Male sex accelerates cognitive decline in GBA1 Parkinson's disease.

We evaluated 128 GBA and 432 nonGBA Parkinson's disease (PD) subjects available from Parkinson's Progression Markers Initiative. Baseline clinical features and dopaminergic activity were assessed, together with clinical follow-up (6.87 ± 3.2 years). Survival analyses assessed the independent and interactive effects of sex and GBA1 mutations on cognitive decline. At baseline, GBA-PD males showed severe motor impairment, sleep disorders and memory deficits. Despite milder motor deficit, compared to GBA-PD males, GBA-PD females showed greater dopaminergic denervation, suggesting the effect of neural reserve. In longitudinal assessment, GBA-PD males showed greater MoCA rate of change per year and greater risk of cognitive impairment than GBA-PD females and nonGBA-PD. In GBA-PD males, both late age at onset and "severe/mild" GBA variants were associated with increased risk of cognitive impairment. Male sex and GBA1 carrier status have an additive value in increasing the risk of cognitive decline in PD. The effect of sex on GBA1-related pathology warrants further examination to address future trials design and patients' selection.