title: Sleep quality in rheumatoid arthritis, and its association with disease activity in a Korean population.
abstract: OBJECTIVE
  The aim of this study was to compare the sleep quality between rheumatoid arthritis (RA) patients and healthy controls; and to evaluate the relationship between RA disease activity and sleep quality in Korea.
  
  
  METHODS
  A total of 130 RA patients and 67 age- and sex-matched healthy controls were enrolled in a comparative study of sleep quality using the Pittsburgh Sleep Quality Index (PSQI). Age, gender, concomitant medication, erythrocyte sedimentation rate, serum C-reactive protein, Beck Depression Inventory second edition (BDI-II), 28 joints disease activity score (DAS28), pain visual analog scale (VAS), and PSQI were analyzed as covariates. We also analyzed the sleep quality of RA patients according to the disease activity (DAS28 ≤ 3.2, 3.2 < DAS28 < 5.1, and DAS28 ≥ 5.1, respectively).
  
  
  RESULTS
  The total PSQI score and the frequency of poor sleep quality, were higher in the RA patients (5.62 ± 4.19, 38.5%) than in the control subjects (3.57 ± 2.17, 13.4%). The patients with poor sleep quality (PSQI > 5) were older and had a higher BDI-II and VAS score than the patients without sleep disturbance (PSQI ≤ 5). The score in subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbance, daytime dysfunction, total PSQI, and frequency of poor sleep quality were increased when RA activity was high.
  
  
  CONCLUSIONS
  Sleep disturbance was observed in RA patients (38.5%), and high RA disease activity was associated with poor sleep quality in Korea.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Keimyung University Dongsan Medical Center, Daegu, Korea.
authors.forename: Chang-Nam
authors.initials: CN
authors.lastname: Son
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Keimyung University Dongsan Medical Center, Daegu, Korea.
authors.forename: Go
authors.initials: G
authors.lastname: Choi
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Keimyung University Dongsan Medical Center, Daegu, Korea.
authors.forename: So-Yeon
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Keimyung University Dongsan Medical Center, Daegu, Korea.
authors.forename: Ji-Min
authors.initials: JM
authors.lastname: Lee
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Keimyung University Dongsan Medical Center, Daegu, Korea.
authors.forename: Tae-Han
authors.initials: TH
authors.lastname: Lee
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Keimyung University Dongsan Medical Center, Daegu, Korea.
authors.forename: Hye-Jin
authors.initials: HJ
authors.lastname: Jeong
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Keimyung University Dongsan Medical Center, Daegu, Korea.
authors.forename: Chang-Gyu
authors.initials: CG
authors.lastname: Jung
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Keimyung University Dongsan Medical Center, Daegu, Korea.
authors.forename: Ji-Min
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Neurology, Keimyung University Dongsan Medical Center, Daegu, Korea.
authors.forename: Yong-Won
authors.initials: YW
authors.lastname: Cho
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Keimyung University Dongsan Medical Center, Daegu, Korea.
authors.forename: Sang-Hyon
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000208:ethnology / Q000503:physiopathology*; D044466:Asian People; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D003863:Depression / Q000175:diagnosis / Q000208:ethnology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D012720:Severity of Illness Index; D012890:Sleep; D012893:Sleep Wake Disorders / Q000175:diagnosis / Q000208:ethnology / Q000503:physiopathology*; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Depression; Disease activity; Rheumatoid arthritis; Sleep quality