Factor analysis of metabolic syndrome among the middle-aged Bengalee Hindu men of Calcutta, India

Background: The prevalence of coronary heart disease (CHD) is known to be very high in the people of Indian origin. In India, rates are rising and CHD has been predicted to rank first among the causes of death in the Indian population by 2015. The reasons for the increased susceptibility of Indians to CHD are yet to be understood completely. However, studies hinted that clustering of risk variables of the metabolic syndrome (MS) could be responsible for the increasing incidence of CHD in the Indians. Therefore, identification of the components of the MS could be one aspect in the way to curb the increasing incidence of CHD among the Asian Indians.

Methods: Principal component factor analysis (PCFA) was undertaken to identify the components or factors of the metabolic syndrome (MS) among the middle-aged Bengalee Hindu men of Calcutta, India, and was compared with the findings from other studies. The present cross-sectional study consisted of 212 Bengalee Hindu men aged 30 years and above. Besides anthropometric measures, lipid profile, blood pressure, and fasting plasma glucose (FPG) were collected from each participant. Waist-hip ratio (WHR), trunk-extremity ratio (TER), and central fat skinfold ratio (CFSR) were computed accordingly. The lipid profile measures that were included were total cholesterol (TC), fasting triglyceride (FTG), high (HDL-C), low (LDL-C), and very low density lipoprotein cholesterol (VLDL-C).

Results: Principal components factor analysis revealed four uncorrelated factors that cumulatively explained 72.37% of the observed variance of the metabolic syndrome by measured variables. These four factors could be identified as central obesity (factor 1), centralized subcutaneous fat (factor 2), lipid profile blood glucose (factor 3), and blood pressure (factor 4). The present factor analysis confirms the general finding from other factor analyses of the metabolic syndrome on different ethnic groups that have identified three to four factors. Furthermore, the first two factors, that is, central obesity and centralized subcutaneous fat cumulatively explained 47% of the observed variance of metabolic syndrome in this population.

Conclusion: Since more than one factor was identified for the metabolic syndrome and as no observed variable loaded on all four factors, therefore, more than one physiological mechanism could be accounted for the clustering of risk variables of the metabolic syndrome among the Bengalee Hindu men.