HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Fan, J. Articles by Barrett-Connor, E. Search for Related Content PubMed PubMed Citation Articles by Fan, J. Articles by Barrett-Connor, E. Social Bookmarking                What's this?

Bimodality of 2-h Plasma Glucose Distributions in Whites

The Rancho Bernardo Study

¹ Department of Mathematics and Statistics, San Diego State University, San Diego, California
² Department of Family and Preventive Medicine, University of California San Diego, La Jolla, California

Address correspondence and reprint requests to Elizabeth Barrett-Connor, MD, Department of Family and Preventive Medicine, University of California, San Diego, 9500 Gilman Dr., MC 0607, La Jolla, CA 92093-0607. E-mail: ebarrettconnor{at}ucsd.edu

OBJECTIVE—Several studies have shown a bimodal curve in the distribution of glucose in populations with a high prevalence of type 2 diabetes, but bimodality has not been reported among whites of Northern European ancestry. It is not clear whether this difference reflects the lower prevalence of diabetes, obscuring a second mode, or implies a more fundamental difference between whites and nonwhites. We investigate this issue by studying glucose distributions in older white patients.

RESEARCH DESIGN AND METHODS—A study of diabetes was conducted among older community-dwelling white residents of a suburban Southern California community between 1984 and 1987. Two-hour plasma glucose data were collected from 2,326 older white men and women aged 23–92. To investigate bimodality of glucose distributions, we fit unimodal and bimodal normal models to 2-h plasma glucose concentrations transformed by the Box-Cox family of transformations.

RESULTS—We found that the bimodal normal mixture model fit the data significantly better than the unimodal skewed distribution model for both sexes and all age-groups except those 80 years. The cut points separating the two modes were generally within the 11.1- to 13.6-mmol/l range.

CONCLUSIONS—The bimodality of glucose distributions among whites, combined with previous findings, indicates that this phenomenon may be universal. A smaller second mode in our study compared with other studies suggests that whites have diabetes susceptibility but may require more obesity to demonstrate it. With increasing obesity in the U.S., the predicted epidemic of diabetes may affect all ethnic groups including whites.

CiteULike    Del.icio.us    Digg    Reddit    Technorati    What's this?