Background: Although metabolic syndrome (METs) is receiving attention from physicians, data on the syndrome's association with coronary heart disease (CHD) in the Iranian population are limited. This study was designed to determine the association of different definitions of METs and its components with CHD.

Methods: Logistic regression analysis was used to analyze data from 5981 subjects aged ≥30 years. METs definitions by the International Diabetes Federation (IDF), the Adult Treatment Panel (ATP III) and the WHO for CHD were used in three models: model 1 an age adjusted model, model 2 adjusted for age, smoking status, premature history of CHD and LDL-cholesterol and model 3 adjusted for the mentioned variables plus the METs components.

Results: METs as delineated by all three definitions was associated with CHD in models 1 and 2. In model 2, METs was most closely associated with CHD in men, as defined by the WHO [2.3 (1.8-3)] and in women by the ATP III definition [1.6 (1.3-2)]. In model 3, METs lost its association with CHD. However, in men high fasting plasma glucose and high blood pressure plus obesity (by the WHO definition) and in women high blood pressure plus high waist circumference (by the ATP III definition), obesity and glucose domain (by the WHO definition) remained associated with CHD.

Conclusions: In Iranian men and women, all three definitions of METs were associated with CHD when considering the conventional risk factors. After further adjustments for the components of METs, none of these definitions showed an association with CHD and only high blood pressure correlated with CHD in both sexes for all definitions.