title: Glycated hemoglobin and all-cause and cause-specific mortality in Singaporean Chinese without diagnosed diabetes: the Singapore Chinese Health Study.
abstract: OBJECTIVE
  Glycated hemoglobin (HbA₁c) is a robust biomarker of the preceding 2 to 3 months average blood glucose level. The aim of this study was to examine the association between HbA₁c and mortality in a cohort of Southeast Asians.
  
  
  METHODS
  Analysis of 7,388 men and women, mean age 62 years, from the Singapore Chinese Health Study who provided a blood sample at the follow-up I visit (1999-2004) and reported no history of diabetes, previous adverse cardiovascular events, or cancer. A total of 888 deaths were identified through 31 December 2011 via registry linkage. Participants represented a random study sample of potential control subjects for a nested case-control genome-wide association study of type 2 diabetes in the population. Hazard ratios (HRs) for all-cause and cause-specific mortality by six categories of HbA1c were estimated with Cox regression models.
  
  
  RESULTS
  Relative to participants with an HbA₁c of 5.4-5.6% (36-38 mmol/mol), participants with HbA₁c ≥6.5% (≥48 mmol/mol) had an increased risk of all-cause, cardiovascular, and cancer mortality during an average of 10.1 years of follow-up; HRs (95% CIs) were 1.96 (1.56-2.46), 2.63 (1.77-3.90), and 1.51 (1.04-2.18), respectively. No level of HbA1c was associated with increased risk of respiratory mortality. Levels <6.5% HbA₁c were not associated with mortality during follow-up. The results did not materially change after excluding observation of first 3 years post-blood draw.
  
  
  CONCLUSIONS
  HbA₁c levels consistent with undiagnosed type 2 diabetes (≥6.5%) are associated with an increased risk of all-cause and cause-specific mortality in Chinese men and women.
authors.affiliation: Division of Epidemiology & Community Health, School of Public Health, University of Minnesota, Minneapolis, MN.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Bancks
authors.affiliation: Division of Epidemiology & Community Health, School of Public Health, University of Minnesota, Minneapolis, MN.
authors.forename: Andrew O
authors.initials: AO
authors.lastname: Odegaard
authors.affiliation: Division of Epidemiology & Community Health, School of Public Health, University of Minnesota, Minneapolis, MN.
authors.forename: James S
authors.initials: JS
authors.lastname: Pankow
authors.affiliation: Duke-NUS Graduate Medical School Singapore, Singapore Saw Swee Hock School of Public Health, National University of Singapore, Singapore.
authors.forename: Woon-Puay
authors.initials: WP
authors.lastname: Koh
authors.affiliation: Division of Cancer Control and Population Sciences, University of Pittsburgh Cancer Institute, Pittsburgh, PA Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA.
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Yuan
authors.affiliation: Division of Epidemiology & Community Health, School of Public Health, University of Minnesota, Minneapolis, MN.
authors.forename: Myron D
authors.initials: MD
authors.lastname: Gross
authors.affiliation: Division of Epidemiology & Community Health, School of Public Health, University of Minnesota, Minneapolis, MN map@umn.edu.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Pereira
mesh_terms: D000368:Aged; D044466:Asian People / Q000706:statistics & numerical data*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002423:Cause of Death; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis / Q000401:mortality*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis*; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D012846:Singapore / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human