Reduced Plasma Desmosterol-to-Cholesterol Ratio and Longitudinal Cognitive Decline in Alzheimer's Disease

This cohort study measured the plasma desmosterol-to-cholesterol ratio (DES/CHO) in 401 participants across Alzheimer’s disease and control groups, and examined whether DES/CHO correlated with cognitive decline over longitudinal follow-up.

Plasma DES/CHO was significantly reduced in Alzheimer’s disease patients compared with controls, and lower DES/CHO correlated with worse MMSE scores and greater cognitive decline in patients who progressed most rapidly. Desmosterol is a cholesterol synthesis intermediate that decreases when cholesterol synthesis is downregulated — its reduction may reflect impaired neuronal cholesterol metabolism in AD.

This article lies at the boundary of the cardiovascular research base. While cholesterol metabolism is relevant to both CAD and Alzheimer’s disease, the specific question here — desmosterol as an AD progression biomarker — is not directly related to subclinical coronary artery disease, diagnosis, or treatment. The indirect relevance is that cholesterol-lowering therapy (particularly statins) may affect desmosterol levels and potentially neurological outcomes, though this remains unresolved and epidemiologically controversial.

We rate the evidence moderate for its stated purpose. A well-analyzed cohort study identifying plasma DES/CHO as a potential AD progression marker — of interest for the cholesterol-neurodegeneration interface but tangential to core CAD research.