title: High Prevalence of Orthostatic Dysregulation among Circadian Rhythm Disorder Patients.
abstract: Patients with circadian rhythm sleep disorders (CRSDs) often have coincidence of orthostatic dysregulation (OD). Both disorders have many common clinical features. However, the prevalence of OD in patients with CRSD has not been examined.
  
  
  
  Thirty-eight patients with CRSD with either delayed sleep phase disorder or free-running disorder were tested for OD using the new orthostatic test, which was originally established by Tanaka et al. (< 20 years) and the Schellong test, i.e., the active standing test (≥ 20 years).
  
  
  
  The overall prevalence of OD in patients with CRSD was 57.9% (22/38), and prevalence of OD was 70% in patients under 20 years of age (14/20). These rates exceed the previously reported values in adolescents aged 14-15 years (15%), regarded as the age with highest OD prevalence. Prevalence was not significantly associated with CRSD severity and medications used.
  
  
  
  We observed a high prevalence of OD in patients with CRSD, suggesting some relationship between CRSD and OD. Large-scale case-control studies are warranted to investigate the underlying mechanisms for this comorbidity.
authors: Department of Psychiatry, Fujita Health University School of Medicine, Aichi, Japan.
authors: Akiko
authors: A
authors: Tsuchiya
authors: Department of Psychiatry, Fujita Health University School of Medicine, Aichi, Japan.
authors: Tsuyoshi
authors: T
authors: Kitajima
authors: Department of Psychiatry, Fujita Health University School of Medicine, Aichi, Japan.|Health Support Center, Nagoya Institute of Technology, Aichi, Japan.
authors: Satoe
authors: S
authors: Tomita
authors: Department of Psychiatry, Fujita Health University School of Medicine, Aichi, Japan.
authors: Yuichi
authors: Y
authors: Esaki
authors: Department of Psychiatry, Fujita Health University School of Medicine, Aichi, Japan.
authors: Marina
authors: M
authors: Hirose
authors: Department of Psychiatry, Fujita Health University School of Medicine, Aichi, Japan.
authors: Nakao
authors: N
authors: Iwata
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D015897:Comorbidity; D005260:Female; D006801:Humans; D007024:Hypotension, Orthostatic / Q000453:epidemiology*; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012720:Severity of Illness Index; D020178:Sleep Disorders, Circadian Rhythm / Q000453:epidemiology*; D055815:Young Adult
keywords: circadian rhythm sleep disorders; orthostatic dysregulation; prevalence