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


OBJECTIVE
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.


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


METHODS
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.
Herman
William H
WH
Internal Medicine and Epidemiology, University of Michigan, Ann Arbor, Michigan 48109, USA. wherman@umich.edu
Dungan
Kathleen M
KM
Wolffenbuttel
Bruce H R
BH
Buse
John B
JB
Fahrbach
Jessie L
JL
Jiang
Honghua
H
Martin
Sherry
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D044383:Black People; D001786:Blood Glucose / Q000378:metabolism*; D003847:Deoxyglucose / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000453:epidemiology; D005006:Ethnicity; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D044469:Racial Groups; D044465:White People
D001786:Blood Glucose; D003847:Deoxyglucose; D006442:Glycated Hemoglobin; C006584:1,5-anhydroglucitol