Elevated serum total and LDL cholesterol in very old patients with Alzheimer's disease.

The relationships of serum lipids with Alzheimer's disease (AD) and other dementias in very old patients are not clear. All residents of an academic nursing home were studied clinically for dementia and for serum lipids. All those autopsied over a 7.7-year period had apolipoprotein E (apoE) genotyping and detailed neuropathological examination. Those with pathologically defined criteria for AD (n = 84) were compared to all others who also had clinical dementia but did not show AD changes (n = 22). In contrast to most other reports of serum lipids in very old patients with AD, total cholesterol (TC) and low density lipoprotein cholesterol levels were each significantly higher for those with AD. The lipid-AD associations were progressively stronger with increasing pathological certainty of AD diagnosis. These relationships remained significant after adjustment for apoE genotype and for other known risk factors. The lipid-AD associations in a very old cohort, and prior evidence that elevated TC in middle life is a risk factor for later dementia, prompt consideration of factors associated with lipid metabolism in the development of Alzheimer's dementia.