Use of markers of dyslipidemia to identify overweight youth with insulin resistance.

CONTEXT: Markers to identify overweight youth with insulin resistance are of clinical importance.
OBJECTIVE: To determine if markers of dyslipidemia could identify overweight adolescents with insulin resistance. SETTING, PARTICIPANTS, AND STUDY
DESIGN: We retrospectively examined the association between markers of dyslipidemia and insulin resistance in 35 overweight [body mass index (BMI) of > or =95th percentile], white adolescents [mean age 13.5 +/- (SD) 1.6 yr] who had participated in hyperinsulinemic-euglycemic clamp studies to evaluate insulin action. Total body fat was measured by dual-energy X-ray absorptiometry and abdominal fat with computed tomography. Using receiver-operating curves, cut-points for triglyceride (TG)/high-density lipoprotein (HDL) and TG level to identify overweight individuals in the lowest tertile for insulin sensitivity were determined. MAIN OUTCOME MEASURE: Difference in the values for insulin sensitivity among the groups.
RESULTS: Of the markers examined (TG, TG/HDL, adiponectin, measures of adiposity and fasting insulin), fasting insulin was the strongest correlate of insulin sensitivity (r = 0.87, p < 0.001). Youth with TG/HDL level > or =3 had lower insulin sensitivity (50% lower median values, p < 0.01) and higher visceral fat (p < 0.05) despite BMI comparable to that of youth with TG/HDL level <3. Youth with TG/HDL > or =3 had a sensitivity of 61% and specificity of 82% for identifying participants with the greatest degree of insulin resistance.
CONCLUSIONS: TG and TG/HDL are easily obtained markers associated with insulin resistance. Further research is needed to determine if a constellation of clinical findings, such as components of the metabolic syndrome along with other metabolic markers including adiponectin, better predicts insulin resistance in overweight youth.