Insulin Resistance and Associated Compensatory Responses in African-American and Hispanic Children
- From the Departments of Preventive Medicine and Physiology & Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California
OBJECTIVE—The objective of this study was to compare insulin resistance relative to body fat and the associated compensatory responses in 57 healthy children living in Los Angeles, California (14 Caucasians, 15 African-Americans, and 28 Hispanics).
RESEARCH DESIGN AND METHODS—Insulin sensitivity and acute insulin response were determined by intravenous glucose tolerance test. Insulin secretion, hepatic insulin extraction, and insulin clearance were estimated by C-peptide and insulin modeling.
RESULTS—Insulin sensitivity was significantly lower in Hispanics and African-Americans compared with Caucasian children, and acute insulin response was significantly higher in African-American children. No ethnic differences were noted in the first-phase secretion, but second-phase insulin secretion was significantly higher in Hispanic children than in African-American children (200 ± 53 vs. 289 ± 41 nmol/min; P = 0.03). The greater acute insulin response in African-Americans, despite lower secretion, was explained by a lower hepatic insulin extraction in African-Americans compared with Hispanics (36.6 ± 2.9 vs. 47.3 ± 2.2%; P = 0.0006).
CONCLUSIONS—In conclusion, Hispanic and African-American children are more insulin resistant than Caucasian children, but the associated compensatory responses are different across ethnic groups.
Address correspondence and reprint requests to Michael I. Goran, PhD, 1540 Alcazar Street, Room 208-D, Department of Preventive Medicine, University of Southern California, Los Angeles, CA 90033. E-mail:.
Received for publication 24 May 2002 and accepted in revised form 15 August 2002.
A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
See accompanying editorial on p. 2350.
- DIABETES CARE