Role of lipoproteins and inflammation in cognitive decline: do they interact?

The aim of this study was to examine the associations between high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, triglycerides, and cognition and focus on the modifying effect of inflammation. Data were collected in the population-based Longitudinal Aging Study Amsterdam and analyzed with mixed linear models. The sample comprised 1003 persons ≥ 65 years with cognitive data on at least 2 occasions over 6 years of follow-up. Cognition was measured with the Mini-Mental State Examination (general cognition), Auditory Verbal Learning Test (memory), and Coding Task (information processing speed). We found an independent association between high HDL cholesterol and better memory performance. In addition, low LDL cholesterol was predictive of worse general cognitive performance and faster decline on information processing speed. Furthermore, a significant modifying effect of inflammation (C-reactive protein, α-antichymotrypsin) was found. A negative additive effect of low LDL cholesterol and high inflammation was found on general cognition and memory performance. Also, high triglycerides were associated with lower memory performance in those with high inflammation. Thus, a combination of these factors may be used as markers of prolonged lower cognitive functioning.