Background: The aim of this study was to examine the prevalence of the metabolic syndrome (MetS) and its association with coronary heart disease (CHD) in Iranian older individuals.

Methods: In this cross-sectional study, the prevalence of the MetS was determined according to the Third Adult Treatment Panel (ATPIII), the World Health Organization (WHO) and the International Diabetes Federation (IDF) definitions in 720 men and women aged≥65 years. Logistic regression analysis was used to estimate the Odds Ratio (OR) of developing CHD in model 1 an age adjusted model, in model 2 adjusted for age, smoking status, premature history of CHD and LDL cholesterol and in model 3 adjusted for mentioned variables in model 2 plus the components of the MetS according to each definition.

Results: The prevalence of MetS was 50.8%, 41.9% and 41.8% by ATPIII, IDF and the WHO definitions, respectively. IDF had high agreement with the ATPIII definition. In model 2, the ATPIII and the WHO definitions of MetS were associated with CHD by the odds ratio of 1.6 (1.1-2.2) and 1.7 (1.9-2.4), respectively. In model 3, obesity (WHO definition) and high blood pressure (ATPIII and WHO definitions) were associated with CHD.

Conclusion: As defined by the ATPIII and WHO definitions, the MetS was associated with CHD even after adjustment for the conventional CHD risks, but after further adjustment for their components none of these definitions showed association with CHD.