title: The association between irritable bowel syndrome and the coexistence of depression and insomnia.
abstract: The individual occurrence of depression or insomnia is a risk factor for irritable bowel syndrome (IBS), but few researchers have evaluated the association between comorbid depression and insomnia and IBS. The aim of the present study is to explore the relationship between IBS and the coexistence of depression and insomnia in a Korean population-based cohort study.
  
  
  
  A total of 3429 individuals who were enrolled in the Korean Genome and Epidemiology Study were analysed. Of the participants, 10.9% (n=374) were diagnosed with IBS based on the Rome II criteria. Regarding depressive symptoms, subjects were sub-divided into three groups based on the Beck Depression Inventory (BDI) score. Insomnia was defined as a positive response to at least one of three questions on sleep states.
  
  
  
  The odds ratio (OR) of IBS increased proportionally as depressive symptoms worsened (OR: 1.64; 95% CI: 1.21-2.23 in middle tertile and OR: 2.61; 95% CI: 1.92-3.55 in highest tertile). Subjects with insomnia showed a higher OR of IBS than those without insomnia (OR: 1.81; 95% CI: 1.44-2.27). In the joint analysis of BDI and insomnia, the odds for IBS were significantly higher in all BDI tertiles with insomnia than in the corresponding BDI tertiles without insomnia. There was no significant interaction effect of BDI tertile and insomnia on IBS.
  
  
  
  The presence of both depression and insomnia is significantly associated with IBS compared to each individual occurrence. Further prospective investigations are needed to explore possible causality between comorbid depression and insomnia and IBS.
authors.affiliation: Institute of Human Genomic Study, College of Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea.
authors.forename: Seung Ku
authors.initials: SK
authors.lastname: Lee
authors.affiliation: Institute of Human Genomic Study, College of Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea.
authors.forename: Dae Wui
authors.initials: DW
authors.lastname: Yoon
authors.affiliation: Institute of Human Genomic Study, College of Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea.
authors.forename: Sunghee
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Biomedical Laboratory Science, College of Health Science, Jungwon University, Chung-Buk, Republic of Korea.
authors.forename: Jinkwan
authors.initials: J
authors.lastname: Kim
authors.affiliation: Institute of Human Genomic Study, College of Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea; Korea Health Promotion Foundation, 24th FL Namsam Square Bldg, Seoul 04554, Korea.
authors.forename: Kyung-Mee
authors.initials: KM
authors.lastname: Choi
authors.affiliation: Institute of Human Genomic Study, College of Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea; Department of Pulmonary, Sleep and Critical Care Medicine, College of Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea. Electronic address: chol-shin@korea.ac.kr.
authors.forename: Chol
authors.initials: C
authors.lastname: Shin
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003866:Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D010555:Personality Inventory / Q000706:statistics & numerical data; D011594:Psychometrics; D056910:Republic of Korea; D012307:Risk Factors; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D013223:Statistics as Topic
keywords: Depression; Insomnia; Irritable bowel syndrome; Rome II