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.