新诊断2型糖尿病患者葡萄糖耐量试验与糖化血红蛋白水平的相关分析

目的 对比分析新诊断2型糖尿病及糖尿病前期患者口服葡萄糖耐量试验(OGTT)与糖化血红蛋白(HbAIc)水平变化的特点及影响因素. 方法 按照OGTT结果将受检者分为糖耐量正常组(正常组):31例,年龄29～75岁,平均(48.4±15.3)岁;空腹血糖受损组(血糖受损组):33例.年龄38～72岁,平均(50.8±9.8)岁;糖耐量受损组:34例,年龄33～74岁,平均(54.5±11.4)岁;2型糖尿病组(T2DM组):117例,年龄29～75岁,平均(54.3±14.1)岁.采用OGTT试验、HbAlc结果评价糖代谢状态,胰岛β细胞功能指数(HOMA-E)、OGTT 30 min胰岛素分泌增值与血糖增值比值(△I30/△G330)、胰岛素分泌曲线下面积(AUCINS)及胰岛素抵抗指数(HOMA-IR)分别反映胰岛β细胞分泌功能和胰岛素抵抗情况. 结果 (1)T2DM、糖耐量受损组和正常组HbAlc分别为7.41%、5.85%和5.21%,差异有统计学意义(P<0.01),T2DM、糖耐量受损组和血糖受损组HOMA-β指数与正常组比较,分别下降了53.1%(P<0.01)、29.3%(P<0.01)和23.4%(P<0.05),T2DM组HOMA-IR分别是正常组的1.66倍(P<0.01)、血糖受损组的1.29倍(P<0.001)和糖耐量受损组的1.44倍(P<0.05);(2)HbAIc与糖负荷后3 h血糖水平相关性最高(r=0.71,P<0.01),且独立相关;△I30/△G330与糖负荷后1 h和2 h血糖水平独立负相关(P<0.01);AUCINS只与糖负荷后3 h血糖水平独立负相关(P<0.01);HOMA-β与2 h以外的其他各点血糖独立负相关(P<0.01);HOMA-IR与OGTT各点血糖水平均呈正相关(P<0.01或P<0.05);三酰甘油与空腹血糖独立正相关(P<0.05),腰围与1/2 h血糖独立正相关(P<0.01).OGTT试验血糖水平变化的独立相关因素依次为△I30/△G330、AUCINS、HOMA-β、HOMA-IR和腰围.HbAlc水平的独立相关因素是OGTT 3 h血糖变化. 结论 在2型糖尿病、糖耐量低减及正常等不同糖代谢状态人群中,HbAlc水平存在差异,当HbAlc>8.0%时,OGTT试验、血糖、胰岛素水平或曲线下面积均不能反映出病情差别和变化的显著性.

Research on OGTT and HbAlc levels in patients with newly diagnosed type 2 diabetes mellitus and prediabetes

Objective To explore different features and influencing factors of 75 g oral glucose tolerance test (OGTT) and glycated hemoglobin Ale (HbAlc) levels in subjects with newly diagnosed diabetes and prediabetes of natural history of type 2 diabetes. Methods All subjects were classified by OGTT into four groups: (1) normal glucose test (NGT), 31 subjects at age of (48. 4±15. 3) yrs (29-75 years old); (2) impaired fasting glucose (IFG), 33 subjects at age of (50. 8±9. 8) yrs (38-72years old) ; (3) impaired glucose tolerance test (IGT), 34 subjects at age of (54. 5±11.4) yrs (33-74years old), (4) T2DM, 117 subjects at age of (54.3 ± 14.1) yrs (29-75 years old). Glucose metabolism was evaluated by results of OGTT and HbAlc levels. The insulin secretion function and insulin resistance (IR) were evaluated by HOMA-β, △I30/△G330, area under curve of insulin (AUCINS)and HOMA-IR respectively. Results (1) Significant changes of HbAlc values among groups were as following order: T2DM(7. 41%)>IGT(5. 85%)>NGT(5.21%) (P<0. 01). HOMA-β value in T2DM, IGT and IFG decreased by 53. 1% (P<0. 01), 29.3% (P<0. 01) and 23.4% (P<0. 05)respectively as compared with NGT group. HOMA-IR value in diabetes group was 1.66-fold of NGT (P<0.01), 1. 29-fold of IFG (P<0.001) and 1.44-fold of IGT (P<0.05). (2) Only 3 h blood glucose concentration (BG) in 75 g OGTT was independently and positively correlated with HbAlc level (r=0. 71, P<0. 01). △I30/△G330 ratio was independently and negatively correlated with both 1 h and 2 h BG of OGTT (P<0.01). AUCins was positively correlated with only 3 h BG of OGTT (P<0.01). HOMA-β was independently and negatively correlated with all OGTT results except 2 h BG(P<0.01). HOMA-IR was an independently and negatively correlative factor of all OGTT results (P<0. 01 or P<0. 05). TG level was independently and positively correlated to only fasting BG (P<0. 05), and waist circumference value had an independent and positive relationship with only 1/2h BG (P<0. 01). Independently correlative factors of OGTT changes included △I30/△G330, AUCINS,HOMA-β, HOMA-IR and circumference values. Only 3 h BG was probably an independent contributor to HbAlc variation. Conclusions There are obvious HbAlc differences among T2DM,IGT and NGT patients. When HbAlc values are over 8%, no significant changes of glucose and insulin levels at 75 g glucose load test are found among subjects.