Racial Differences in Adiponectin in Youth
Relationship to visceral fat and insulin sensitivityv
- From the Division of Pediatric Endocrinology, Metabolism and Diabetes Mellitus, Weight Management and Wellness Center, Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Address correspondence and reprint requests to Silva A. Arslanian, MD, Children’s Hospital of Pittsburgh, 3705 Fifth Avenue at DeSoto St., Pittsburgh, PA 15213. E-mail:
OBJECTIVE—The purpose of this study was to investigate 1) whether adiponectin is associated with insulin sensitivity independent of visceral adipose tissue in African-American and Caucasian youth and 2) whether adiponectin is associated with racial differences in insulin sensitivity.
RESEARCH DESIGN AND METHODS—Total body fat was measured by dual-energy X-ray absorptiometry and abdominal adipose tissue with computed tomography. Insulin sensitivity was measured by a 3-h hyperinsulinemic-euglycemic clamp.
RESULTS—Adiponectin was inversely associated (P < 0.01) with visceral adipose tissue, fasting insulin, and proinsulin and was positively related (P < 0.01) to insulin sensitivity after controlling for Tanner stage and sex independent of race. Stepwise multiple regression revealed that adiponectin was a strong independent predictor of insulin sensitivity, explaining 27% of the variance in insulin sensitivity. When subjects were categorized into tertiles of visceral adipose tissue and further low (≤50th) and high (>50th) adiponectin groups, insulin sensitivity was significantly different across the visceral adipose tissue groups (main effect, P < 0.01) in both races. However, within each visceral adipose tissue group, subjects with high adiponectin had higher insulin sensitivity (main effect, P < 0.05) than subjects with low adiponectin, independent of race. Racial differences in insulin sensitivity remained significant (P < 0.01) after controlling for leptin and visceral adipose tissue but not (P > 0.05) after additional adjustment for adiponectin.
CONCLUSIONS—Adiponectin is associated with insulin sensitivity independent of visceral adipose tissue in both African-American and Caucasian youth. Low adiponectin in African-American youth may be a biological marker that predisposes them to a greater risk of insulin resistance.
- Received May 24, 2005.
- Accepted September 17, 2005.
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