title: The change points of HbA(1C) for detection of retinopathy in Chinese type 2 diabetic patients.
abstract: OBJECTIVE
  To investigate the change points of HbA(1C) for detection of retinopathy in Chinese type 2 diabetic patients.
  
  
  METHODS
  This cross-sectional investigation included 992 diagnosed type 2 diabetic patients, who received non-mydriatic digital fundus photography examination. Joinpoint regression software was adopted to identify the change points of HbA(1C) in association with retinopathy prevalence.
  
  
  RESULTS
  The mean age of all patients was 59.1 ± 8.4 years and the duration of diabetes was 5.5 (95% CI: 5.2-5.9) years. The prevalence of retinopathy was 10.3% in total, and 4.1%, 7.4% and 19.6% in patients with different diabetes duration of ≤ 5 years, 5-10 years and >10 years, respectively. The change point of HbA(1C) was 6.5% (95%CI 5.8-7.5%), at which retinopathy prevalence began to rise sharply. Furthermore, in subjects with diabetes duration ≤ 5 years, 5-10 years and >10 years, the change points of HbA(1C) were 8.1% (95%CI 7.9-8.3%), 6.1% (95%CI 5.7-6.8%), 5.6% (95%CI 5.1-8.1%) for detection of retinopathy, respectively.
  
  
  CONCLUSIONS
  The steepest increase in retinopathy prevalence occurred when HbA(1C) reached 6.5%. However, the duration of diabetes should be taken into concern, when using the change points of HbA(1C) for detection of retinopathy in diabetic patients.
authors.affiliation: Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Shanghai, China.
authors.forename: Jia-Ning
authors.initials: JN
authors.lastname: Hou
authors.forename: Yu-Fang
authors.initials: YF
authors.lastname: Bi
authors.forename: Min
authors.initials: M
authors.lastname: Xu
authors.forename: Yun
authors.initials: Y
authors.lastname: Huang
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: Li
authors.forename: Wei-Qing
authors.initials: WQ
authors.lastname: Wang
authors.forename: Yu-Hong
authors.initials: YH
authors.lastname: Chen
authors.forename: Guang
authors.initials: G
authors.lastname: Ning
mesh_terms: D000368:Aged; D044466:Asian People; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000453:epidemiology; D003930:Diabetic Retinopathy / Q000175:diagnosis* / Q000453:epidemiology; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D008875:Middle Aged; D015995:Prevalence; D012984:Software
chemical_list: D006442:Glycated Hemoglobin