%0 Randomized Controlled Trial
%T Racial differences in measures of glycemia in the Vitamin D and Type 2 Diabetes (D2d) Study: a secondary analysis of a randomized trial.
%A LeBlanc ES
%A Pittas AG
%A Nelson J
%A Chatterjee R
%A Rasouli N
%A Rhee MK
%A Pratley RE
%A Desouza CV
%A Neff LM
%A Peters AM
%A Dagogo-Jack S
%A Hsia DS
%A  
%J BMJ Open Diabetes Res Care
%V 12
%N 1
%D 2024 Feb 12
%M 38350671
%F 4.179
%R 10.1136/bmjdrc-2023-003613
%X <B>BACKGROUND: </B>Understanding how race may influence the association between A1c and glycemia can improve diabetes screening. We sought to determine whether, for a given A1c level, glucose levels during an oral glucose tolerance test (OGTT) differed by race.<BR><B>METHODS: </B>From data collected at 22 US clinical sites, we conducted a cross-sectional study of concurrently measured A1c and OGTT and observational longitudinal follow-up of the subset with high-risk pre-diabetes. Numerical integration methods were used to calculate area under the glycemic curve (AUCglu) during OGTT and least squares regression model to estimate A1c for a given AUCglu by race, controlling for potential confounders.<BR><B>RESULTS: </B>1016 black, 2658 white, and 193 Asian persons at risk of diabetes were included in cross-sectional analysis. Of these, 2154 with high-risk pre-diabetes were followed for 2.5 years. For a given A1c level, AUCglu was lower in black versus white participants. After adjustment for potential confounders, A1c levels for a given AUCglu quintile were 0.15-0.20 and 0.02-0.19 percentage points higher in black and Asian compared with white participants, respectively (p<0.05). In longitudinal analyses, black participants were more likely to be diagnosed with diabetes by A1c than white participants (28% vs 10%, respectively; p<0.01). Black and Asian participants were less likely to be diagnosed by fasting glucose than white participants (16% vs 15% vs 37%, respectively; p<0.05). Black participants with A1c levels in the lower-level quintiles had greater increase in A1c over time compared with white participants.<BR><B>CONCLUSIONS: </B>Use of additional testing beyond A1c to screen for diabetes may better stratify diabetes risk in the diverse US population.