Racial and ethnic differences in mean plasma glucose, hemoglobin A1c, and 1,5-anhydroglucitol in over 2000 patients with type 2 diabetes

J Clin Endocrinol Metab. 2009 May;94(5):1689-94. doi: 10.1210/jc.2008-1940. Epub 2009 Mar 10.

Abstract

Content: Recent studies have reported hemoglobin A(1c) (A1c) differences across racial/ethnic groups. Our diverse population allows for further investigation of potential differences in measurements of glycemia.

Objectives: Our objectives were to describe and explore baseline racial/ethnic differences in self-monitored plasma glucose profiles, A1c, and 1,5-anhydroglucitol (1,5-AG) in patients with type 2 diabetes enrolled in the Assessing DURAbility of Basal vs. Lispro Mix 75/25 Insulin Efficacy trial.

Design, setting, patients: The trial enrolled 2094 patients with type 2 diabetes, ages 30-80 yr, from 11 countries.

Main outcome measures: Estimated mean plasma glucose (MPG), A1c, and 1,5-AG were compared among racial/ethnic groups before and after adjusting for factors affecting glycemia: age, sex, duration of diabetes, body mass index, and MPG.

Results: Baseline estimated MPG +/- sd was 220.0 +/- 82.0 mg/dl, mean A1c was 9.0 +/- 1.3%, and 1,5-AG was 5.0 +/- 4.1microg/ml. Estimated MPG did not differ between Caucasian and non-Caucasian groups. A1c was higher in Hispanics (9.4 +/- 1.4%; P < 0.001), Asians (9.2 +/- 1.4%; P < 0.01), and patients of other racial/ethnic groups (9.7 +/- 1.5%; P < 0.001) compared with Caucasians (8.9 +/- 1.2%). Paradoxically, 1,5-AG was higher for Asian (5.7 +/- 4.6 microg/ml) and African patients (6.2 +/- 5.4 microg/ml) vs. Caucasians (4.9 +/- 3.9 microg/ml) (P < 0.01). After adjusting for factors affecting glycemia, A1c was higher (all P <or= 0.002) in Hispanics, Asians, Africans, and patients of other racial/ethnic groups, and 1,5-AG was higher in Asian and African patients (P < 0.001) vs. Caucasians.

Conclusions: There were differences in A1c and 1,5-AG, but not MPG, among racial/ethnic groups. Comparisons of glycemia across racial/ethnic groups using these parameters may be problematic due to inherent biological variability and methodological issues.

Publication types

  • Comparative Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • African Continental Ancestry Group
  • Aged
  • Aged, 80 and over
  • Asian Continental Ancestry Group
  • Blood Glucose / metabolism*
  • Continental Population Groups
  • Deoxyglucose / blood*
  • Diabetes Mellitus, Type 2 / blood*
  • Diabetes Mellitus, Type 2 / epidemiology
  • Ethnic Groups
  • European Continental Ancestry Group
  • Female
  • Glycated Hemoglobin A / metabolism*
  • Humans
  • Male
  • Middle Aged

Substances

  • Blood Glucose
  • Glycated Hemoglobin A
  • 1,5-anhydroglucitol
  • Deoxyglucose