Differential patterns of effects of age and sex on metabolic syndrome in Taiwan: Implication for the inadequate internal consistency of the current criteria

Aims: Current criteria of metabolic syndrome (MetS) give equal weight to each component and apply mostly the same cut-off values to all ages. The contribution of each component to MetS and the effects of age and sex on each component and MetS were explored. Methods: We carried out a survey on residents aged 40-74 years of the northern coastal area of Taiwan. The prevalent rates of MetS in 646 males and 961 females were 32.4% and 27.8%, respectively. Logistic regression analyses were used to assess the main and interactive effects of age and sex. The Cronbach's α coefficient was calculated as the indicator of internal consistency of MetS components. Results: There were significant age trends for MetS components, except for low HDL-C in both sexes and high fasting triglyceride in males. Logistic regression analyses showed that the effects of age and sex on MetS and its component were all different. The age-sex-specific Cronbach's α coefficients for MetS ranged from 0.43 to 0.61. The age trends of the coefficients in males and females were opposite. The exclusion of some components from the MetS resulted in an increase of the coefficients. Conclusions: Our results indicate that the internal consistency of MetS was questionable. It seems that the currently defined MetS components of MetS did not formulate a single pathophysiological entity. Given equal weight to each component and used the same cut-off values for the subjects of all age groups in both sexes need to be reconsidered.