Factors correlated with excessive daytime sleepiness in patients with Parkinson's disease: A polysomnography study

OBJECTIVE: To explore the factors correlated with excessive daytime sleepiness (EDS) in patients with Parkinson's disease (PD). METHODS: A total of 239 PD patients were divided into two groups based on the presence of EDS (Epworth Sleepiness Scale score≥10) (PD‐EDS vs. PD‐non‐EDS). Participants underwent an extensive assessment to determine demographic features, disease severity, polysomnography characteristics, and nonmotor symptoms. RESULTS: Of the 239 patients, 56 patients (23.4%) were classified as having PD combined with EDS. Binary logistic regression analysis showed that fatigue (Fatigue Severity Scale [FSS] score ≥4) (odds ratio [OR] [95% CI] = 4.897 [2.376–10.095], p < .001) and the respiratory‐related microarousal index (OR [95% CI] = 2.063 [1.085–3.923], p = .027) were independent risk factors for EDS in PD patients. A priori‐determined stratified analysis showed that after adjustment for confounding factors, the association of the respiratory‐related microarousal index with EDS was significant (OR = 4.404, 95% CI 1.673–11.592, p trend = .036) in patients with respiratory arousal index scores in the highest quintile compared with those with scores in the lowest quintile. CONCLUSION: Our data revealed a close association among the respiratory‐related microarousal index, FSS scores, and EDS. It can be speculated that fragmented sleep and pathological abnormalities of the central nervous system resulting in changes in arousal are major influencing factors of EDS in PD.