ABSTRACT
The aim of the present study was to assess the diagnostic accuracy of the modified ATP III and IDF definitions of the metabolic syndrome in identifying of insulin resistant individuals by HOMA-IR and to assess levels of agreement between these definitions and insulin resistance. The sample consisted of 347 nondiabetic subjects from the TLGS population [140 men and 207 women aged 27-87 years]. The reference standard for insulin resistance was determined by HOMA-IR and insulin resistance was defined as HOMA-IR >/= 2.5. According to ATP III and IDF criteria 38.9%, 45% had metabolic syndrome respectively. The sensitivity and specificity of ATP III was 52.3% and 65% respectively, and this was 60% and 59% for IDF criteria respectively. Kappa agreement between modified ATP III and IDF with HOMA-IR was 0.14 and 0.15. Based on the area under the receiver operating characteristic curve constructed by counting metabolic syndrome components as recommended by modified ATP III and IDF diagnostic accuracy was fair. When each component of metabolic syndrome measures were considered as continuous traits, waist circumference and fasting plasma glucose each separately had diagnostic accuracy equal or grater than at all the metabolic syndrome as a whole by ATP III and IDF criteria. ATP III and IDF definition have low sensitivities for detecting insulin resistance and there is poor agreement between those criteria and insulin resistance. Measuring just waist circumference and fasting plasma glucose is simpler and may provide greater accuracy for identifying insulin resistance