Antibiotic Exposure and Risk of Parkinson Disease in South Korea: A Nationally Representative Retrospective Cohort Study.

Background and objectives: Recent studies have suggested that antibiotics could be a contributing factor to Parkinson disease (PD), but validation in other population cohorts, such as Asians, is needed. This study examined the association between exposure to antibiotics and PD risk in the Korean population.

Methods: Using the National Health Insurance Service (NHIS) database, this population-level cohort research study from Korea included 298,379 people aged 40 years and older who underwent a national health examination in 2004-2005. Cumulative antibiotic exposure days were investigated over 4 years (2002-2005), and new cases of PD were followed for 14 years (2006-2019). Various covariates, such as infectious diseases, were considered in the analysis. Multivariable Cox proportional hazards regression was used to calculate adjusted hazard ratios (aHRs) and CIs for the PD risk from antibiotic exposure.

Results: PD risk was statistically significantly higher in those exposed to antibiotics for ≥121 days than in those not exposed to antibiotics (aHR, 1.29; 95% CI 1.07-1.55). In addition, compared with those exposed to antibiotics for 1-14 days, those exposed to antibiotics for ≥121 days had a higher risk of PD (aHR, 1.37; 95% CI 1.17-1.61). The results of sensitivity analyses that applied washout periods or extended antibiotic exposure periods were consistent with those of the main analyses.

Discussion: Extended usage of antibiotics was linked to a higher incidence of PD, even after controlling for several risk variables. Further research is needed to warrant the causation and mechanisms of antibiotic exposure and PD.