title: Extreme Levels of HbA1c Increase Incident ESRD Risk in Chinese Patients with Type 2 Diabetes: Competing Risk Analysis in National Cohort of Taiwan Diabetes Study.
abstract: BACKGROUND
  Whether HbA1c is a predictor of end-stage renal disease (ESRD) in type 2 diabetes patients remains unclear. This study evaluated relationship between HbA1c and ESRD in Chinese patients with type 2 diabetes.
  
  
  METHODS
  Patients aged ≥ 30 years who were free of ESRD (n = 51 681) were included from National Diabetes Care Management Program from 2002-2003. Extended Cox proportional hazard model with competing risk of death served to evaluate association between HbA1c level and ESRD.
  
  
  RESULTS
  A total of 2613 (5.06%) people developed ESRD during a follow-up period of 8.1 years. Overall incidence rate of ESRD was 6.26 per 1000 person-years. Patients with high levels of HbA1c had a high incidence rate of ESRD, from 4.29 for HbA1c of  6.0%-6.9% to 10.33 for HbA1c ≥ 10.0% per 1000 person-years. Patients with HbA1c < 6.0% particularly had a slightly higher ESRD incidence (4.34 per 1000 person-years) than those with HbA1c  of 6.0%-6.9%. A J-shaped relationship between HbA1c level and ESRD risk was observed. After adjustment, patients with HbA1c < 6.0% and ≥ 10.0% exhibited an increased risk of ESRD (HR: 1.99, 95% CI: 1.62-2.44; HR: 4.42, 95% CI: 3.80-5.14, respectively) compared with those with HbA1c of 6.0%-6.9%.
  
  
  CONCLUSIONS
  Diabetes care has focused on preventing hyperglycemia, but not hypoglycemia. Our study revealed that HbA1c level ≥ 7.0% was linked with increased ESRD risk in type 2 diabetes patients, and that HbA1c < 6.0% also had the potential to increase ESRD risk. Our study provides epidemiological evidence that appropriate glycemic control is essential for diabetes care to meet HbA1c targets and improve outcomes without increasing the risk to this population. Clinicians need to pay attention to HbA1c results on diabetic nephropathy.
authors.affiliation: Department of Public Health, College of Public Health, China Medical University, Taichung, Taiwan.
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Liao
authors.affiliation: Department of Medical Research, China Medical University Hospital, Taichung, Taiwan; School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Chia-Ing
authors.initials: CI
authors.lastname: Li
authors.affiliation: Department of Medical Research, China Medical University Hospital, Taichung, Taiwan; School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan; Department of Family Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Chiu-Shong
authors.initials: CS
authors.lastname: Liu
authors.affiliation: School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan; Kidney Institute and Division of Nephrology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Chiu-Ching
authors.initials: CC
authors.lastname: Huang
authors.affiliation: School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan; Department of Family Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Wen-Yuan
authors.initials: WY
authors.lastname: Lin
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan; Research Center for Chinese Medicine & Acupuncture, China Medical University, Taichung, Taiwan.
authors.forename: Jen-Huai
authors.initials: JH
authors.lastname: Chiang
authors.affiliation: Department of Medical Research, China Medical University Hospital, Taichung, Taiwan; School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan; Department of Family Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Cheng-Chieh
authors.initials: CC
authors.lastname: Lin
authors.affiliation: Graduate Institute of Biostatistics, College of Public Health, China Medical University, Taichung, Taiwan; Department of Healthcare Administration, College of Health Science, Asia University, Taichung, Taiwan.
authors.forename: Tsai-Chung
authors.initials: TC
authors.lastname: Li
mesh_terms: D000328:Adult; D044466:Asian People; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications* / Q000453:epidemiology*; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000097:blood / Q000453:epidemiology* / Q000209:etiology*; D008137:Longitudinal Studies; D008875:Middle Aged; D016016:Proportional Hazards Models; D018570:Risk Assessment; D013624:Taiwan / Q000453:epidemiology
chemical_list: D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human