Insulin-like growth factor binding protein-1 is independently affected by ethnicity, insulin sensitivity, and leptin in healthy, glucose-tolerant young men.
We examined the relationships among IGF binding protein (IGFBP)-1, insulin sensitivity, and leptin in different ethnic groups (Asian Indians, Chinese, and Caucasians) using the euglycemic hyperinsulinemic clamp. Ten healthy, young and nondiabetic subjects of each ethnic group, matched for body mass index, age, and physical activity were studied. A euglycemic clamp was performed on all subjects. IGFBP-1, insulin, and leptin were measured after fasting and during the clamp. Fasting IGFBP-1 concentration was highest in Chinese (P = 0.027). Asian Indians had the lowest insulin sensitivity index (P = 0.006). The ratio of insulin to IGFBP-1 at fasting and throughout the euglycemic clamp was higher in Asian Indians. Fasting IGFBP-1 had a strong negative correlation with fasting leptin levels (r = -0.715, P = 0.001). Multiple linear regression demonstrated that fasting insulin, leptin, ethnicity, and insulin sensitivity were significant predictors for fasting IGFBP-1. IGFBP-1 is independently determined by ethnicity, insulin sensitivity, and leptin in glucose-tolerant men. The presence of relative insulin resistance and low fasting IGFBP-1 levels in Asian Indians may contribute to their higher risk of developing diabetes and cardiovascular disease.
Liew
Choon F
CF
Department of Medicine, National University of Singapore, 5 Lower Kent Ridge Road, Singapore.
Wise
Stephen D
SD
Yeo
Kwee P
KP
Lee
Kok O
KO
D000328:Adult; D044466:Asian People; D002318:Cardiovascular Diseases / Q000208:ethnology; D003920:Diabetes Mellitus / Q000208:ethnology; D005215:Fasting; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood*; D020738:Leptin / Q000097:blood*; D008297:Male; D012307:Risk Factors; D044465:White People
D018970:Insulin-Like Growth Factor Binding Protein 1; D020738:Leptin