Effects of Higher Serum Lipid Levels on the Risk of Parkinson's Disease: A Systematic Review and Meta-Analysis

Abstract

Background: The causal relationship between serum lipid levels and the risk of Parkinson's disease (PD) remains largely uncertain. We summarized the existing controversial evidence on this topic. Methods: We searched the electronic databases for observational studies from January 1988 to March 2020. We applied random-effects models to calculate pooled relative risk (RR) with their 95% confidence intervals (CI). Random-effects dose-response meta-analyses were further conducted to explore the dose-risk relationship. Results: Twelve cohort studies and three case-control studies were included in this meta-analysis. Higher levels of serum low-density lipoprotein cholesterol (LDL-C) were inversely associated with the subsequent risk of PD (RR 0.73, 95% CI 0.57–0.93), whereas, there were no associations between serum levels of total cholesterol (TC) (RR 0.91, 95% CI 0.73–1.13), high-density lipoprotein cholesterol (HDL-C) (RR 0.97, 95% CI 0.73–1.27), or triglycerides (TG) (RR 0.85, 95% CI 0.55–1.29) and the risk of PD. Further dose-response meta-analysis revealed that every 38.6 mg/dL (1mmol/L) increase in serum LDL-C correlates with a 7% decreased risk of PD. Conclusions: Our paper supports the protective effect of higher serum LDL-C on the subsequent risk of PD. More prospective cohort studies are warranted to confirm the conclusion, and further fundamental researches are needed to elucidate the underlying biological mechanisms.

Dysregulation of Neuronal Nicotinic Acetylcholine Receptor–Cholesterol Crosstalk in Autism Spectrum Disorder

“…The complex constellation of metabolic mechanisms discussed in the preceding section is subject to dysregulation, as is observed in various chronic neurodegenerative disorders (Shobab et al, 2005;Bi and Liao, 2010;Vancampfort et al, 2013;Leoni and Caccia, 2015;Jiang et al, 2020). In addition, there are various ASD-associated syndromes that also present alterations in cholesterol homeostasis.…”

Insights on Genetic and Environmental Factors in Parkinson’s Disease from a Regional Swedish Case-Control Cohort

“…However, this was only observed in case-control studies, indicating that the association might be a consequence of the disease. For hyperlipidemia, there are conflicting reports on the association with PD, but a meta-analysis supports an inverse association [ 61 ]. It is possible that the use of lipid-lowering drugs (statins) contributes to the observed conflicting associations [ 62 ].…”

Insights on Genetic and Environmental Factors in Parkinson’s Disease from a regional Swedish Case-Control Cohort

“…For hyperlipidemia, there are conflicting reports on the association with PD. However, a meta-analysis supports an inverse association between hyperlipidemia, specifically serum low-density lipoprotein cholesterol, and PD (66). It is possible that the use of lipid-lowering drugs (statins) contributes to the observed conflicting associations (67).…”

“…However, this was only observed in case-control studies, indicating that the association might be a consequence of the disease. For hyperlipidemia, there are conflicting reports on the association with PD but a meta-analysis supports an inverse association [62]. It is possible that the use of lipid-lowering drugs (statins) contributes to the observed conflicting associations [63].…”