Patients With Sleep Apnea, Restless Leg Syndrome Exhibit Higher Insomnia-Specific Psychological Symptoms

Compared with patients who have just sleep apnea syndrome (SAS), those with both SAS and restless leg syndrome (RLS) were shown to exhibit a higher degree of insomnia-specific psychological symptoms, which may indicate the benefit of cognitive behavioral therapy in these populations, according to study findings published in Sleep and Breathing.

As the researchers highlight, SAS and RLS are both associated with disturbed sleep. Although SAS serves as a common comorbidity of RLS (SAS-RLS), data on the impact of both sleep disorders in insomnia-specific symptoms are rare. Patients with SAS-RLS have been shown to experience impaired daytime performance and sleep-related worries.

“The fact that SAS-RLS shows more insomnia-specific psychological symptoms may give further information regarding the etiology of insomnia as well as the need for possible additional treatment options such as cognitive behavior therapy for insomnia,” said the study authors.

They conducted a retrospective study to examine the effect of SAS-RLS on insomnia-specific symptoms, comparing patients with the 2 conditions (n = 42; 60% women) and those solely with SAS (n = 160; 71% men). Participants underwent several examinations, including polysomnography (PSG) and a vigilance test (Quatember-Maly), as well as the Regensburg Insomnia Scale (RIS), Epworth Sleepiness Scale (ESS), Beck Depression Inventory-II (BDI-II), and a Morning Questionnaire.

Differences in insomnia-specific symptoms between the 2 groups were calculated using the ANOVA test, with secondary analyses examining the differences in daytime sleepiness and depression.

In the study findings, RIS scores in patients with SAS-RLS were markedly higher (P = .005), with significant differences found in the items “I wake up too early,” “I wake up from the slightest sound,” “I feel that I have not slept all night,” “I think a lot about my sleep,” and “I am afraid to go to bed because of my disturbed sleep.” Additionally, significant differences were seen in the Periodic Limb Movements (PLM) Index (P = .04) and PLM Arousal Index (P <.0005) between groups.

However, patients with SAS-RLS and SAS did not differ in any PSG parameters, as well as in ESS, BDI-II, FZN, the morning questionnaire responses, and the Quatember-Maly vigilance test.

“To our knowledge, this is the first study showing a higher incidence of insomnia-specific symptoms, such as sleep-related worries, in patients suffering from both. The question whether disturbed sleep quality is caused by RLS, SAS, or insomnia disorder cannot be cleared in this study and should be clarified by further research,” said the study authors.

Reference

Pistorius F, Geisler P, Wetter TC, Crönlein T. Sleep apnea syndrome comorbid with and without restless legs syndrome: differences in insomnia specific symptoms [published online April 25, 2020]. Sleep Breath. doi: 10.1007/s11325-020-02063-8.