title: Ethnic disparity in hemoglobin A1c levels among normoglycemic offspring of parents with type 2 diabetes mellitus.
abstract: OBJECTIVE
  To investigate the racial/ethnic disparities in hemoglobin A1c levels among nondiabetic persons with similar parental history of type 2 diabetes mellitus.
  
  
  METHODS
  We studied a community-based sample of adult offspring of parents with type 2 diabetes mellitus. Measurements included anthropometry, hematology assessments, serial fasting plasma glucose, oral glucose tolerance testing, plasma insulin, hemoglobin A1c, insulin sensitivity, and β-cell function, using a homeostasis model assessment.
  
  
  RESULTS
  The study included 302 participants (135 white, 167 black). Compared with white participants, black participants had lower fasting plasma glucose levels (91.9 ± 0.51 mg/dL vs 93.6 ± 0.50 mg/dL, P = .015), lower area under the curve of plasma glucose during oral glucose tolerance testing (P = <.001), higher body mass index (31.1 ± 0.61 kg/m² vs 28.5 ± 0.57 kg/m², P = <.001), and similar insulin sensitivity and β-cell function. Hemoglobin A1c was higher in black participants than in white participants (5.68 ± 0.033% vs 5.45 ± 0.028%, P<.001). The absolute black-white difference in hemoglobin A1c level of approximately 0.22% persisted after adjusting for age, hemoglobin, hematocrit, body mass index, waist circumference, fasting plasma glucose, glucose area under the curve, and other covariates.
  
  
  CONCLUSIONS
  Among healthy offspring of parents with type 2 diabetes mellitus in this study, African American participants had higher hemoglobin A1c levels than white participants after adjusting for age, adiposity, blood glucose, and known variables. Thus, plasma glucose level is more valid than hemoglobin A1c for diagnosing prediabetes or diabetes in black persons.
authors.affiliation: Division of Endocrinology, Diabetes, and Metabolism, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Chapp-Jumbo
authors.forename: Chimaroke
authors.initials: C
authors.lastname: Edeoga
authors.forename: Jim
authors.initials: J
authors.lastname: Wan
authors.forename: Samuel
authors.initials: S
authors.lastname: Dagogo-Jack
mesh_terms: D000328:Adult; D032721:Adult Children; D001741:Black or African American; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis* / Q000208:ethnology*; D005192:Family Health / Q000208:ethnology*; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000032:analysis* / Q000378:metabolism*; D006801:Humans; D007333:Insulin Resistance / Q000208:ethnology; D050417:Insulin-Secreting Cells / Q000502:physiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D050177:Overweight / Q000150:complications / Q000208:ethnology; D011236:Prediabetic State / Q000097:blood* / Q000175:diagnosis / Q000208:ethnology / Q000378:metabolism; D013714:Tennessee; D044465:White People
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human