title: Influence of glycosylated hemoglobin on sight-threatening diabetic retinopathy: a population-based study.
abstract: OBJECTIVE
  To evaluate the role of glycosylated hemoglobin (HbA1c) on the occurrence of sight-threatening diabetic retinopathy (STDR) in urban Chennai, Tamil Nadu, India.
  
  
  METHODS
  A total of 5999 individuals were enumerated from the Chennai metropolis. Of these, 1414 subjects with diabetes were included for data analysis in the study. STDR or non-STDR groups were classified based on the fundus photographs. HbA1c was measured (Bio-Rad DiaSTAT™ HbA1c Reagent Kit) by the liquid chromatography technique.
  
  
  RESULTS
  A statistically significant difference (p < 0.05) was noted in the duration of diabetes, gender, body mass index, HbA1c, micro- and macro-albuminuria between both non-STDR and STDR groups as compared to the no-diabetic retinopathy (DR) group. On multivariate analysis, HbA1c (non-STDR: odd's ratio OR = 1.23; 95% confidence interval CI = 1.15-1.32; p < 0.0001; STDR: OR = 1.31 95% CI = 1.14-1.52; p < 0.0001) was found to be significantly associated with non-STDR and STDR when compared with the no-DR group. The Receiver Operating Characteristic analysis showed that the cut-off value of 8.0 had 75.6% sensitivity and 58.2% specificity with 64.9% maximum area under the curve.
  
  
  CONCLUSIONS
  HbA1c value >8.0% was significantly related with STDR. In a screening programme, the cut-off value of HbA1c >8.0% provided a maximum yield of STDR.
authors.affiliation: Shri Bhagwan Mahavir Vitreoretinal Services, 18 College Road, Sankara Nethralaya, Chennai 600 006, Tamil Nadu, India.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Raman
authors.forename: Aditya
authors.initials: A
authors.lastname: Verma
authors.forename: Swakshyar Saumya
authors.initials: SS
authors.lastname: Pal
authors.forename: Aditi
authors.initials: A
authors.lastname: Gupta
authors.forename: K
authors.initials: K
authors.lastname: Vaitheeswaran
authors.forename: Tarun
authors.initials: T
authors.lastname: Sharma
mesh_terms: D000368:Aged; D000419:Albuminuria / Q000378:metabolism; D003930:Diabetic Retinopathy / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D014792:Visual Acuity
chemical_list: D006442:Glycated Hemoglobin