Total serum cholesterol levels and Alzheimer's dementia in patients with Down syndrome.

Background: The risk for dementia in Alzheimer's disease (DAD) in adults with Down syndrome (DS) is higher than in the general adult population. Hypercholesterolaemia has been reported as a risk factor for DAD in the general population. This study investigated the role of serum cholesterol levels in the onset of DAD in the DS population.

Methods: This study investigated total serum cholesterol levels in 179 DS persons (with and without DAD). The possible association between Apolipoprotein E and amyloid beta1-40 and beta1-42 levels was also investigated.

Results: No statistically significant association was found between total serum cholesterol levels and dementia in AD or with amyloid beta levels. However for DS adults with an apoE epsilon4 allele significantly higher serum cholesterol levels were found.

Conclusion: Hypercholesterolaemia is not a risk factor for DAD in persons with DS. However, DS persons with an apoE epsilon4 allele are susceptible to high serum cholesterol. Such individuals should be screened on a regular basis.