The metabolic syndrome (MS) in the elderly: considerations on the diagnostic criteria of the International Diabetes Federation (IDF) and some proposed modifications.

This study aimed at verifying the International Diabetes Federation (IDF)-indicated criteria in the elderly, characterized by a decrease of several normal values, the neglected evaluation of those values with aging, and an eventual decision of an obligatory consideration of the visceral obesity as a sign of the metabolic syndrome (MS), the relative prevalence of Acute Myocardial Infarction (AMI) and stroke. The study involved 3038 elderly persons (65-84 years), covered by the Italian Longitudinal Study on Aging (ILSA): they were investigated for the diagnosis of MS, for the prevalence of AMI and stroke at the baseline, and after 3 years. We applied both the IDF-criteria and a new concept considering the age-dependent increase of several parameters in older subjects, the previous cardio-cerebrovascular complications, as well as the presence of other diseases being independent of those complications. The prevalence of AMI and stroke determined according to the IDF-criteria is not different significantly from the results obtained in either the elderly population with "normal" or increased waist circumference (WC), nor in subjects with MS or without MS. After a 3-year-follow-up quite similar results were found. From these results one can conclude that the diagnostic criteria of the IDF for the MS are not valid for the elderly population. We propose some criteria on the basis of which one can reveal systematically significant differences between the MS and the cardiovascular complications. Our conclusion is that it seems to be necessary to verify the validity of our proposed criteria on wider long-term epidemiological studies.