Differences in the components of metabolic syndrome by age and sex: a cross-sectional and longitudinal analysis of a cohort of middle-aged and older Japanese adults

BACKGROUND: The prevalence of metabolic syndrome (MetS) in Japan, a super-aged society, is increasing and poses a major public health issue. Several studies have reported sex differences in the association between age and MetS prevalence. This study aimed to examine the association between age and the prevalence of MetS based on multiple screening criteria and MetS components by sex. METHODS: We used 6 years of individual-level longitudinal follow-up data (June 2012 to November 2018; checkup year: 2012–2017) of middle-aged and older adults aged 40–75 years in Japan (N = 161,735). The Joint Interim Statement criteria, International Diabetes Federation criteria, and another set of criteria excluding central obesity were used as the screening criteria for MetS. The prevalence of MetS and MetS components was cross-sectionally analyzed according to sex and age. A longitudinal association analysis of age, MetS, and MetS components by sex was performed using a multilevel logistic model, adjusted for lifestyle- and regional-related factors. RESULTS: Sex differences were observed in the prevalence and association of MetS and MetS components. In all age groups, the prevalence of central obesity was higher among women, and the prevalence of high blood pressure and fasting glucose was higher among men (P < 0.001). The prevalence of high triglyceride and low high-density lipoprotein cholesterol was higher among women aged > 60 years (P < 0.05). Based on the criteria of the Joint Interim Statement and International Diabetes Federation, the prevalence of MetS was higher among women than in men aged > 55 years (P < 0.001). Men had a higher prevalence of MetS without central obesity than women in all age groups (P < 0.001). The odds ratio for MetS and MetS components with aging was greater among women than in men. CONCLUSIONS: Medical management should be based on the prevalence of MetS and its components according to sex and age. In particular, the high prevalence of MetS without central obesity in middle-aged and older Japanese men suggests that the adoption of the Joint Interim Statement criteria, which do not precondition central obesity, should be considered. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-023-04145-0.