关键词: 糖尿病, 2型；葡萄糖耐量试验；胰岛素释放试验；血糖；胰岛素

Abstract: Background　Delayed timing of peak insulin level after glucose load is common in patients with type 2 diabetes mellitus （T2DM），which may be an important cause of postprandial hyperglycemia in this population.However，there are no studies concerning the influencing factors of delayed timing of post-load peak insulin level in T2DM patients.Objective　To investigate the influencing factors of time to peak insulin level after glucose load in T2DM patients.Methods　We selected 490 hospitalized patients with T2DM from Department of Endocrinology，Xiaogan Hospital Affiliated to Wuhan University of Science and Technology from January 2016 to June 2018.We collected their clinical data，serum HbA1c and ketone bodies levels，routine blood test and biochemistry analysis results，FPG，blood glucose levels measured again 30，60，120，180 minutes（G30 min，G60 min，G120 min，G180 min levels） after having glucose solution in a 3-hour 75 g oral glucose tolerance test （OGTT） and fasting insulin （FINS） and INS levels measured again 30，60，120，180 minutes（I30 min，I60 min，I120 min and I180 min levels） after having glucose solution in a 3-hour insulin response test，and recorded peak INS level after glucose load （Imax） and the time during which INS was at its peak （tmax）．According to tmax，we divided them into short tmax group （tmax≤90 min，n=159），medium tmax group （90 min<tmax≤135 min，n=169），and long tmax group （135 min<tmax≤180 min，n=162）．The general data，laboratory indicators，OGTT and IRN indicators of the three groups were compared.Logistic regression was used to analyze the influencing factors of tmax in patients with T2DM.Results　There were significant differences in the distribution of sex，and average course of T2DM，erythrocyte count，HbA1c concentration，G0 min，G120 min，G180 min，I60 min，I120 min and I180 min among the three groups （P<0.05）．The ratios of male to female in medium and long tmax groups were all less than that in short tmax group （P<0.016 7）．The average number of erythrocytes and HbA1c concentration in long tmax group were all less compared with those in short tmax group （P<0.05）．The average course of T2DM was shorter and average HbA1c concentration was lower in medium tmax group than those in short tmax group （P<0.05）．Long tmax group showed higher average G120 min and G180 min levels than short tmax group，and demonstrated higher average G0 min，G120 min and G180 min levels than medium tmax group （P<0.05）．Long tmax group presented lower average I60 min level but higher average I120 min and I180 min levels compared with short tmax group，and showed lower average I60 min level compared with medium tmax group （P<0.05）．Medium tmax group had higher average I120 min，and I180 min levels than short tmax group （P<0.05）．Logistic regression analysis showed that elevated G120min was a risk factor for tmax in patients with T2DM，and decreased G0 min and shorter course of T2DM were protective factors for tmax （P<0.05）．Conclusion　Elevated G120 min is an independent risk factor for delayed timing of peak insulin level after glucose load in patients with T2DM.

Key words: Diabetes mellitus, type 2；Glucose tolerance test；Insulin release test；Blood glucose；Insulin