Effects of Changes in Metabolic Syndrome Status on Cognitive Function: A 10-Year Study in a Middle-Aged Population

The long-term cumulative impact of metabolic syndrome (MS) on cognitive decline remains uncertain. This study investigated how changes in MS status over 10 years relate to cognition and whether sex modifies this relationship. A total of 766 participants (mean baseline age: 54 years) from the Kaohsiung Atherosclerosis Longitudinal Study were enrolled. MS was defined using the modified National Cholesterol Education Program Adult Treatment Panel III criteria for Asian populations. Participants were categorized into four groups based on changes in MS status over the 10-year follow-up: never MS, ever MS, new MS, and persistent MS. Cognition was assessed using the Chinese version of the Montreal Cognitive Assessment (MoCA). Multivariate regression models were adjusted for age, sex, education, smoking status, physical activity, alcohol consumption, anxiety and depression. The results showed that participants with persistent MS had lower MoCA scores (β = -0.08, adjusted p = 0.020) compared to those who never had MS, with impairments primarily in the memory and language domains. This adverse effect was observed only in women (β = -0.12, adjusted p = 0.004), while no significant association was found in men (β = -0.03, adjusted p = 0.628). Individuals with nonpersistent MS (either ever or new MS) did not show significant cognitive decline compared to those who never had MS. This study demonstrates that persistent MS over a decade is linked to cognitive decline, with a more pronounced effect in women. These findings highlight the importance of early MS intervention in midlife, particularly for women, to reduce the risk of cognitive deterioration later in life.