Erectile dysfunction (ED) is associated with a higher risk of developing Parkinson’s disease, according to a new study.
In a population-based retrospective cohort study using data from the Taiwan National Health Insurance (NHI) program, researchers led by Tengfu Hsieh, MD, Taichung Tzu Chi Hospital in Taiwan compared 3153 men newly diagnosed with ED with 12,612 randomly selected men without ED (controls). The incidence rate of Parkinson’s disease was significantly higher in ED group than controls (3.44 vs 1.64 per 1000 person-years), the investigators reported in the Journal of Clinical Neurology (2017;13:250-258). The ED patients had a 52% higher risk of Parkinson’s disease, after adjusting for age and comorbidities. Compared with controls, ED patients with diabetes or hypertension had a 2.8 times and 2.2 times higher risk of Parkinson’s disease, respectively.
The researchers also matched men with organic ED by propensity score to men in the control group and found that the men with organic ED had a 43% higher risk of Parkinson’s disease.
The mean ages of the ED and control groups were 56.7 and 53.4 years, respectively. Investigators followed up patients from their index date (when ED was diagnosed) to the date of Parkinson’s disease diagnosis, withdrawal from the NHI program, or the end of 2012, whichever occurred first. The mean follow-up times for the ED and control groups were 5.0 and 6.8 years, respectively.
With respect to possible mechanisms to explain a link between ED and Parkinson’s disease, Dr Hsieh’s team noted that ED is among the manifestations of parasympathetic cholinergic failure, and the findings of previous studies suggest that many non-motor symptoms and autonomic dysfunction could early signs of preclinical stages of Parkinson’s disease. Testosterone levels also might have a role. Lower testosterone levels, they noted, are an important component of ED, and previous studies have shown that testosterone deficiency is frequently found in men with Parkinson’s disease compared with age-matched controls.
The new study adds to growing evidence of a link between ED and future development of Parkinson’s disease. In a paper published in the American Journal of Epidemiology (2007;166:1446-1450), researchers reported on a study demonstrating an association between ED and later development of Parkinson’s disease. The study included 32,616 men who participated in the Health Professionals Follow-up Study who were free of Parkinson’s disease at baseline in 1986 and, in 2000, completed a retrospective questionnaire with questions on ED in different time periods. Among men who reported having erectile function prior to 1986, 200 were diagnosed with Parkinson’s disease during the period from 1986 to 2002. Men with ED before 1986 were 3.8 times more likely to develop Parkinson’s disease during follow-up than men with very good erectile function. In multivariable analysis, men with first onset of ED prior to 1986 when they were aged 60 years or more, 50–59 years, and younger than 50 years had a 2.7, 3.7, and 4.0 times higher risk of Parkinson’s disease relative to men without ED.
Yang Y, Liu H, Lin T, et al. Relationship between erectile dysfunction, comorbidity, and Parkinson’s disease: Evidence from a population-based longitudinal study. J Clin Neurol 2017;13:250-258).
Gao X, Chen H, Schwarzschild MA, et al. Erectile function and risk of Parkinson’s disease. Am J Epidemiol 2007;166:1446-1450.