Sleep Pattern in Patients with β-Thalassemia Minor.

Introduction: Although sleep disturbances, anxiety, and sadness are some of the most common symptoms in patients with chronic anemia, there is little knowledge about sleep structures in patients with chronic anemia such as thalassemia. The aim of this study is to investigate sleep structure in patients with beta-thalassemia minor.

Methods: Seventeen drug free subjects with beta-thalassemia minor and age-matched healthy subjects were enrolled in the study. The patients were diagnosed by complete blood count including reticulocyte count and hemoglobin electrophoresis. In addition, blood smear, erythrocyte sedimentation rate, serum level of urea, creatinine, indirect bilirubin, lactate dehydrogenase, ferritin, folate, vitamin B12, and thyroid hormones were determined. The other causes of anemia were ruled out. Subjects also were screened for excessive daytime sleepiness with the Epworth sleepiness scale, and for insomnia using insomnia severity index. All subjects slept in laboratory for two consecutive nights. First night served as adjustment nights. The second night results were used for analysis. Their sleep patterns were compared with healthy normal controls. Sleep was recorded and scored according to the criteria of Rechtschafffen and Kales.

Results: Four female and thirteen male patients (mean age, 26.1 ± 5.9 years) completed both nights of sleep recordings. In patients groups, one patient complained snoring and daytime sleepiness. Nine of them complained daytime weakness. Ten patients were anemic (Hb < 13,2 g/dL for men, <11,7 g/dL for women). In polysomnographic investigation, the patients with β-thalassemia minor showed increased total sleep time, sleep period time, PLM index and the increased percentage of REM sleep. The percentage of stage 4, and REM latency are decreased. Sleep fragmentation and periodic leg movement syndrome (PLMS) have been reported.

Conclusion: The disturbances of sleep continuity was prominent finding in this polysomnographic study. They also showed decreased REM latency and the increased percentage of REM sleep, although they didn’t have major depressive disorders.