title: HbA1c and all-cause mortality risk among patients with type 2 diabetes.
abstract: BACKGROUND
  Several prospective studies have evaluated the association between glycosylated hemoglobin (HbA1c) and death risk among diabetic patients. However, the results have been inconsistent.
  
  
  METHODS
  We performed a prospective study which included 13,334 men and 21,927 women with type 2 diabetes. Cox proportional hazards regression models were used to estimate the association of different levels of HbA1c with all-cause mortality.
  
  
  RESULTS
  During a mean follow up of 8.7 years, 4199 (2082 men and 2117 women) patients died. The multivariable-adjusted hazard ratios (HRs) of all-cause mortality associated with different levels of HbA1c at baseline (<6.0%, 6.0-6.9% [reference], 7.0-7.9, 8.0-8.9%, 9.0-9.9%, 10.0-10.9%, and ≥11.0%) were 1.06, 1.00, 1.10, 0.93, 1.26, 1.18 and 1.31 (Pnon-linear=0.008) for men, and 1.21, 1.00, 1.01, 1.08, 1.30, 1.30 and 1.74 (Pnon-linear<0.001) for women, respectively. The J-shaped association of HbA1c with all-cause mortality was confirmed among African American and white diabetic patients, patients who were more than 50 years old, never smoked or used insulin. When we used an updated mean value of HbA1c, the J-shaped association of HbA1c with the risk of all-cause mortality did not change.
  
  
  CONCLUSIONS
  Our study demonstrated a J-shaped association between HbA1c and the risk of all-cause mortality among men and women with type 2 diabetes. Both high and low levels of HbA1c were associated with an increased risk of all-cause mortality.
authors.affiliation: Pennington Biomedical Research Center, Baton Rouge, LA, USA; Tianjin Women's and Children's Health Center, Tianjin, China.
authors.forename: Weiqin
authors.initials: W
authors.lastname: Li
authors.affiliation: Pennington Biomedical Research Center, Baton Rouge, LA, USA.
authors.forename: Peter T
authors.initials: PT
authors.lastname: Katzmarzyk
authors.affiliation: Pennington Biomedical Research Center, Baton Rouge, LA, USA.
authors.forename: Ronald
authors.initials: R
authors.lastname: Horswell
authors.affiliation: Pennington Biomedical Research Center, Baton Rouge, LA, USA.
authors.forename: Yujie
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Louisiana State University Health Center, Baton Rouge, LA, USA.
authors.forename: Jolene
authors.initials: J
authors.lastname: Johnson
authors.affiliation: Pennington Biomedical Research Center, Baton Rouge, LA, USA. Electronic address: gang.hu@pbrc.edu.
authors.forename: Gang
authors.initials: G
authors.lastname: Hu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000175:diagnosis / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: Cohort study; HbA1c; Mortality; Type 2 diabetes