Risk of Parkinson Disease Onset in Patients With Diabetes: A 9-year population-based cohort study with age and sex stratifications

OBJECTIVE: We retrospectively assessed the age- and sex-specific incidence and relative risk of Parkinson disease (PD) in Taiwan’s diabetic population. RESEARCH DESIGN AND METHODS: Study cohort included 603,416 diabetic patients and 472,188 nondiabetic control subjects. Incidence rate and relative risk of PD (ICD-9-CM 332.0) were evaluated. RESULTS: The incidence of PD was 3.59 and 2.15 per 10,000 person-years for the diabetic and control group, respectively, representing a covariate adjusted hazard ratio (HR) of 1.61 (95% CI 1.56–1.66), which was substantially reduced to 1.37 (1.32–1.41) after adjusting for medical visits. Diabetes was associated with a significantly elevated risk of PD in all sex and age stratifications except in young women, with the highest HR noted for young men aged 21–40 years (2.10 [1.01–4.42]), followed by women aged 41–60 (2.05 [1.82–2.30]) and >60 years (1.65 [1.58–1.73]). CONCLUSIONS: Diabetes is associated with an increased risk of PD onset in a Chinese population, and the relation is stronger in women and younger patients.