Investigation of glycosylated hemoglobin A1c levels in 10 487 adults in Xiamen city

Abstract

Objective To study the distribution of glycosylated hemoglobin A1c (HbA1c) levels in Xiamen, and to investigate the relationship among HbA1c level and gender and age. Methods This was a cross-sectional study. 10 487 cases of physical examination individuals in Zhongshan hospital from January 2013 to April 2014 were recruited．HbA1c was measured by ARKRAY HA-8180 automatic glycosylated hemoglobin analyzer (Japan). All data were collected for analyzing the HbA1c levels in different sex and age groups, exploring the rule between HbA1c and age, and comparing the different diagnostic criteria of diabetes mellitus(DM).Differences between the two groups were compared using the Independent Samples T Test. The measurement data of multiple group were compared with single factor analysis of variance (One way ANOVA), and the comparison between two groups was performed with LSD T test. Correlation between different variables was analyzed by Pearson correlation and linear regression. Results Focused on all the 10 487 cases and 9 436 cases with HbA1c < 6.5% physical examination population,the levels of HbA1c were positively correlated with age, the linear regression equations were HbA1c (%) =0.021 2 × age (years) + 4.811 9 (r=0.348 9, P=0.000) and HbA1c (%) =0.010 9 × age (years) + 5.094 4 (r=0.4257, P=0.000)respectively; HbA1c levels in male physical examination population were significantly higher than those in females (P＜0.001),moreover, in different gender groups, HbA1c level had gradually risen with increasing age. Patients at risk for diabetes (prediabetes, 39.60%) diagnosed by the criteria of 2010 American Diabetes Association (ADA) were 2.55 times more than those diagnosed by the criteria of international expert committee (15.55%). Conclusions The HbA1c level is related to age and gender in Xiamen city. It is necessary to establish different reference intervals and DM diagnostic cut-off point. The criteria of 2010 ADA can identify more high-risk DM individuals, with is especially suitable for the physical examination screening. （Chin J Lab Med,2014,37:912-916） Key words: Hemoglobin A, glycosylated; Diabetes mellitus; Sex factors; Age factors