Differences in Hemoglobin A1c Between Hispanics/Latinos and Non-Hispanic Whites: An Analysis of the Hispanic Community Health Study/Study of Latinos and the 2007–2012 National Health and Nutrition Examination Survey

Abstract

OBJECTIVETo determine whether, after adjustment for glycemia and other selected covariates, hemoglobin A1c (HbA1c) differed among adults from six Hispanic/Latino heritage groups (Central American, Cuban, Dominican, Mexican, Puerto Rican, and South American) and between Hispanic/Latino and non-Hispanic white adults without self-reported diabetes.RESEARCH DESIGN AND METHODSWe performed a cross-sectional analysis of data from 13,083 individuals without self-reported diabetes from six Hispanic/Latino heritage groups, enrolled from 2008 to 2011 in the Hispanic Community Health Study/Study of Latinos, and 2,242 non-Hispanic white adults enrolled during the 2007–2012 cycles of the National Health and Nutrition Examination Survey. We compared HbA1c levels among Hispanics/Latinos and between Hispanics/Latinos and non-Hispanic whites before and after adjustment for age, sex, fasting (FPG) and 2-h post–oral glucose tolerance test (2hPG) glucose, anthropometric measurements, and selected biochemical and hematologic variables and after stratification by diabetes status: unrecognized diabetes (FPG ≥7.1 mmol/L or 2hPG ≥11.2 mmol/L), prediabetes (FPG 5.6–7.0 mmol/L or 2hPG 7.8–11.1 mmol/L), and normal glucose tolerance (FPG <5.6 mmol/L and 2hPG <7.8 mmol/L).RESULTSAdjusted mean HbA1c differed significantly across all seven groups (P < 0.001). Non-Hispanic whites had significantly lower HbA1c (P < 0.05) than each individual Hispanic/Latino heritage group. Upon stratification by diabetes status, statistically significant differences (P < 0.001) in adjusted mean HbA1c persisted across all seven groups.CONCLUSIONSHbA1c differs among Hispanics/Latinos of diverse heritage groups and between non-Hispanic whites and Hispanics/Latinos after adjustment for glycemia and other covariates. The clinical significance of these differences is unknown.

Diabetic by HbA1c, Normal by OGTT: A Frequent Finding in the Mexico City Diabetes Study

“…We recognize that these findings have been previously reported ( 25 , 26 ), but to our knowledge, this is the first time this issue has been explored in a low-income, elderly, urban, and predominantly obese Mexican population. Perhaps the previously-mentioned characteristics might explain the magnitude of its frequency.…”

Distribution of glycated haemoglobin and its determinants in Korean youth and young adults: a nationwide population-based study

“…Its normal range in adult populations is up to 5.7% (39 mmol/mol) 2 – 4 . HbA1c levels in adults show age-, sex-, and ethnicity-related differences, implying the need to establish reference values according to relevant factors 5 – 7 . Only a few population-based studies on HbA1c reference values have been performed to date 8 , 9 ; these have demonstrated differences in the distribution of HbA1c values based on age, sex, and ethnicity.…”

“…Considering the rapidly increasing prevalence of obesity and type 2 DM in children and adolescents, and the increasing use of HbA1c as a marker of glucose metabolism, it is important to establish normative reference values for the Korean population. Normative studies of children and adolescents, mostly conducted in the USA, showed differences in the distribution of HbA1c values based on age; values tended to be higher during adolescence 5 , 8 , 9 . The aims of the present study were to describe the normative distribution of HbA1c values and to investigate the factors associated with HbA1c values in Korean youths and young adults, using nationally representative data.…”

Diabetes risk scores for Hispanics living in the United States: A systematic review

“…A study conducted among low-income, elderly Mexicans showed disagreement between OGTT and HbA1c measurements, suggesting possible misclassification when using HbA1c alone [53]. Other studies have confirmed significantly higher levels of HbA1c for Hispanics compared to non-Hispanic whites in the U.S. [54, 55]. …”