Characterizing sleep-related phenotypes with patient-reported outcomes in Parkinson's disease.

Objective: Sleep disturbances are common in Parkinson's disease (PD) and significantly impact patients' quality of life. However, the clinical symptoms associated with poor sleep remain underexplored. The Patient-Reported Outcomes in PD (PRO-PD) is a remote patient monitoring tool enabling symptom-level resolution. The goal of this study was to use the PRO-PD to describe symptomatic differences associated with sleep quality. Methods: A cross-sectional analysis was conducted using baseline data of an ongoing prospective cohort study of patients with idiopathic PD (IPD). Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), while disease severity was evaluated using the PRO-PD. Multivariable regression analysis was performed to judge the association between PSQI and PRO-PD, adjusting for age, gender, income, and years since diagnosis. Results: Among 331 participants, 70.2% of patients with IPD reported poor sleep quality (PSQI>5). Furthermore, a significant positive correlation was observed between PSQI scores and PRO-PD scores (p = 2.24 × 10-12). Multivariable regression analysis confirmed this association, with each unit increase in the PSQI score corresponding to a 39.7-unit increase in the PRO-PD score (p = 1.25 × 10-8). Sleep quality was most strongly correlated with self-reported insomnia (ρ = 0.69), with moderate associations observed for fatigue, anxiety, poor balance, depression, and apathy (ρ = 0.29-0.37), and weaker associations with myalgia, visual complaints, cognition, restless legs, gait, posture, and urinary symptoms (ρ = 0.20-0.28). Conclusion: Poor sleepers showed uniformly higher PRO-PD burden, with a non-motor phenotype consisting of insomnia, fatigue, anxiety, and depression consistent with prior reports. The PRO-PD further identified additional equally-correlated symptoms, such as poor balance, lacking motivation, and social withdrawal providing expanded perspective. These findings highlight the need for routine sleep assessments in PD management and suggest that interventions targeting sleep disturbances may alleviate symptom burden and improve QoL. Future longitudinal studies could help establish causality and explore therapeutic strategies to improve sleep quality in PD.