Psychosocial factors and the disorders of GI function: what is the link?

Design of psychosocial factors questionnaires: a systematic measurement approach

BACKGROUND

Evaluation of psychosocial factors requires instruments that measure dynamic complexities. This study explains the design of a set of questionnaires to evaluate work and non-work psychosocial risk factors for stress-related illnesses.

METHODS

The measurement model was based on a review of literature. Content validity was performed by experts and cognitive interviews. Pilot testing was carried out with a convenience sample of 132 workers. Cronbach's alpha evaluated internal consistency and concurrent validity was estimated by Spearman correlation coefficients.

RESULTS

Three questionnaires were constructed to evaluate exposure to work and non-work risk factors. Content validity improved the questionnaires coherence with the measurement model. Internal consistency was adequate (α = 0.85-0.95). Concurrent validity resulted in moderate correlations of psychosocial factors with stress symptoms.

CONCLUSIONS

Questionnaires' content reflected a wide spectrum of psychosocial factors sources. Cognitive interviews improved understanding of questions and dimensions. The structure of the measurement model was confirmed.

Activation of corticotropin-releasing factor receptor 2 mediates the colonic motor coping response to acute stress in rodents

BACKGROUND & AIMS

Corticotropin-releasing factor receptor-1 (CRF(1)) mediates the stress-induced colonic motor activity. Less is known about the role of CRF(2) in the colonic response to stress.

METHODS

We studied colonic contractile activity in rats and CRF(2)-/-, CRF-overexpressing, and wild-type mice using still manometry; we analyzed defecation induced by acute partial-restraint stress (PRS), and/or intraperitoneal injection of CRF ligands. In rats, we monitored activation of the colonic longitudinal muscle myenteric plexus (LMMP) neurons and localization of CRF(1) and CRF(2) using immunohistochemical and immunoblot analyses. We measured phosphorylation of extracellular signal-regulated kinase 1/2 by CRF ligands in primary cultures of LMMP neurons (PC-LMMPn) and cyclic adenosine monophosphate (cAMP) production in human embryonic kidney-293 cells transfected with CRF(1) and/or CRF(2).

RESULTS

In rats, a selective agonist of CRF(2) (urocortin 2) reduced CRF-induced defecation (>50%), colonic contractile activity, and Fos expression in the colonic LMMP. A selective antagonist of CRF(2) (astressin(2)-B) increased these responses. Urocortin 2 reduced PRS-induced colonic contractile activity in wild-type and CRF-overexpressing mice, whereas disruption of CRF(2) increased PRS-induced colonic contractile activity and CRF-induced defecation. CRF(2) colocalized with CRF(1) and neuronal nitric oxide synthase in the rat colon, LMMP, and PC-LMMPn. CRF-induced phosphorylation of extracellular signal-regulated kinase in PC-LMMPn; this was inhibited or increased by a selective antagonist of CRF(1) (NBI35965) or astressin(2)-B, respectively. The half maximal effective concentration, EC(50), for the CRF-induced cAMP response was 8.6 nmol/L in human embryonic kidney-293 cells that express only CRF(1); this response was suppressed 10-fold in cells that express CRF(1) and CRF(2).

CONCLUSIONS

In colon tissues of rodents, CRF(2) activation inhibits CRF(1) signaling in myenteric neurons and the stress-induced colonic motor responses. Disruption of CRF(2) function impairs colonic coping responses to stress.

Prevalence of functional gastrointestinal disorders in patients with fibromyalgia and the role of psychologic distress

BACKGROUND & AIMS

Fibromyalgia is a rheumatologic disorder associated with somatic and psychologic conditions. Although fibromyalgia is associated with irritable bowel syndrome, its relationship with other functional gastrointestinal disorders (FGID) is unclear. We evaluated the prevalence of FGID in patients with fibromyalgia and the role of psychologic factors in this relationship.

METHODS

From a Spanish population, 100 patients with fibromyalgia and 100 matched controls completed the Rome II Integrative Questionnaire to assess the prevalence of FGID and the Symptom Checklist-90 Revised (SCL-90R) to evaluate psychologic distress. Patients completed the Fibromyalgia Impact Questionnaire to evaluate the overall impact of fibromyalgia and controls filled out the Chronic Widespread Pain Questionnaire to detect potential cases of fibromyalgia.

