Sexual dysfunction in male patients with Parkinson's disease: related factors and impact on quality of life.

BACKGROUND: Sexual dysfunction (SD) is a common, yet under-reported, non-motor symptom (NMS) of Parkinson's disease (PD). The present study investigated the sexual functions in PD male patients, its correlation with motor and other NMSs, and their impact on health-related quality of life (HRQoL). METHODS: The sexual functions of 40 PD male patients were assessed using the International Index of Erectile Function (IIEF) and compared to 25 healthy age-matched controls. Patients were evaluated using the NMS Scale (NMSS) and the Arabic version of the Parkinson's-Disease Questionnaire (PDQ-39). We compared the sexual functions of younger (≤ 55 years) and elder (> 55 years) males and tested the correlations between sexual functions and motor, other NMSs, and HRQoL. RESULTS: Seventy percent of PD male patients reported erectile dysfunction. They showed significantly worse total (p < 0.001) and subscores of IIEF, compared to healthy controls. The total IIEF was inversely correlated to age of patients (p = 0.013), age at onset (p = 0.043), total, cognitive/mood, gastrointestinal and urinary domains of NMSS, and the cognitive domain of PDQ-39 (p = 0.013). Age was the main predictor (ß = - 0.581, p = 0.006) of SD. Elder patients showed worse sexual functions, stronger correlations to other NMSs, and more impact on HRQoL than younger patients. CONCLUSION: Sexual functions are worse among PD male patients with age as the main predictor. SD was associated with worse cognitive/mood and urinary domains of NMSS and has a negative impact on the patients' HRQoL among elder males.