To summarize the evidence on the association between cholesterol and the risk of DBL

A systematic search was conducted in PubMed, Embase, Scopus, Web of Knowledge, and Google Scholar until September 2024. We included observational studies that evaluated the association between cholesterol levels (total cholesterol, HDL-C, and LDL-C) and DLB. Additionally, we analyzed the difference in cholesterol levels between DLB and Alzheimer’s disease (AD) patients. A meta-analysis using a random-effects model to estimate pooled effects was used for each outcome and a narrative synthesis when this was not possible. Healthy controls and other dementias were the comparators, and the outcome was the risk of DLB.  The Newcastle-Ottawa scale was used to assess the risk of bias.

We included 9 studies (92747 patients). Cholesterol levels were lower in patients with DLB compared with patients with AD. (MD: -0.50; 2 studies; 142 participants; 95% CI: -0.82 to -0.18; I2 = 0%; low CoE). In addition, LDL-C levels increase the risk of presenting Lewy bodies (OR: 1.40; 2 studies; 82981 participants; 95% CI: 1.21 to 1.61; I2 = 0%; high CoE) and, on the contrary, HDL-C levels decrease the risk of presenting Lewy bodies (OR: 0.83; 2 studies; 84781 participants; 95% CI: 0.75 to 0.91; I2 = 0%; high CoE). All studies had a low risk of bias.

There was an association between lower cholesterol levels and DLB compared with AD patients. In addition, LDL-C levels increase the risk of DLB, while HDL-C has a protective effect. However, further studies are necessary to confirm these findings.