RESULTS

Ninety-three percent of the total study population was female, with a mean age of 50 years. We identified 6 cases of widespread pain among controls. The average Fibromyalgia Impact Questionnaire score for patients was 67.28 +/- 14.25. All gastrointestinal symptoms except for vomiting were more frequent in patients. Ninety-eight percent of patients with fibromyalgia had at least one FGID, compared with only 39% of controls. Fibromyalgia was correlated most highly with irritable bowel syndrome. Patients presented with significantly higher scores of psychologic distress than controls, especially those with fecal incontinence.

CONCLUSIONS

There is a prevalence of FGID in patients with fibromyalgia and a wider distribution of such symptoms along the gastrointestinal tract compared with controls. We propose that an increased degree of psychologic distress in these patients predisposes them to FGID, especially significant for anorectal syndromes.

No difference in symptoms of irritable bowel syndrome between healthy subjects and patients with recurrent depression in remission

There is bidirectional comorbidity between anxiety/depression and irritable bowel syndrome (IBS). To investigate the prevalence of IBS symptoms, and factors associated with gastrointestinal symptoms in patients with recurrent depressive disorder. Patients (n = 95) with recurrent type of major depression according to DSM-IV criteria and sex- and age-matched controls (n = 190) were sent questionnaires investigating symptoms of IBS [Gastrointestinal Symptom Rating Scale (GSRS)-IBS] and symptoms of anxiety and depression [Hospital Anxiety and Depression Scale (HADS)]. Medical records were checked over a 10-year period for chronic somatic symptoms or diseases. Seventy-three patients with unipolar disorder (mean age 63.6 years SD 13.8; range 23-86 years) and 156 controls (mean age 59.2 years SD 11.6, range 21-85 years) responded. Patients with recurrent depression had higher GSRS-IBS scores and showed a strong correlation between symptoms of IBS and anxiety-depression (r(s) = 0.54; P < 0.001). IBS symptoms were also associated with multiple pain symptoms, higher health-seeking behaviour and selective-serotonin-reuptake inhibitor intake. However, patients with recurrent depression (n = 46) in remission (HADS-Depression score <8) did not have more symptoms of IBS than controls (GSRS-IBS median score 6.0 vs 6.5; P = 0.46). There is a strong association between symptoms of IBS and symptoms of anxiety and depression, whereas depressive patients in remission do not have more IBS symptoms than controls.

Detailed characterization of epidemiology of uninvestigated dyspepsia and its impact on quality of life among African Americans as compared to Caucasians

BACKGROUND AND AIMS

We wished to study the prevalence as well as the sociodemographic characteristics and quality of life (QoL) of African American patients with uninvestigated dyspepsia (UD) among the population at large and compare it to the Caucasians.

METHODS

A total of 990 adults from nine different sites in the Jackson, Mississippi metropolitan area (670 African Americans and 320 Caucasians), completed self-administered questionnaires providing sociodemographic information, and details regarding bowel habits and associated symptoms for diagnosing the presence or absence of UD based on ROME II criteria. QoL was assessed by the SF-12 questionnaire.

RESULTS

Of the 990 participants 247 had UD, giving a total sample prevalence of 24.9% (African Americans = 24.3%, Caucasians = 26.2%). Adjusting for other risk factors in a reduced logistic regression model, we found female sex (OR 1.8; CI 1.2-2.6; p < 0.01), lower education (p < 0.01), and larger size of household (p = 0.01) to be important correlates of UD prevalence whereas the lower household income showed a trend toward statistical significance (p = 0.057). Using the adjusted odds ratio as an estimate of relative risk, Caucasians were 1.5 (95% CI = 11.1-2.1; p = 0.017) more likely than African Americans to have UD. In terms of an index for QoL on SF-12 (possible score = 1-44, with 44 being ideal), the adjusted mean score was significantly lower for adults with UD compared to non-UD adults (30.4 vs 35.0; p < 0.01). However, there was no difference in impairment of life in Caucasians versus African Americans (32.9 vs 32.5; p = 0.36).

CONCLUSIONS

UD occurs less frequently among African Americans. While UD affects QoL among both Caucasians and African Americans, the degree of impairment is similar.

Increased prevalence of functional gastrointestinal disorders in panic disorder: clinical and theoretical implications

BACKGROUND

Functional gastrointestinal disorders (FGID) are a group of disorders characterized by recurrent gastrointestinal distress for which no structural or biochemical cause can be discerned. Irritable bowel syndrome (IBS) is an FGID estimated to affect 10% to 25% of the United States population. IBS occurs in over 40% of individuals with panic disorder, and in patients with IBS, 25% to 30% have panic disorder, which has led to speculation about possible shared pathophysiology between the two. Less is known about the prevalence of other FGID in individuals with panic disorder.

OBJECTIVE

The purpose of this study was to examine the prevalence of IBS and all the other FGID in patients with current Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) panic disorder.

INTRODUCTION

We assessed FGIDs in 73 treatment-seeking DSM-IV panic disorder patients via the Diagnostic Interview Questions for Functional Gastrointestinal Disorders and made descriptive comparisons with a large convenience sample from an already-completed United States Household Survey (USHS), which employed the same diagnostic criteria.

RESULTS

The prevalence of IBS and other FGIDs in both men and women with panic disorder were substantially higher than in the USHS respondents. Women with panic disorder had significantly more functional chest pain than men, but there was no gender difference in IBS. With the exception of functional anorectal and biliary disorders, the FGID prevalences were comparatively higher in panic disorder versus the USHS respondents.

DISCUSSION

This survey supports earlier reports of a high prevalence of IBS in individuals with panic disorder and also suggests that the prevalence of several other FGIDs were comparatively high as well. Methodological limitations precluded direct statistical analysis. It may be that commonly overlapping psychiatric and often-painful FGIDs, and extra-intestinal disorders increase the risk for comorbidity in already-affected individuals via shared pathophysiology. One potential model for which there is some evidence for a role in stress, panic disorder, FGIDs and several extra-intestinal functional conditions is dysregulation of corticotropin-releasing factor function.

CONCLUSION

The prevalence of FGIDs in DSM-IV panic disorder was comparatively higher than in USHS respondent community sample, which used similar FGID diagnostic criteria. The cause for the apparent close association of panic disorder with FGID may represent shared pathophysiology. Increased understanding of the mechanism of the overlap may allow for improved treatment of the significant proportion of the population suffering from comorbid psychiatric and functional medical conditions.

Expression of type 1 corticotropin-releasing factor receptor in the guinea pig enteric nervous system

Reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, electrophysiological recording, and intraneuronal injection of the neuronal tracer biocytin were integrated in a study of the functional expression of corticotropin-releasing factor (CRF) receptors in the guinea pig enteric nervous system. RT-PCR revealed expression of CRF1 receptor mRNA, but not CRF2, in both myenteric and submucosal plexuses. Immunoreactivity for the CRF1 receptor was distributed widely in the myenteric plexus of the stomach and small and large intestine and in the submucosal plexus of the small and large intestine. CRF1 receptor immunoreactivity was coexpressed with calbindin, choline acetyltransferase, and substance P in the myenteric plexus. In the submucosal plexus, CRF1 receptor immunoreactivity was found in neurons that expressed calbindin, substance P, choline acetyltransferase, or neuropeptide Y. Application of CRF evoked slowly activating depolarizing responses associated with elevated excitability in both myenteric and submucosal neurons. Histological analysis of biocytin-filled neurons revealed that both uniaxonal neurons with S-type electrophysiological behavior and neurons with AH-type electrophysiological behavior and Dogiel II morphology responded to CRF. The CRF-evoked depolarizing responses were suppressed by the CRF1/CRF2 receptor antagonist astressin and the selective CRF1 receptor antagonist NBI27914 and were unaffected by the selective CRF2 receptor antagonist antisauvagine-30. The findings support the hypothesis that the CRF1 receptor mediates the excitatory actions of CRF on neurons in the enteric nervous system. Actions on enteric neurons might underlie the neural mechanisms by which stress-related release of CRF in the periphery alters intestinal propulsive motor function, mucosal secretion, and barrier functions.