Racial differences in adiponectin in youth: relationship to visceral fat and insulin sensitivity.
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.


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 (< or = 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.
Lee
SoJung
S
Division of Pediatric Endocrinology, Metabolism and Diabetes Mellitus, Weight Management and Wellness Center, Children's Hospital of Pittsburgh, 3705 Fifth Avenue at DeSoto St., Pittsburgh, Pennsylvania 15213, USA.
Bacha
Fida
F
Gungor
Neslihan
N
Arslanian
Silva A
SA
D052242:Adiponectin / Q000097:blood*; D000273:Adipose Tissue / Q000033:anatomy & histology*; D000293:Adolescent; D044383:Black People; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D015309:Glucose Clamp Technique; D006801:Humans; D007262:Infusions, Intravenous; D007328:Insulin / Q000008:administration & dosage / Q000494:pharmacology; D020738:Leptin / Q000097:blood; D044469:Racial Groups; D012044:Regression Analysis; D014481:United States; D014781:Viscera; D044465:White People; D001741:Black or African American
D052242:Adiponectin; D001786:Blood Glucose; D007328:Insulin; D020738:Leptin