Racial differences in the correlation between gonadal androgens and serum insulin levels.
OBJECTIVE
We previously demonstrated a direct correlation between serum insulin levels and gonadal androgens (testosterone and androstenedione) in a group of obese hyperandrogenic predominantly black women. Subsequent work by others in predominantly white women showed conflicting results. To examine these potentially important racial differences further, 14 premenopausal females from each ethnic group, of similar age, BMI, and waist-to-hip ratio, were studied.


METHODS
We measured baseline gonadal androgens, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), and leutinizing hormone (LH)/follicle-stimulating hormone ratio. Serum glucose, insulin, and C-peptide were measured at baseline and during a 2-h oral glucose tolerance test (area under the curve [AUC]). Insulin sensitivity was measured by glucose decrement during the first 15 min of an intravenous insulin tolerance test.


RESULTS
Simple correlation analysis revealed a significant direct correlation in blacks (but not whites) between gonadal androgens and AUC for glucose, insulin, and C-peptide. Race-by-covariate interaction models reinforced the simple correlation finding. Cholesterol level was also correlated to all androgens in blacks, but not in whites. We also found that whites had higher serum triglycerides and greater AUC glucose than blacks.


CONCLUSIONS
We conclude that there is a significant direct correlation between gonadal androgens and stimulated glucose, insulin, and C-peptide in blacks but not in whites. Thus, the previously reported direct correlation between gonadal hyperandrogenism and hyperinsulinemia may be a race-dependent phenomenon, hitherto an unreported observation. The implications of these findings are discussed.
Kitabchi
A E
AE
Department of Medicine, The Clinical Research Center, University of Tennessee, Memphis 38163, USA. akitabchi@utmeml.utmem.edu
Imseis
R E
RE
Bush
A J
AJ
Williams-Cleaves
B
B
Pourmotabbed
G
G
D000293:Adolescent; D000328:Adult; D000735:Androstenedione / Q000097:blood*; D044383:Black People / Q000235:genetics*; D015992:Body Mass Index; D003687:Dehydroepiandrosterone / Q000097:blood; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D003710:Demography; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood*; D007986:Luteinizing Hormone / Q000097:blood; D017697:Premenopause; D013739:Testosterone / Q000097:blood*; D044465:White People / Q000235:genetics*
D007328:Insulin; D013739:Testosterone; D000735:Androstenedione; D003687:Dehydroepiandrosterone; D019314:Dehydroepiandrosterone Sulfate; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone