Distribution and cutoff points of fasting insulin in Asian Indian adolescents and their association with metabolic syndrome.

AIM To evaluate the levels and appropriate cutoff points of fasting insulin, and their association with the metabolic syndrome (MS) in Asian Indian adolescents. METHODS This cross-sectional, population based study included 948 (527 males & 421 females) adolescent subjects aged 14-19 years selected randomly from New Delhi, India. Cutoff points of fasting insulin were defined using Receiver Operating Characteristics curve analysis against overweight, abdominal obesity and high subscapular skinfold thickness. The MS was defined according to NCEP, ATP III and IDF criteria using age-, gender- and ethnicity-specific cutoff points. RESULTS Fasting insulin levels peaked at 16 y and reduced subsequently in both genders. The derived cutoff points for fasting insulin (pmol/L) were: 14-15 y- 128.5 and 164.8; 16-17 y- 126.1 and 152.8; 18-19 y- 121.2 and 162.4 in males and females, respectively. Prevalence of fasting hyperinsulinemia (39.1%) and MS (NCEP 2.2%, IDF 1.5%) was highest in age group 16-17 years. CONCLUSION The data from this first study describing the distribution and cutoff points of fasting insulin in Asian Indian adolescents may be helpful for detection of and application of primary prevention strategies for fasting hyperinsulinemia and the metabolic syndrome in this population.