An unexpected higher prevalence of Parkinson's disease in females than males in the province of Trento (Italy): A clues for the etiopathogenesis?

Objectives: Parkinson’s disease (PD) is a sporadic neurodegenerative disorder that affects mainly older individuals. The worldwide estimate of the prevalence rate of PD is 31.5 cases per 10,000 pop (95% CI 11.3-87.3). The aim of the present study is to estimate for the first time the prevalence of PD along with its relation to age, gender, and geographical location in the population of Trentino using a novel methodology. Methods: We identified all potential PD cases using five sources. The originality of our methodological approach is the use of the provincial health information system (PIS), that allowed us to screen singularly the clinical reports of each possible patient with PD. Pre-existing diagnoses of PD were not accepted as reported, but Gelb’s criteria were applied to confirm each diagnosis. Results: Overall crude prevalence of PD was 21.43 per 10.000 pop, while crude prevalence rates of PD in males and females were respectively 20.64 and 22.19 per 10.000 pop. These prevalence rates are very similar to those reported by high quality studies such as door to door studies. Conclusions: Our study used a novel methodological approach to estimate the prevalence of PD in Trentino. Our results confirm that the prevalence of PD increases with age. However, we found an unexpected higher prevalence of PD in females, with anM/F ratio lower than one. Our findings open new perspectives in the complex pathogenic mechanisms of PD, including possible interactions between genetic and environmental factors.