title: Heterogeneity of symptom pattern, psychosocial factors, and pathophysiological mechanisms in severe functional dyspepsia.
abstract: OBJECTIVE
  Categorization of functional dyspepsia into subgroups is based on expert opinion according to (dominant) symptoms or on underlying pathophysiological mechanisms. We used an evidence-based approach to the determination of subtypes of functional dyspepsia.
  
  
  METHODS
  Consecutive functional dyspepsia patients were recruited from a tertiary referral center. The following were performed: (1) exploratory (EFA) and confirmatory factor analysis (CFA) of symptom patterns in a large group of patients with functional dyspepsia; (2) external validation of these factors by the determination of their association pattern with physio- and psychopathological mechanisms, and with health-related quality of life and sickness behavior; and (3) cluster analysis of their distribution in this population.
  
  
  RESULTS
  Both EFA and CFA do not support the existence of functional dyspepsia as a homogeneous (unidimensional) condition. A 4-factor model is found to be valid, with differential distribution within the patient population according to cluster analysis. Factor 1 is characterized by nausea, vomiting, early satiety, and weight loss and factor 2 by postprandial fullness and bloating. Both factor 1 and 2 are associated with delayed emptying, but only factor 1 is associated with younger age, female sex, and sickness behavior. Factor 3 is characterized by pain symptoms and associated with gastric hypersensitivity and several psychosocial dimensions including medically unexplained symptoms and health-related quality of life dimensions. Factor 4, characterized by belching, is also associated with hypersensitivity, but is unrelated to psychosocial dimensions.
  
  
  CONCLUSIONS
  In a tertiary care population, functional dyspepsia is a heterogeneous condition characterized by 4 major dimensions differentially associated with psychopathological and physiopathological mechanisms.
authors.affiliation: Department of Psychiatry, University Hospital Gashuisberg, Leuven, Belgium.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Fischler
authors.forename: Jan
authors.initials: J
authors.lastname: Tack
authors.forename: Véronique
authors.initials: V
authors.lastname: De Gucht
authors.forename: Z' Iv
authors.initials: ZI
authors.lastname: Shkedy
authors.forename: Philippe
authors.initials: P
authors.lastname: Persoons
authors.forename: Dorine
authors.initials: D
authors.lastname: Broekaert
authors.forename: Geert
authors.initials: G
authors.lastname: Molenberghs
authors.forename: Jozef
authors.initials: J
authors.lastname: Janssens
mesh_terms: D015746:Abdominal Pain / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D000328:Adult; D016000:Cluster Analysis; D004415:Dyspepsia / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D019317:Evidence-Based Medicine; D005746:Gastric Emptying; D006801:Humans; D008297:Male; D009325:Nausea / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D009497:Neurotic Disorders / Q000150:complications / Q000523:psychology; D009819:Office Visits; D011584:Psychology; D011788:Quality of Life; D012720:Severity of Illness Index; D018582:Sick Leave; D013001:Somatoform Disorders / Q000150:complications / Q000523:psychology; D011795:Surveys and Questionnaires; D014839:Vomiting / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology