[A prospective study of relationship between glycated hemoglobin level and occurrence of diabetes complications in patients with type 2 diabetes mellitus in 11 provinces of China].

Abstract

Objective: To investigate the relationship between glycated hemoglobin (HbA1c) level and the occurrence of diabetes complications in patients with type 2 diabetes mellitus in 11 provinces in China. Methods: A total of 4 832 patients with type 2 diabetes mellitus from 60 surveillance sites in 11 provinces where national surveillance for chronic diseases and risk factors was conducted in 2010 were selected as the study participants, and a follow-up survey was conducted in 3 516 persons from 2016 to 2017, finally 3 427 patients were included in the analysis after excluding those data exception and incomplete data. Cox proportional risk regression model was used to evalaute the association between HbA1c level and the risk for diabetes complications (macroangiopathy, microangiopathy and diabetic foot), and subgroup analyses were conducted according to the baseline characteristics of the study participants, such as age, gender and smoking status. Results: A total of 3 427 study participants were included in final analysis of the follow up for an average of 6.2 years, in whom 395 suffered from macroangiopathy, 226 suffered from microangiopathy, and 57 suffered from diabetic foot later during the follow-up period. After adjusting for relevant confounders, using the HbA1c <7.0% as a reference, there was no increased risk for macrovascular lesions in the those with HbA1c levels of 7.0%-, 7.5%-, 8.0%-8.4%, and the risk for macrovascular lesions increased by 38% in those with HbA1c ≥8.5% (HR=1.38,95%CI:1.06-1.80); the risk for microangiopathies increased by 131% (HR=2.31,95%CI:1.46-3.65), 206%(HR=3.06,95%CI:1.91-4.90) and 208% (HR=3.08,95%CI:2.20-4.30) in those with HbA1c levels of 7.5%-, 8.0%-, ≥8.5%, respectively; and the risk for diabetic foot increased by 253% (HR=3.53, 95%CI: 1.89-6.59) in those with HbA1c level ≥8.5%. Subgroup analyses revealed an effect modifying effect of different diabetes diagnosis situations (previously diagnosed and newly diagnosed) on HbA1c level and the risk for microangiopathy. Conclusions: HbA1c level ≥7.5% would increase the risk for microangiopathy in patients with type 2 diabetes mellitus, the higher the level, the higher the risk, and HbA1c level ≥8.5% would increase the risk for macrovascular lesions and diabetic foot. It is necessary to strengthen the health education in diabetic patients to improve their awareness of blood glucose management and the importance of HbA1c level control to effectively reduce or delay the diabetes complications.