Racial differences in the relationship of glucose concentrations and hemoglobin A1c levels

T1D Exchange Racial Differences Study Group

Research output: Contribution to journalArticle

54 Citations (Scopus)

Abstract

Background: Debate exists as to whether the higher hemoglobin A1c (HbA1c) levels observed in black persons than in white persons are due to worse glycemic control or racial differences in the glycation of hemoglobin. Objective: To determine whether a racial difference exists in the relationship of mean glucose and HbA1c. Design: Prospective, 12-week observational study. Setting: 10 diabetes centers in the United States. Participants: 104 black persons and 104 white persons aged 8 years or older who had had type 1 diabetes for at least 2 years and had an HbA1c level of 6.0% to 12.0%. Measurements: Mean glucose concentration, measured by using continuous glucose monitoring and compared by race with HbA1c, glycated albumin, and fructosamine values. Results: The mean HbA1c level was 9.1% in black persons and 8.3% in white persons. For a given HbA1c level, the mean glucose concentration was significantly lower in black persons than in white persons (P = 0.013), which was reflected in mean HbA1c values in black persons being 0.4 percentage points (95% CI, 0.2 to 0.6 percentage points) higher than those in white persons for a given mean glucose concentration. In contrast, no significant racial differences were found in the relationship of glycated albumin and fructosamine levels with the mean glucose concentration (P > 0.20 for both comparisons). Limitation: There were too few participants with HbA1c levels less than 6.5% to generalize the results to such individuals. Conclusion: On average, HbA1c levels overestimate the mean glucose concentration in black persons compared with white persons, possibly owing to racial differences in the glycation of hemoglobin. However, because race only partially explains the observed HbA1c differences between black persons and white persons, future research should focus on identifying and modifying barriers impeding improved glycemic control in black persons with diabetes.

Original languageEnglish (US)
Pages (from-to)95-102
Number of pages8
JournalAnnals of Internal Medicine
Volume167
Issue number2
DOIs
StatePublished - Jul 18 2017

Fingerprint

Hemoglobins
Glucose
Fructosamine
Type 1 Diabetes Mellitus
Observational Studies

ASJC Scopus subject areas

  • Internal Medicine

Cite this

Racial differences in the relationship of glucose concentrations and hemoglobin A1c levels. / T1D Exchange Racial Differences Study Group.

In: Annals of Internal Medicine, Vol. 167, No. 2, 18.07.2017, p. 95-102.

Research output: Contribution to journalArticle

T1D Exchange Racial Differences Study Group. / Racial differences in the relationship of glucose concentrations and hemoglobin A1c levels. In: Annals of Internal Medicine. 2017 ; Vol. 167, No. 2. pp. 95-102.
@article{d18e8b365028488c85666149a1ed1111,
title = "Racial differences in the relationship of glucose concentrations and hemoglobin A1c levels",
abstract = "Background: Debate exists as to whether the higher hemoglobin A1c (HbA1c) levels observed in black persons than in white persons are due to worse glycemic control or racial differences in the glycation of hemoglobin. Objective: To determine whether a racial difference exists in the relationship of mean glucose and HbA1c. Design: Prospective, 12-week observational study. Setting: 10 diabetes centers in the United States. Participants: 104 black persons and 104 white persons aged 8 years or older who had had type 1 diabetes for at least 2 years and had an HbA1c level of 6.0{\%} to 12.0{\%}. Measurements: Mean glucose concentration, measured by using continuous glucose monitoring and compared by race with HbA1c, glycated albumin, and fructosamine values. Results: The mean HbA1c level was 9.1{\%} in black persons and 8.3{\%} in white persons. For a given HbA1c level, the mean glucose concentration was significantly lower in black persons than in white persons (P = 0.013), which was reflected in mean HbA1c values in black persons being 0.4 percentage points (95{\%} CI, 0.2 to 0.6 percentage points) higher than those in white persons for a given mean glucose concentration. In contrast, no significant racial differences were found in the relationship of glycated albumin and fructosamine levels with the mean glucose concentration (P > 0.20 for both comparisons). Limitation: There were too few participants with HbA1c levels less than 6.5{\%} to generalize the results to such individuals. Conclusion: On average, HbA1c levels overestimate the mean glucose concentration in black persons compared with white persons, possibly owing to racial differences in the glycation of hemoglobin. However, because race only partially explains the observed HbA1c differences between black persons and white persons, future research should focus on identifying and modifying barriers impeding improved glycemic control in black persons with diabetes.",
author = "{T1D Exchange Racial Differences Study Group} and Bergenstal, {Richard M.} and Gal, {Robin L.} and Connor, {Crystal G.} and Rose Gubitosi-Klug and Davida Kruger and Olson, {Beth A.} and Willi, {Steven M.} and Grazia Aleppo and Weinstock, {Ruth S.} and Jamie Wood and Michael Rickels and Linda DiMeglio and Bethin, {Kathleen E.} and Santica Marcovina and Andreana Tassopoulos and Sooji Lee and Elaine Massaro and Suzan Bzdick and Brian Ichihara and Eileen Markmann and Paul McGuigan and Stephanie Woerner and Michelle Ecker and Beck, {Roy W.}",
year = "2017",
month = "7",
day = "18",
doi = "10.7326/M16-2596",
language = "English (US)",
volume = "167",
pages = "95--102",
journal = "Annals of Internal Medicine",
issn = "0003-4819",
publisher = "American College of Physicians",
number = "2",

}

TY - JOUR

T1 - Racial differences in the relationship of glucose concentrations and hemoglobin A1c levels

AU - T1D Exchange Racial Differences Study Group

AU - Bergenstal, Richard M.

