Diabetes Mellitus is Associated with a Higher Relative Risk for Parkinson's Disease in Women than in Men.
BACKGROUND In general, the risk to develop Parkinson's disease (PD) is higher in men compared to women. Besides male sex and genetics, research suggests diabetes mellitus (DM) is a risk factor for PD as well. OBJECTIVE In this population-level study, we aimed at investigating the sex-specific impact of DM on new diagnoses of PD. METHODS Medical claims data were analyzed in a cross-sectional study in the Austrian population between 1997 and 2014. In the age group of 40-79 and 80+, 235,268 patients (46.6%females, 53.4%males) with DM were extracted and compared to 1,938,173 non-diabetic controls (51.9%females, 48.1%males) in terms of risk of developing PD. RESULTS Men with DM had a 1.46 times increased odds ratio (OR) to be diagnosed with PD compared to non-diabetic men (95%CI 1.38-1.54, p < 0.001). The association of DM with newly diagnosed PD was significantly greater in women (OR = 1.71, 95%CI 1.60-1.82, p < 0.001) resulting in a relative risk increase of 1.17 (95%CI 1.11-1.30) in the age group 40 to 79 years. In 80+-year-olds the relative risk increase is 1.09 (95%CI 1.01-1.18). CONCLUSION Although men are more prone to develop PD, women see a higher risk increase in PD than men amongst DM patients.