Background: The metabolic syndrome is a cluster of risk factors including hypertension, obesity, dyslipidemia, and impaired glucose metabolism, associated with cardiovascular disease. The metabolic syndrome also appears to predispose to cognitive dysfunction and dementia. In this study the association between the metabolic syndrome and cognitive function was examined in a population of the oldest old.
Methods: The Leiden 85-Plus Study is a population-based study of 599 persons from age 85 onward. Cognitive function was assessed annually from age 85 to 90 by means of four neuropsychological tests. The presence (n = 237) or absence (n = 325) of the metabolic syndrome was recorded at baseline. Cross-sectional and prospective associations between the metabolic syndrome and cognitive function were analyzed with linear mixed models, adjusted for sex and level of education.
Results: At age 85 the metabolic syndrome was not associated with lower cognitive performance. The metabolic syndrome was associated with a decelerated cognitive decline from age 85 to 90 on the Mini-Mental State Examination (additional annual effect 0.18 [0.07], p = 0.01), the Stroop Test (-1.49 [0.59], p = 0.01), and the Letter Digit Coding Test (0.26 [0.09], p = 0.005). This effect was mainly attributable to glucose, body mass index, and, to a lesser extent, blood pressure.
Conclusion: The association between the metabolic syndrome and accelerated cognitive decline, which has been reported in persons up to age 75, is not evident in a population of the oldest old. The concept of the metabolic syndrome may be less valid in this age group.