糖耐量正常的多囊卵巢综合征者胰岛素分泌功能及血糖波动变化的研究

目的 探讨糖调节正常的多囊卵巢综合征(PCOS)患者动态血糖谱及胰岛素敏感性及胰岛素分泌的特点.方法 选择20名糖调节正常的PCOS患者作为研究组,20名正常女性为对照组,进行动态血糖监测系统(CGMS)、75 g口服匍萄糖耐最试验(OGTT)及胰岛素释放试验,分析比较CGMS中连续48 h的平均血糖水平(MBG)及其标准差(SDBG)和平均血糖波动幅度(MAGE),以及三餐后的血糖峰值及达峰时间;以Stumvoll公式估计第一相、第二相胰岛素分泌、稳态评估模型法评估基础胰岛素分泌功能,以稳态评估模型胰岛素抵抗指数和Cederhom公式评什胰岛素敏感性.结果 (1)PCOS组OGTT 1 h PG、OGTT 3 h PG均高于对照组(分别为P<0.01和P<0.05);PCOS组空腹胰岛素(FINS)、OGTT 30 min、1、2、3 h胰岛素(INS)均显著高于对照组(均P<0.01),PCOS组胰岛素释放峰值后移1 h;(2)PCOS患者日内MBG为(5.43±0.44)mmol/L,SDBG及MAGE分别为(0.66±0.24)mmol/L和(1.46±0.47)mmol/L,与对照组的差异均无统计学意义(均P>0.05).PCOS患者早餐后血糖的达峰时间显著迟于对照组分别为(40±18)min和(30±10)min,(P<0.05).(3)PCOS患者的胰岛素敏感性指数显著低于对照组(P<0.01).PCOS患者第一相和第二相胰岛分泌指数均显著高于对照组(均P<0.01).结论 正常糖耐量的PCOS者已出现(1)糖负荷后的胰岛素分泌高峰后移,(2)血糖波动异常,即早餐后血糖达峰时间延迟.(3)存在显著的外周胰岛素敏感性下降伴胰岛素分泌代偿性增加.

Insulin release and daily glucose change in polycystic ovary syndrome women with normal glucose tolerance

Objective To evaluate the characteristics of daily glucose change, insulin sensitivity, and insulin release in polycystic ovary syndrome (PCOS) women with normal glucose tolerance. Methods Oral glucose tolerance test (OGTY) with 75 g glucose was conducted on 20 PCOS women with normal glucose tolerance and 20 age-matched healthy women with normal menstruation. Before the glucose uptake and 30, 60, and 120 min after samples of venous blood were collected to detect the blood glucose and insulin. Continuous glucose monitoring system (CGMS) was used to monitor the glucose concentration of subcutaneous interstitial fluid so as to reflect the blood glucose level. Mean blood glucose level (MBG) and its standard deviation (SDBG), mean amplitude of glycemic excursion (MAGE), peak level of postprandial plasma glucose as well as its peaking time during a 48-hour period CGMS were calculated. Stumvoll first-phase and second-phase (1st PH and 2nd PH) insulin release during OGTT were evaluated by Stumvoll formula, whereas baseline insulin release by HOMA-B. Insulin sensitivity index (ISI) was evaluated by Cederhom formula. Results (1) The 1-hour and 3-hour plasma glucose levels during OGTT of the PCOS group were higher than those of the control group (P<0.01 and P <0.05 respectively). The fasting insulin level and insulin levels 30, 60,120, and 180 min after the glucose uptake during OGTT of the PCOS group were all significantly higher than those of the control group (all P<0.01). (2) The daily MBG, SDBG, and MAGE of the PCOS group were (5.43±0.44), (0.66±0.24), and (1.46±0.47) mmol/L respectively, all similar to those of the control group [(5.3±0.5 ), (0.67±0.27), and (1.7±0.7) mmol/L respectively, all P>0.05]. The peaking time of post-breakfast plasma glucose level of the PCOS group was (40±18) min, significantly longer than that of the control group [(30±10) min, P<0. 05]. (3) The ISI of the PCOS group was 64 (59-81), significantly lower than that of the control group [95(78 -102), P<0.01]. The Stumvoll 1st PH and 2nd PH insulin release levels of the PCOS group were 1779 (1411-2194) mU/L and 440 (361-545) mU/L respectively, both significantly higher than those of the control group [1217 (1056-1477) and 320 (283-375) mU/L respectively, P<0.01 and P<0.05]. Conclusion With normal glucose tolerance, the PCOS women show (1) a backwardly-shifted peak of glucose -stimulated insulin secretion, (2) an abnormal mode of daily glucose change characterized by a delayed peak of post-breakfast plasma glucose level, and (3) significant decrease of peripheral insulin sensitivity with compensated increase of insulin secretion.