Sleep patterns among patients with chronic fatigue: a polysomnography based study

Abstract

Objectives: To evaluate sleep disorders in patients with chronic fatigue. Methods: Patients were referred to Myalgic Encephalomyelitis (ME)/ Chronic Fatigue Syndrome (CFS)-rehabilitation for suspected diagnosis ME/CFS. Criteria for further referral to full night polysomnography (PSG) were: excessive sleep complaints in clinically created ME/CFS symptoms questionnaire, medical history and/or Epworth sleepiness scale (ESS) ≥10. Results: 78 patients underwent PSG, 66 women and 12 men, mean age 48.6 9.9, mean BMI 25.4 4.5. Results showed that more than half of all patients had normal sleep, meanwhile 14 (18.9%) were diagnosed with obstructive sleep apnea (OSA): 7 had mild degree, 4 had moderate, and 3 had severe. 11 (14.9%) patients got the diagnosis of periodic limb movement disorder (PLMD), and in 5 cases suspected insomnia. Restless legs syndrome was diagnosed in more than one third patients (n = 32, 43.2%). Patients were further subgrouped into those who fulfilled diagnosis for ME/CFS, n = 55, (70.5%) and those who did not, n = 23 (29.5%). The prevalence of sleep disorders was similar in both groups. Non-ME/CFS group had significantly higher respiratory (P = 0.01) and total arousal (P = 0.009) indexes, higher respiratory disturbance (P = 0.01) and oxygen desaturation indexes (P = 0.009), as compared with ME/CFS group. There were no significant differences in ESS score and the rest of PSG measures between the groups. Conclusions: More than half of chronically fatigued patients had normal sleep macrostructure. About one third of the study population was diagnosed with treatable sleep disorders such OSA or PLMD. Few significant differences were found between ME/CFS and non- ME/CFS patients.