Although black and white differences in hemoglobin A1c (HbA1c) values are well established, recent studies suggest that the difference might not reflect differences in glycemia.
To investigate racial disparities in glycemic markers, including those that reflect biological processes independent of hemoglobin glycation and erythrocyte turnover.
1376 nondiabetic and 343 diabetic adults in a substudy of the Atherosclerosis Risk in Communities Study.
Hemoglobin A1c, fasting glucose, glycated albumin, fructosamine, and 1,5-anhydroglucitol levels.
In persons with and without diabetes, black persons had significantly higher values of HbA1c, glycated albumin, and fructosamine levels compared with white persons before and after adjustment for covariates and fasting glucose concentration. Serum 1,5-anhydroglucitol, which is reduced in the setting of hyperglycemia-induced glycosuria, was lower in black persons compared with white persons, although this difference was statistically significant only in nondiabetic adults.
The design was cross-sectional, a limited number of participants with a history of diabetes were included, and the study did not include integrated measures of circulating nonfasting glycemia
Black and white differences in glycated albumin, fructosamine, and 1,5-anhydroglucitol parallel black and white differences in HbA1c values. Racial differences in hemoglobin glycation and erythrocyte turnover cannot explain racial disparities in these serum markers. The possibility that black persons have systematically higher levels of nonfasting glycemia deserves further study.