Objective: The triglyceride and glucose (TyG) index has been proposed as a simple surrogate of insulin resistance (IR) with high sensitivity as an IR index besides the well known homeostasis model assessment of IR (HOMA-IR). Limited data are reported in children. We investigated the sensitivity and specificity of TyG index in a pediatric Caucasian population, as a surrogate measure of IR and compared the results with HOMA-IR.
Methods: We enrolled 541 children (11.7±2.71 yrs). According to body mass index (BMI) chart, the subjects were divided into three groups: normal weight BMI<75th percentile, overweight BMI 75th–95th percentile, and obese>95th percentile. TyG index was calculated as (ln[fasting triglycerides(mg/dl)×fasting plasma glucose(mg/dl)/2]) and considered pathological when exceeding 7.88. HOMA-IR was calculated as (insulin×glucose)/22.5 and defined pathological whenever exceeding 97.5th percentile for age and sex.
Results: In children with overweight/obesity TyG index was higher compared to normal weight subjects (p<0.001). TyG index was correlated with BMI (p<0.001); WHtR (p<0.001), total and HDL cholesterol (p<0.001); ALT (p<0.001), blood pressure (p<0.001). A correlation between TyG index and HOMAIR (p<0.001) as well as high TyG index and pathological HOMA-IR (p<0.001) were noted. The optimal cut-off for IR was considered 7.98 (sensitivity 60%; specificity 78%; AUC 0.69).
Conclusions: TyG index is a useful and cost-effective index of IR among children and adolescents. The cutoff 7.98 may be used for IR risk screening in childhood obesity, but we recommend caution when used in other populations.
Keywords: Triglyceride glucose index; insulin resistance; children; adolescents; HOMA-IR; obesity.