Insulin resistance syndrome in childhood: Associations of the euglycemic insulin clamp and fasting insulin with fatness and other risk factors

Objective: Our objective was to describe in children the relation of fatnes s and insulin resistance to the risk factors associated with the insulin re sistance syndrome and to compare fasting insulin with the euglycemic insuli n clamp as a measure of insulin resistance in children. Study design: This was a random selection of participants after blood press ure screening of 12,043 students in the fifth through eighth grades. Euglyc emic insulin clamp studies with an insulin infusion rate of 1 in U/kg/min a nd a variable infusion of 20% glucose to maintain euglycemia, that is, plas ma glucose at 5.6 mmol/L. Insulin sensitivity (M-lbm) is defined as the amo unt of glucose required to maintain euglycemia (milligrams of glucose infus ed per kilogram lean body mass per minute). Results: Body mass index was significantly correlated with fasting insulin and significantly inversely correlated with M-lbm. Fasting Insulin was sign ificantly correlated with systolic blood pressure in both sexes, all lipids , except high-density lipoprotein-cholesterol in males and triglycerides an d high-density lipoprotein-cholesterol in females, but after adjustment was done for bode, mass index, it was significantly related only to triglyceri des. M-lbm was significantly correlated only with triglycerides and high-de nsity lipoprotein-cholesterol, and this did not change after adjustment was done for body mass index. A clustering effect for the risk factors was see n in children in the lowest quart tile of M-lbm (highest degree of insulin resistance) compared with children in the highest quartile of M-lbm (lowest degree ofinsulin resistance). Conclusions: As defined by M-lbm, there is an early association of insulin resistance, independent of body fat, with the risk factors. There is a sign ificant relation between fasting insulin, as an estimate of insulin resista nce, and the risk factors, but this is significantly influenced by body fat ness. The clustering of risk factors according to level of Mlbm suggests th at adult cardiovascular disease is more likely to develop in children with the greatest degree of insulin resistance.