Objective: We investigated the relationship of metabolic syndrome (MetS) and its individual components with incident dementia in a prospective population-based study with a 3.5-year follow-up.
Methods: A total of 2,097 participants from a sample of 5,632 65-84 year old subjects from the Italian Longitudinal Study on Aging were evaluated. MetS was defined according to the Third Adults Treatment Panel of the National Cholesterol Education Program criteria. Dementia, Alzheimer’s disease (AD), and vascular dementia (VaD) were classified using current published criteria.
Results: MetS subjects (N°= 918) compared with those without MetS (N°= 1179) had increased risk for VaD (1.63% vs 0.85%, adjusted HR 3.71, 95% CI 1.40-9.83). After excluding 338 subjects with baseline undernutrition, MetS subjects compared with those without MetS had an elevated risk of VaD (adjusted HR, 3.82; 95% CI, 1.32-11.06). Moreover, those with MetS and high inflammation had a still further higher risk of VaD (multivariate adjusted HR, 9.55; 95% 1.17-78.17) compared with those without MetS and high inflammation. On the other hand, those with MetS and low inflammation compared with those without MetS and low inflammation did not exhibit a significant increased risk of VaD (adjusted HR, 3.31, 95% CI 0.91-12.14). Finally, a synergistic MetS effect vs its individual component effects was verified on the risk of VaD.
Conclusion: In our population, MetS subjects had an elevated risk of VaD, that increased after excluding patients with baseline undernutrition and selecting MetS subjects with high inflammation.