Socioeconomic Status and Lifestyle Factors Differences in the Association Between Dietary Patterns and Metabolic Syndrome: Tehran Lipid and Glucose Study.

Socioeconomic status and lifestyle factors could potentially modify the association between diet and chronic diseases such as metabolic syndrome (MetS). This study aimed to investigate the combined effect of socioeconomic status, lifestyle factors, and dietary patterns on the MetS risk. During 8.9 years of follow-up, dietary information of 1915 individuals was collected by a validated Food Frequency Questionnaire (FFQ). Dietary patterns were derived using principal component analysis. Two major dietary patterns including healthy dietary and Western dietary patterns were identified. In the crude and fully adjusted models, an association was not found between Western and healthy dietary patterns and the risk of MetS. There was a significant decrease in the risk of MetS among participants with higher levels of education who adhered to a healthy dietary pattern (hazard ratio: 0.71, 95% confidence interval: 0.34-0.89). Furthermore, the risk of MetS decreased in the fourth quartile of healthy dietary pattern among nonemployed (0.78, 0.51-0.94). According to the stratification of physical activity levels, it was shown that the healthy dietary pattern had a negative association with the risk of MetS only among participants who engaged in a high level of physical activity (0.70, 0.40-0.91). About the smoking status, it was shown that among non-smoker participants, higher adherence to a healthy dietary pattern was associated with a reduction in the risk of MetS. The risk of MetS reduced by 36% (0.64, 0.51-0.97) in the third quartile and by 39% (0.61, 0.54-0.95) in the fourth quartile of the healthy dietary pattern. No association was found between Western dietary pattern with MetS in different status of socioeconomic and lifestyle factors. Adhering to a healthy dietary pattern, engaging in regular physical activity, and abstaining from smoking could reduce incidents of MetS. Moreover, socioeconomic status modified the association between healthy dietary pattern and MetS.