与ISI综合值呈负相关（P<0.05）。
数据表明，在PCOS患者中，胰岛素原浓度升高可能更多地反映胰岛素抵抗而非β细胞功能障碍。然而，这些患者胰岛素原浓度升高也可能是由于腹型肥胖导致的β细胞功能受损，而与胰岛素抵抗无关。
