National Cholesterol Educational Program and International Diabetes Federation diagnostic criteria for metabolic syndrome in an Italian cohort: Results from the FIBAR Study

Background: The adoption of the International Diabetes Federation (IDF) criteria for metabolic syndrome (MS), in comparison with the National Cholesterol Educational Program (NCEP) criteria, produces different changes in estimates of prevalence in diverse populations. Few data are available in Caucasian non-diabetic subjects. Patients and methods: The prevalence of NCEP- and IDF-defined MS was assessed in a sample of 2,945 individuals, aged 55.2±11.5 yr, enrolled in a screening program for diabetes. Association of different definitions of MS with glucose intolerance (120-min glucose 7.8 mmol/l after a 75 g-oral glucose load) and hyperuricemia (>0.38 mmol/l) was also assessed. Results: The prevalence of MS was 16.6% and 29.7% with NCEP and IDF definitions, respectively. The prevalence of NCEP-defined MS was higher than IDF-MS through all age ranges; among those aged >60 yr, the prevalence of IDF-MS reached 52.8% (vs 33.1% for NCEP-MS). Both NCEP- and IDF-MS were associated with glucose intolerance and hyperuricemia. Individuals fulfilling IDF, but not NCEP criteria for MS, showed a prevalence of glucose intolerance (22.7%) significantly (p<0.05) lower than those fulfilling NCEP criteria only (31.6%) or both sets of criteria (31.8%). Conclusion: In Caucasian subjects without known diabetes, IDF criteria produce a relevant increase in estimates of prevalence of MS, particularly in older subjects, when compared with NCEP criteria. NCEP-MS seems to be more effective than IDF-MS in the identification of glucose intolerant subjects.