Sleep disturbances in patients with primary Sjögren's syndrome.

A standardized sleep questionnaire was used to investigate the sleeping habits of outpatients with primary Sjögren's syndrome (pSS) (n = 40) and RA (n = 42). Sleep deficit (difference between need of sleep and actual sleeping time) was significantly higher in patients with pSS when compared with healthy matched controls (P < 0.0001), and with patients suffering from RA (P < 0.001). When trying to fall asleep, patients with pSS were significantly more often disturbed by muscular tension (45%) and restless legs (24%), than patients with RA (12%, P < 0.01 and 2%, P < 0.01), and they were also significantly more troubled by nocturnal pain than patients with RA (P < 0.01). The pSS group reported significantly more disturbing by awakening during the night and was awake for longer periods than the RA group. Fatigue was a significantly more frequent complaint in patients with pSS. Polysomnography showed that all recorded patients (n = 10) had some sleep disturbances; reduced sleep efficiency (n = 8), increased number of awakenings (n = 5) and increased wakefulness surrounded by sleep (n = 9). Five patients had alpha intrusion in their sleep EEGs. The sleep disturbances seen in patients with primary Sjögren's syndrome may contribute to the fatigue associated with this disease.