Hutchison Samantha K, Harrison Cheryce, Stepto Nigel, Meyer Caroline, Teede Helena J
Jean Hailes Foundation Research Group, Monash University Institute of Health Services Research, Melbourne, Australia.
Diabetes Care. 2008 Jul;31(7):1427-32. doi: 10.2337/dc07-2265. Epub 2008 Apr 4.
Polycystic ovary syndrome (PCOS) is an insulin-resistant state with insulin resistance being an established therapeutic target; however, measurement of insulin resistance remains challenging. We aimed to 1) determine serum retinol-binding protein 4 (RBP4) levels (purported to reflect insulin resistance) in women with PCOS and control subjects, 2) examine the relationship of RBP4 to conventional markers of insulin resistance, and 3) examine RBP4 changes with interventions modulating insulin resistance in overweight women with PCOS.
At baseline, 38 overweight women (BMI >27 kg/m(2)) with PCOS and 17 weight-matched control subjects were compared. Women with PCOS were then randomly assigned to 6 months of a higher-dose oral contraceptive pill (OCP) (35 microg ethinyl estradiol/2 mg cyproterone acetate) or metformin (1 g b.i.d.). Outcome measures were insulin resistance (total insulin area under the curve) on an oral glucose tolerance test, RBP4, and metabolic/inflammatory markers.
Overweight women with PCOS were more insulin resistant than control subjects, yet RBP4 levels were not different in women with PCOS versus those in control subjects (35.4 +/- 4.3 vs. 28.9 +/- 3.1 microg/ml, P = 0.36). RBP4 correlated with cholesterol and triglycerides but not with insulin resistance. Metformin improved insulin resistance by 35%, whereas the OCP worsened insulin resistance by 33%. However, RBP4 increased nonsignificantly in both groups (43.7 +/- 6.3 vs. 42.6 +/- 5.5 microg/ml, P = 0.92).
Overweight women with PCOS were more insulin resistant than control subjects, but this finding was not reflected by RBP4 levels. RBP4 correlated with lipid levels but not with insulin resistance markers. RBP4 levels did not change when insulin resistance was reduced by metformin or increased by the OCP. These data suggest that RBP4 is not a useful marker of insulin resistance in PCOS but may reflect other metabolic features of this condition.
多囊卵巢综合征（PCOS）是一种胰岛素抵抗状态，胰岛素抵抗是既定的治疗靶点；然而，胰岛素抵抗的测量仍然具有挑战性。我们旨在：1）测定PCOS女性和对照受试者的血清视黄醇结合蛋白4（RBP4）水平（据称可反映胰岛素抵抗）；2）研究RBP4与胰岛素抵抗传统标志物的关系；3）研究超重PCOS女性中RBP4随调节胰岛素抵抗的干预措施的变化。
在基线时，对38名超重PCOS女性（BMI>27kg/m²）和17名体重匹配的对照受试者进行比较。然后将PCOS女性随机分配接受6个月的高剂量口服避孕药（OCP）（35μg炔雌醇/2mg醋酸环丙孕酮）或二甲双胍（1g，每日两次）治疗。观察指标为口服葡萄糖耐量试验中的胰岛素抵抗（曲线下胰岛素总量）、RBP4以及代谢/炎症标志物。
超重PCOS女性比对照受试者更具胰岛素抵抗，但PCOS女性的RBP4水平与对照受试者无差异（35.4±4.3 vs. 28.9±3.1μg/ml，P = 0.36）。RBP4与胆固醇和甘油三酯相关，但与胰岛素抵抗无关。二甲双胍使胰岛素抵抗改善35%，而OCP使胰岛素抵抗恶化33%。然而，两组中RBP4均无显著升高（43.7±6.3 vs. 42.6±5.5μg/ml，P = 0.92）。
超重PCOS女性比对照受试者更具胰岛素抵抗，但这一发现未通过RBP4水平体现。RBP4与血脂水平相关，但与胰岛素抵抗标志物无关。当胰岛素抵抗通过二甲双胍降低或通过OCP升高时，RBP4水平未发生变化。这些数据表明，RBP4在PCOS中并非胰岛素抵抗的有用标志物，但可能反映该疾病的其他代谢特征。
