Clinical differences between early-onset and mid-and-late-onset Parkinson's disease: Data analysis of the Hellenic Biobank of Parkinson's disease.

BACKGROUND: Age at onset is one of the most critical factors contributing to the clinical heterogeneity of Parkinson's disease (PD), and available evidence is rather conflicting. OBJECTIVE: The aim of this study is to investigate the clinical differences between early-onset PD (EOPD) and mid-and-late-onset PD (MLOPD) in the Greek population, based on the existing data of the Hellenic Biobank of PD (HBPD). METHODS: HBPD contains information of PD cases from two centers in Greece during 2006-2017. Patients with the A53T mutation in the SNCA gene or mutations in the GBA1 gene were excluded. Associations between clinical characteristics (motor and non-motor symptoms, side of onset, first symptom, motor complications) and MLOPD versus EOPD were explored with a single logistic regression model adjusting for gender, family history of PD, disease and dopaminergic therapy duration, disease severity (UPDRS III), levodopa equivalent daily dose, as well as each of the other clinical characteristics. RESULTS: 675 patients (129 EOPD, 546 MLOPD) were included. EOPD was more frequently associated with dystonia (OR 0.19, 95% CI 0.08-0.50, p < 0.01) and motor complications (0.23, 0.07-0.76, 0.02), compared to MLOPD. Bilateral onset (9.38, 1.05-84.04, 0.045) and autonomic dysfunction (2.31, 1.04-5.11, 0.04) were more frequently associated with MLOPD. CONCLUSIONS: EOPD and MLOPD display distinct clinical profiles, regarding motor and non-motor symptoms, side of onset and motor complications in the Greek population. These differences may reflect diverse pathophysiological backgrounds, potentially attributed to genetic or age-related epigenetic influences.

The relationship between environmental factors and different Parkinson's disease subtypes in Greece: Data analysis of the Hellenic Biobank of Parkinson's disease.

INTRODUCTION: The aim of this study is to investigate the association between environmental factors (smoking, coffee, pesticide exposure) and Parkinson's disease (PD) subtypes (early-onset, mid-and-late onset, familial and sporadic) in the Greek population. METHODS: The Hellenic Biobank of PD recorded information of PD cases and controls from two centers in Greece during 2006-2017. Patients with the A53T mutation in SNCA or GBA mutations were excluded. Associations of environmental factors with PD overall (and PD subtypes) versus controls were explored with logistic regression models adjusting for age, gender and each environmental factor. RESULTS: 686 patients and 356 controls were included. Smoking was associated with a reduced risk of PD overall (OR 0.48, 95% CI 0.35-0.67), mid-and-late onset (0.46, 0.32-0.66), familial (0.53, 0.34-0.83) and sporadic (0.46, 0.32-0.65), but not early-onset PD. There was an inverse linear association with pack-years of smoking, except for early-onset PD. Early-onset PD was the only PD subtype inversely associated with coffee consumption when dichotomously treated. Compared to never-coffee drinkers, only those at the upper tertile had lower odds for PD overall (0.52, 0.29-0.91), early-onset (0.16, 0.05-0.53) and familial PD (0.36, 0.17-0.75). No associations were found between pesticides and PD. CONCLUSIONS: Our study shows that the well-known negative association of smoking with PD occurs across all PD subtypes in the Greek population, apart from early-onset PD. Early-onset PD was also most strongly inversely associated with coffee consumption, highlighting a potential distinct underlying physiopathology in this PD subset that may involve specific gene-environment interactions.