Metabolic Syndrome and 16-Year Cognitive Decline in Community-Dwelling Older Adults

PURPOSE: To determine whether metabolic syndrome is associated with accelerated cognitive decline in community-dwelling older adults. METHODS: A longitudinal study of 993 adults (mean 66.8 +/- 8.7 years) from the Rancho Bernardo Study. Metabolic syndrome components, defined by 2001 NCEP-ATP III criteria, were measured in 1984-1987. Cognitive function was first assessed in 1988-1992. Cognitive assessments were repeated approximately every 4 years, for a maximum 16-year follow-up. Mixed-effects models examined longitudinal rate of cognitive decline by metabolic syndrome status, controlling for factors plausibly associated with cognitive function (diabetes, inflammation). RESULTS: Metabolic syndrome was more common in men than women (14% vs. 9%, p = .01). In women, metabolic syndrome was associated with greater executive function and long-term memory decline. These associations did not differ by inflammatory biomarker levels. Diabetes did not alter the association of metabolic syndrome with long-term recall but modified the association with executive function: metabolic syndrome was associated with accelerated executive function decline in diabetic women only. Metabolic syndrome was not related to rate of decline on any cognitive measure in men. CONCLUSIONS: Metabolic syndrome was a risk factor for accelerated cognitive decline, but only in women. Prevention of metabolic syndrome may aid in maintenance of cognitive function with age. Ann Epidemiol 2012;22:310-317. (C) 2012 Elsevier Inc. All rights reserved.