Men experiencing symptoms of sleepwalking and/or REM sleep behavior disorder may be at greater risk of having Parkinson disease (PD), according to study findings published this week in JAMA Network Open.
As one of the most common nonmotor symptoms in PD, sleep-related symptoms affect more than 75% of people with the condition. Among these symptoms, researchers highlight that REM sleep behavior disorder (RBD) and sleepwalking, which is caused by non-REM sleep, both have high prevalence in PD.
“Given that sleepwalking is generally considered a rare condition in adults [1.0%-2.3%], this prevalence in patients with PD [approximately 10%] appears unusually high, but to our knowledge, no study to date has included a group of individuals without PD in direct comparison for risk estimation,” said the study authors.
Researchers conducted a cross-sectional study of data from the Health Professionals Follow-Up Study (N = 25,694; mean [SD] age, 75.6 [7.4] years), a population-based cohort of male health professionals, to assess the association between probable sleepwalking and probable RBD with PD.
Data were derived between January 2012 and June 2018, with data analysis performed from July 2020 to October 2020. Of the study cohort, 223 (0.9%) participants were found to have probable sleepwalking, 2720 (10.6%) had probable RBD, and 257 (1.0%) had documented cases of PD.
Compared with those without sleep parasomnias, participants with probable sleepwalking or probable RBD were more likely to have longer sleep duration (2407 [12.7%] vs 18 [17.1%] or 462 [17.8%]), prevalent daytime sleepiness (2291 [12.1%] vs 20 [19.1%] or 466 [18.0%]), hypnotics use (3224 [17.0%] vs 42 [39.3%] or 497 [19.3%]), and restless leg syndrome (961 [5.7%] vs 9 [9.7%] or 134 [6.3%]).
After adjusting for potential confounders, including age, smoking, caffeine intake, chronic disease status, and other sleep disorders, probable sleep walking and probable RBD were significantly associated with PD:
- PD risk in people with probable sleepwalking (adjusted odds ratio [OR], 4.80; 95% CI, 1.61-14.26)
- PD risk in people with probable RBD (adjusted OR, 6.36; 95% CI, 4.83-8.37)
- PD risk in people with both probable sleepwalking and probable RBD (adjusted OR, 8.44; 95% CI, 3.90-18.27)
Researchers note that the multiplicative interaction between probable sleepwalking and probable RBD was not significant. “Similar results were observed after excluding participants with restless leg syndrome. No significant interaction was found with age, smoking status, or caffeine consumption,” said the study authors.
When stratifying for PD duration, researchers found that probable sleepwalking without probable RBD was only significantly associated with PD among those with disease duration of 4.1 years to 8 years (OR, 6.27; 95% CI, 1.32-29.81) and more than 8 years (OR, 12.05; 95% CI, 3.22-45.04).
Conversely, probable RBD without probable sleepwalking was consistently associated with higher odds of PD across disease duration groups (4 years: OR, 6.47; 95% CI, 4.33-9.60; 4.1-8 years: OR, 5.35; 95% CI, 3.33-8.57; > 8 years: OR, 7.11; 95% CI, 4.43-11.41).
“Prospective cohort studies in which long-term follow-up data are available with a reasonable number of sleepwalking and PD cases are warranted for better understanding the association,” concluded the study authors.
Zhang X, Molsberry SA, Pavlova M, et al. Association of sleepwalking and REM sleep behavior disorder with Parkinson disease in men. JAMA Netw Open. Published online April 13, 2021. doi:10.1001/jamanetworkopen.2021.5713