Abstract 17856: The Association Between Visceral Adipose Tissue Volume And Hemoglobin A1c is Not Consistent Across The Distribution of Glycemia in Middle Age Adults: A Quantile Regression Approach in the CARDIA Study
Background: Studies examining associations between visceral adipose tissue (VAT) volume and HbA1c predominantly use ordinary least squares regression to compare mean differences in HbA1c that are observed across higher levels of VAT. This approach presents little information on how the magnitude of this association differs across the distribution of HbA1c.
Objective: To quantify and compare associations between VAT and HbA1c across the distribution of HbA1c and to examine differences in the magnitude of associations by race and sex.
Methods: Coronary Artery Risk Development in Young Adults (CARDIA) is a community-based, prospective study of black and white men and women. VAT (cm3) was assessed at ages 43-55 years by computed tomography (n=2,781), HbA1c was measured by ion-exchange high-performance liquid chromatography. Quantile regression was used to estimate multiple slopes for associations between VAT and HbA1c across minimum to maximum quantiles of HbA1c accounting for age, sex, race, study center, height, smoking status and physical activity. Effect modification by race and sex was also studied. Participants taking diabetes medications were excluded from analyses.
Results: Significant positive associations were observed between VAT and HbA1c at all quantiles of HbA1c. However, effect estimates were markedly stronger at and above the 85th percentile (5.9%) of HbA1c (Figure 1). Effect estimates for the association between VAT and HbA1c were stronger among blacks than whites at all quantiles of HbA1c; no significant differences in effect estimates were observed by sex across HbA1c quantiles (data not shown).
Conclusions: Although a strong positive association exists between visceral adiposity and HbA1c in middle age adults, the magnitude of this association is markedly greater at higher levels of HbA1c. These data raise the possibility that a greater responsiveness of HbA1c per cm3 of VAT occurs in individuals with levels of HbA1c at 6.0% and higher.
- © 2013 by American Heart Association, Inc.