Relationship between low levels of high density lipprotein cholesterol and dementia in the elderly. The InCHIANTI stuDy

To evaluate the association between plasma lipid fractions and the prevalence of dementia in a large sample of Italian older individuals. METHODS: A total of 1051 older community-dwelling individuals (age >/=65 years), enrolled in the InChianti study, were included. Diagnosis of dementia was established at baseline and at the 3-year follow-up using Diagnostic and Statistical Manual of Mental Disorder (Fourth Edition) criteria. Plasma lipids were measured by standardized methods at baseline and after 3 years. RESULTS: At baseline, 61 individuals (5.8%) were affected by dementia. Demented individuals showed significantly lower total cholesterol (TC), nonhigh-density lipoprotein cholesterol, and high-density lipoprotein cholesterol (HDL-C) levels compared with controls; no differences were found in triglycerides (TG) and lipoprotein (a) levels. Of the 819 subjects reevaluated at the 3-year follow-up, 81 (9.9%) received a new diagnosis of dementia. Again, demented subjects were characterized by significantly lower TC, non-HDL-C, and HDL-C levels compared with controls, thus confirming the baseline findings. At multivariate logistic regression analysis, HDL-C levels (odds ratio: 0.96, 95% confidence interval: 0.93-0.99), but not TG and non-HDL-C, were associated with dementia independent of important confounders including age, gender, apo E phenotype, stroke, weight loss, interleukin 6 levels, and ankle-brachial index. CONCLUSIONS: Among community-dwelling older people, individuals affected by dementia showed significantly lower TC, non-HDL-C, and HDL-C levels; however, at multivariate analysis, only HDL-C was associated with dementia. Our results suggest the existence of an independent relationship between dementia and low HDL-C levels.