AU - Gal, Robin L.

AU - Connor, Crystal G.

AU - Gubitosi-Klug, Rose

AU - Kruger, Davida

AU - Olson, Beth A.

AU - Willi, Steven M.

AU - Aleppo, Grazia

AU - Weinstock, Ruth S.

AU - Wood, Jamie

AU - Rickels, Michael

AU - DiMeglio, Linda

AU - Bethin, Kathleen E.

AU - Marcovina, Santica

AU - Tassopoulos, Andreana

AU - Lee, Sooji

AU - Massaro, Elaine

AU - Bzdick, Suzan

AU - Ichihara, Brian

AU - Markmann, Eileen

AU - McGuigan, Paul

AU - Woerner, Stephanie

AU - Ecker, Michelle

AU - Beck, Roy W.

PY - 2017/7/18

Y1 - 2017/7/18

N2 - Background: Debate exists as to whether the higher hemoglobin A1c (HbA1c) levels observed in black persons than in white persons are due to worse glycemic control or racial differences in the glycation of hemoglobin. Objective: To determine whether a racial difference exists in the relationship of mean glucose and HbA1c. Design: Prospective, 12-week observational study. Setting: 10 diabetes centers in the United States. Participants: 104 black persons and 104 white persons aged 8 years or older who had had type 1 diabetes for at least 2 years and had an HbA1c level of 6.0% to 12.0%. Measurements: Mean glucose concentration, measured by using continuous glucose monitoring and compared by race with HbA1c, glycated albumin, and fructosamine values. Results: The mean HbA1c level was 9.1% in black persons and 8.3% in white persons. For a given HbA1c level, the mean glucose concentration was significantly lower in black persons than in white persons (P = 0.013), which was reflected in mean HbA1c values in black persons being 0.4 percentage points (95% CI, 0.2 to 0.6 percentage points) higher than those in white persons for a given mean glucose concentration. In contrast, no significant racial differences were found in the relationship of glycated albumin and fructosamine levels with the mean glucose concentration (P > 0.20 for both comparisons). Limitation: There were too few participants with HbA1c levels less than 6.5% to generalize the results to such individuals. Conclusion: On average, HbA1c levels overestimate the mean glucose concentration in black persons compared with white persons, possibly owing to racial differences in the glycation of hemoglobin. However, because race only partially explains the observed HbA1c differences between black persons and white persons, future research should focus on identifying and modifying barriers impeding improved glycemic control in black persons with diabetes.

AB - Background: Debate exists as to whether the higher hemoglobin A1c (HbA1c) levels observed in black persons than in white persons are due to worse glycemic control or racial differences in the glycation of hemoglobin. Objective: To determine whether a racial difference exists in the relationship of mean glucose and HbA1c. Design: Prospective, 12-week observational study. Setting: 10 diabetes centers in the United States. Participants: 104 black persons and 104 white persons aged 8 years or older who had had type 1 diabetes for at least 2 years and had an HbA1c level of 6.0% to 12.0%. Measurements: Mean glucose concentration, measured by using continuous glucose monitoring and compared by race with HbA1c, glycated albumin, and fructosamine values. Results: The mean HbA1c level was 9.1% in black persons and 8.3% in white persons. For a given HbA1c level, the mean glucose concentration was significantly lower in black persons than in white persons (P = 0.013), which was reflected in mean HbA1c values in black persons being 0.4 percentage points (95% CI, 0.2 to 0.6 percentage points) higher than those in white persons for a given mean glucose concentration. In contrast, no significant racial differences were found in the relationship of glycated albumin and fructosamine levels with the mean glucose concentration (P > 0.20 for both comparisons). Limitation: There were too few participants with HbA1c levels less than 6.5% to generalize the results to such individuals. Conclusion: On average, HbA1c levels overestimate the mean glucose concentration in black persons compared with white persons, possibly owing to racial differences in the glycation of hemoglobin. However, because race only partially explains the observed HbA1c differences between black persons and white persons, future research should focus on identifying and modifying barriers impeding improved glycemic control in black persons with diabetes.

UR - http://www.scopus.com/inward/record.url?scp=85025067894&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85025067894&partnerID=8YFLogxK

U2 - 10.7326/M16-2596

DO - 10.7326/M16-2596

M3 - Article

VL - 167

SP - 95

EP - 102

JO - Annals of Internal Medicine

JF - Annals of Internal Medicine

SN - 0003-4819

IS - 2

ER -