Risky Behaviors and Parkinson's Disease

TAKE-HOME MESSAGE

Parkinson’s disease (PD) is a complex neurodegenerative disease, likely caused by a combination of genetic and environmental factors. Epidemiologic data suggest an interaction between risk-taking behavior and the risk of PD. This study uses a Mendelian randomization methodology, which allows the examination of causal effects of multiple exposures in the same disease, applied to data from two large meta-analyses of genome-wide association studies. There was a general trend toward association of risk tolerance with PD. The strongest protective association was between a tendency to smoke and PD, with an odds ratio of 0.714 per log odds of ever smoking. Interestingly, no association was seen for number of cigarettes per day, cannabis dependence, pathologic gambling, or alcohol and coffee consumption. Associations for other risky behaviors, such as number of sexual partners and automobile speed, were less robust.

The results support the causal relationship between genetic factors and PD in relation to risky behaviors, in particular genetic associations for smoking and PD. These associations are quite complex, worthy of further investigation, and can also offer a window into pathogenic mechanisms.