(HealthDay News) — Higher and lower levels of high-density lipoprotein cholesterol (HDL-C) are associated with an increased risk for Alzheimer’s disease and related dementia (ADRD), according to a study published online Oct. 4 in Neurology.
Erin L. Ferguson, MPH, from the University of California in San Francisco, and colleagues examined the observational associations of HDL-C and low-density lipoprotein cholesterol (LDL-C) with incident dementia in a cohort with linked survey and electronic health record data. Participants completed a health behavior survey between 2002 and 2007, had laboratory measurements of cholesterol within two years after survey completion, and were followed through December 2020 for incident dementia, including ADRD. Data were included for 184,367 participants.
The researchers found that the risk for ADRD was elevated in association with higher and lower HDL-C values compared with the middle quantile, with hazard ratios of 1.07 and 1.15 for HDL-C in the lowest and highest quintile, respectively. There was no association seen for LDL-C with dementia risk overall, but the association was qualitatively modified by statin use. Higher LDL-C was associated with an increased risk for ADRD for statin users (53% of the sample) and a lower risk for nonusers (hazard ratio per 10-mg/dL increase, 1.01 and 0.98, respectively). Evidence for effect modification was seen by age with linear HDL-C, but not LDL-C.
“The elevation in dementia risk with both high and low levels of HDL cholesterol was unexpected, but these increases are small, and their clinical significance is uncertain,” coauthor M. Maria Glymour, ScD, also from the University of California, San Francisco, said in a statement.