Objective: The standard replacement therapy in Addison's disease does not restore normal nocturnal levels of the hormones of the hypothalamic-pituitary-adrenal axis. The aim of the study was to describe the prevalence and characteristics of sleep disturbances in patients with Addison's disease.
Methods: Sixty patients completed a self-administered sleep questionnaire and the Epworth Sleepiness Scale (ESS) questionnaire. Activity-based monitoring (actigraph recordings) and sleep diaries were obtained from eight patients.
Results: Thirty-four percent reported weekly sleep disturbances (difficulties falling asleep in 13%; repeated awakenings in 14%; early morning awakenings in 20%). The sleep need was 8.21 h (s.d. 1.34; range 6-14 h), and sleep onset latency was 29 min (s.d. 29, range 2-150 min). Forty percent of the patients were tired during daily activities more than once a week, but the scores of the ESS were 6.0 (s.d. 3.5), which is not higher than normal. The actigraph recordings showed higher sleep efficiency than the subjective recordings.
Conclusion: We did not identify specific sleep disturbances which were characteristic for patients with Addison's disease. Patients with Addison's disease have increased daytime fatigue, but no more daytime sleepiness than normal.