title: Diagnostic performance of glycated hemoglobin for diabetic retinopathy in non-diabetic older overweight/obese African-Americans.
abstract: OBJECTIVE
  Although clinicians do not routinely screen for diabetic retinopathy in non-diabetic patients, previous studies have shown that diabetic retinopathy can occur in patients with prediabetes. However, due to the limitations of glycated hemoglobin (HbA1c) in overweight/obese subjects, African-Americans and older adults, little is known about the correlation between HbA1c and diabetic retinopathy in non-diabetic older overweight/obese African-Americans. The aims of this study were to determine the association between HbA1c and diabetic retinopathy, and the optimal diagnostic threshold of HbA1c that predicts diabetic retinopathy in non-diabetic older overweight/obese African-Americans.
  
  
  METHODS
  The 2005-2012 data from the U.S. National Health and Nutrition Examination Surveys (NHANES) were utilized for this study. Prevalence odds ratios from logistic regression analyses were used to estimate risks of diabetic retinopathy across HbA1c categories, adjusting for age, sex, and hypertension. Receiver operating characteristic curve was used to determine diagnostic cutoff point of HbA1c for prevalent diabetic retinopathy.
  
  
  RESULTS
  There were gradients of increasing prevalence and odds of diabetic retinopathy with increasing HbA1c in non-diabetic overweight/obese African-Americans 50years of age and older. HbA1c cut-off point of 5.2% (AUC=.726, 95% CI=0.696-0.756) was found to maximize sensitivity [93.5%; 95% CI: 83.2-95.7] for diabetic retinopathy, though specificity [22.1%; 95% CI 19.9-32.8] was low.
  
  
  CONCLUSIONS
  Current criteria for diagnosis of prediabetes are effective in identifying many older overweight/obese African Americans with diabetic retinopathy. Based on our analysis, a lower HbA1c of 5.2% could serve as a more sensitive cutoff point for defining prediabetes in this population subgroup.
authors.affiliation: Division of Epidemiology & Biostatistics, School of Public Health, Georgia State University, Atlanta 30302, Georgia. Electronic address: iokosun@gsu.edu.
authors.forename: Ike S
authors.initials: IS
authors.lastname: Okosun
authors.affiliation: Department of Medicine, Division of General Medicine and Geriatrics, Emory University School of Medicine, Atlanta 30203, Georgia.
authors.forename: Sara
authors.initials: S
authors.lastname: Turbow
authors.affiliation: Department of Family Medicine, Mercer University School of Medicine, Macon 31210, Georgia.
authors.forename: Kris
authors.initials: K
authors.lastname: McJenkin
authors.affiliation: Department of Family Medicine, Mercer University School of Medicine, Macon 31210, Georgia.
authors.forename: Y
authors.initials: Y
authors.lastname: Monique Davis-Smith
authors.affiliation: Department of Family Medicine, Mercer University School of Medicine, Macon 31210, Georgia.
authors.forename: J Paul
authors.initials: JP
authors.lastname: Seale
mesh_terms: D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D003930:Diabetic Retinopathy / Q000453:epidemiology / Q000209:etiology* / Q000378:metabolism; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D009765:Obesity / Q000150:complications*; D016017:Odds Ratio; D050177:Overweight / Q000150:complications*; D011236:Prediabetic State / Q000453:epidemiology / Q000209:etiology* / Q000378:metabolism; D015995:Prevalence; D012372:ROC Curve; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014481:United States / Q000453:epidemiology
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin
keywords: Glycated hemoglobin; Obesity; Older age; Prediabetes