Effect of Metabolic Syndrome on Parkinson’s Disease: A Systematic Review

Abstract

Evidence shows that metabolic syndrome (MS) is associated with a greater risk of developing Parkinson's disease (PD) because of the increase in oxidative stress levels along with other factors such as neuroinflammation and mitochondrial dysfunction. However, because some studies have reported that MS is associated with a lower risk of PD, the relationship between MS and PD should be investigated. This study aimed to investigate the effect of MS on PD. Two authors searched five electronic databases, namely, MEDLINE, PubMed, Scopus, PsycINFO, Web of Science, and Science Direct, for relevant articles between September and October 2020. After screening the title and abstract of all articles, 34 articles were selected for full-text review. Finally, 11 articles meeting the eligibility criteria were included in the study. The quality of articles was critically evaluated using the Joanna Briggs Institute. Overall, we evaluated data from 23,586,349 individuals (including healthy individuals, with MS and PD) aged 30 years or more. In cohort studies, the follow-up period varied between 2 and 30 years. MS contributed considerably to the increase in the incidence of PD. In addition, obesity, a component of MS, alone can increase the probability of developing neurodegenerative diseases. However, despite few studies on MS and PD, changes in cognitive function and more rapid progression of PD disease has been documented in patients with MS using methods commonly used in research.

Obsessive-Compulsive Disorder and Risk of Parkinson Disease: A Nationwide Longitudinal Study

“…Exact matching was performed to match this cohort in a 1:10 fashion to controls without diagnoses of neither PD and related diseases nor OCD before the enrollment on the bases of age (±1 year), sex, enrollment time, medical comorbidities, income level (levels 1-3 per month: ≤15,840 New Taiwan dollars [NTD] or 528 United States dollars [USD], 15,841-25,000 NTD or 528-833 USD, and ≥25,000 NTD or ≥833 USD), and urbanization level of residence (levels 1-5, most to least urbanized), a proxy for healthcare availability in Taiwan (15). Medical comorbidities included cerebrovascular diseases, traumatic brain injury, hypertension, dyslipidemia, and diabetes mellitus because those medical conditions may be related to PD risk (16,17). In addition, Charlson Comorbidity Index (CCI) and all-cause clinical visits were provided for the OCD and the matched-control cohorts.…”