Diabetes Care, Vol 20, Issue 11 1670-1676, Copyright © 1997 by American Diabetes Association
Insulin response in a triethnic population: effects of sex, ethnic origin, and body fat. Miami Community Health Study
RP Donahue, JA Bean, RA Donahue, RB Goldberg and RJ Prineas
University of Miami School of Medicine, Department of Epidemiology and Public Health, Florida, USA. rdonahue@ubmedf.buffalo.edu
OBJECTIVE: To assess sex and ethnic differences in hyperinsulinemia/insulin
resistance and to examine the impact of percent body fat on such
differences. RESEARCH DESIGN AND METHODS: A cross-sectional epidemiological
study was performed in a normoglycemic population of African-Americans (n =
159), Cuban Americans (n = 128), and non-Hispanic whites (n = 207) who
resided in Dade County, Florida, from 1990 to 1995. The insulin area under
the curve (AUC) in response to a standard 75-g oral glucose tolerance test
(OGTT) was used as an indicator of hyperinsulinemia/insulin resistance.
Analysis of covariance was performed to compare sex and ethnic differences
in the insulin AUC. Multiple linear regression was used to evaluate the
independent correlates of the insulin AUC. RESULTS: After covariate
adjustment for percent body fat, men displayed a significantly higher
insulin AUC than did women (P < 0.001). African-Americans and
Cuban-Americans each had a significantly higher insulin AUC than did
non-Hispanic white participants (P = 0.01). Alcohol consumption was
inversely related to AUC (P = 0.04). CONCLUSIONS: Despite the greater
percentage of body fat in women, the insulin AUC was similar in women and
men. After adjustment for the sex difference in percent body fat, women
displayed a lower insulin AUC than did men, indicating enhanced insulin
sensitivity. These differences by sex and ethnicity in insulin resistance
are consistent with established differences in heart-disease risk (i.e.,
higher in men and African-Americans) and suggest that
hyperinsulinemia/insulin resistance may partly underlie such differences.