Heterogeneity of symptom pattern, psychosocial factors, and pathophysiological mechanisms in severe functional dyspepsia.
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.
Fischler
Benjamin
B
Department of Psychiatry, University Hospital Gashuisberg, Leuven, Belgium.
Tack
Jan
J
De Gucht
Véronique
V
Shkedy
Z' Iv
ZI
Persoons
Philippe
P
Broekaert
Dorine
D
Molenberghs
Geert
G
Janssens
Jozef
J
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