The analysis of glycated hemoglobin(HbA_1c) values in 174 normal glucose tolerance population

Objective To analyze the results of glycated hemoglobin measurement and related factors in normal glucose tolerance population.Methods A 75 g oral glucose tolerance test(OGTT) was administered to health check-up subjects and diabetes screening population.HbA_1c detecting,regular hemotology test,urine test,fasting plasma glucose(FPG),2 hours plasma glucose(2hPG) and blood biochemical test were conducted.Anthropometric measurements were performed to all the subjects.A total of 174 individuals with normal FPG and 2hPG were included for data analysis.Linear regression method was used to analyze the correlation of HbA_1c to age,FPG and 2hPG,respectively.Reference range of HbA_1c was determined by 95%confidence interval for the mean HbA_1c.All the subjects were divided into two groups:HbA_1c≤5.6%group and≥5.7～6.4%group,and the clinical characteristics were compared between the two groups.Results HbA_1c was normally distributed in our study population.The mean of HbA_1c was 5.62%(SD 0.38%).The reference range was 4.88%～6.36%. There was no difference in HbA_1c between male and female subjects(P0.05).While a significant difference in HbA_1c and FPG was found between age groups.Age,FPG,2hPG and TG were statistically different(P0.01 or P0.05) between HbA_1c≤5.6%and≥5.7%～6.4%groups.Conclusions Each laboratory should make its own reference range of HbA_1c test.HbA_1c is positively correlated with age and FPG in the population with normal glucose tolerance.The non-diabetic population with high risk HbA_1c value should monitor FPG,2hPG and serum triglyceride more frequently.