title: Autonomic dysfunction in primary Sjogren's syndrome: a prospective cohort analysis of 154 Korean patients.
abstract: OBJECTIVE
  To determine the prevalence of autonomic dysfunction among Korean patients with primary Sjogren's syndrome (pSS) and its associations with the clinical features of pSS.
  
  
  METHODS
  We analyzed 154 participants from the Korean Initiative of primary Sjogren's Syndrome (KISS) as a prospective pSS cohort and 154 age- and sex-matched healthy controls. A standardized 5-minute, supine, resting heart rate variability (HRV) test was performed, and autonomic dysfunction was defined as standard deviation of normal-to-normal RR intervals (SDNN) < 30 ms in patients < 50 years old and SDNN < 20 ms in patients ≥ 50 years old. The associations between autonomic dysfunction and various clinical features of pSS were analyzed.
  
  
  RESULTS
  The overall autonomic activity in patients with pSS was significantly lower than that in controls. Autonomic dysfunction with the HRV test was observed in 35.7% of the KISS participants and was associated with a higher European League Against Rheumatism Sjogren's Syndrome Patient Reported Index fatigue score (p= 0.024). Raynaud's phenomenon was a more frequent clinical presentation in pSS patients with autonomic dysfunction than in those without autonomic dysfunction (29.4% and 14.4%, respectively;p= 0.048). Decreased parasympathetic activity was observed in 41.6% of pSS patients. No differences were found in the oral and ocular signs of pSS according to the decreased parasympathetic activity.
  
  
  CONCLUSIONS
  In Korean patients with pSS, decreased and imbalanced autonomic activity is prevalent and is associated with fatigue. However, an association between autonomic dysfunction and glandular manifestations was not detected.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jung Hee
authors.initials: JH
authors.lastname: Koh
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
authors.forename: Seung-Ki
authors.initials: SK
authors.lastname: Kwok
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Lee
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
authors.forename: Sung-Hwan
authors.initials: SH
authors.lastname: Park
mesh_terms: D001341:Autonomic Nervous System / Q000503:physiopathology*; D001342:Autonomic Nervous System Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D016022:Case-Control Studies; D005221:Fatigue / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D005260:Female; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D066106:Seoul / Q000453:epidemiology; D012859:Sjogren's Syndrome / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D016683:Supine Position; D013997:Time Factors
keywords: Autonomic nervous system; Fatigue; Heart rate variability; Sjogren’s syndrome