The Gastrointestinal Pain Pointer: A Valid and Innovative Method to Assess Gastrointestinal Symptoms.

Abdominal pain is a chronic condition experienced by approximately 20% of individuals in the United States. The purpose of the study was to assess the validity of the Gastrointestinal Pain Pointer as a measure of abdominal pain intensity. A prospective longitudinal time-series study design was utilized. The sample included 93 outpatients (58.1% female). Participants met Rome III criteria for irritable bowel syndrome (n = 32) or were healthy controls (n = 61). The Gastrointestinal Pain Pointer, a new electronic pain assessment tool, was used to assess self-reported abdominal pain intensity among participants before and after ingestion of an intestinal permeability test solution across 11 time points over a 5-hour time period. The results were compared with the Short-Form McGill Pain Questionnaire. The Gastrointestinal Pain Pointer was found to be valid in the assessment of abdominal pain intensity. The tool is a novel and valid measure of abdominal pain intensity that enhances the ability for clinicians to better quantify, in real time, patient-related pain outcomes for both clinical care and research.

Sleep quality, BDNF genotype and gene expression in individuals with chronic abdominal pain.

BACKGROUND: Sleep quality and genetics may contribute to the etiology of gastrointestinal (GI) symptoms. Individuals with impaired sleep often have a number of associated symptoms including chronic abdominal pain (CAP). The current study examined the interactions of brain-derived neurotrophic factor (BDNF) genotype with sleep quality in persons with CAP and healthy controls. In addition, associations among sleep quality, BDNF genotype, and gene expression were explored in the participants. METHODS: Data were collected on 59 participants (46% male, 61% White, 26.9 ± 6.6 years; CAP (n=19) and healthy controls (n=40)). Participants with CAP reported poorer sleep quality compared to healthy controls. BDNF genotype, categorized as Val/Val homozygotes versus the Met carriers. RESULTS: Microarray analysis found twenty-four differentially expressed genes by a two-fold magnitude in participants with poor sleep quality compared to good sleep quality, and seven differentially expressed genes comparing CAP to healthy control. Three specific genes in the pain group overlap with sleep quality, including insulin-like growth factor 1 (IGF1), spermatogenesis associated serine-rich 2-like (SPATS2L), and immunoglobulin heavy constant gamma 1 or mu (IGHG1/// IGHM). BDNF was shown to have an interaction effect with GI and sleep symptoms. CONCLUSIONS: Participants with CAP reported poor sleep quality compared to healthy controls. The role of the BDNF Met allele on differential gene expression was not distinct as main factor, but impacted interactions with sleep quality and CAP. Down-regulation of IGF1, SPATS2L, and IGHG1 expression may be related to the etiology of poor sleep quality and CAP. TRIAL REGISTRATION: Clinicaltrial.gov # NCT00824941.

Gastrointestinal permeability in patients with irritable bowel syndrome assessed using a four probe permeability solution.

BACKGROUND: Abnormal gastrointestinal permeability has been linked to irritable bowel syndrome (IBS). The lactulose-to-mannitol ratio is traditionally used to assess small intestine permeability while sucralose and sucrose are used to assess colonic and gastric permeability respectively. We used a single 4-probe test solution to assess permeability throughout the gastrointestinal tract in IBS patients and healthy controls by measuring the recovery of the probes in urine after ingestion using a modified liquid chromatography mass spectrometry protocol. METHODS: Fasting participants (N=59) drank a permeability test solution (100ml: sucralose, sucrose, mannitol, and lactulose). Urine was collected over a 5-h period and kept frozen until analysis. Urinary sugar concentrations were measured using a liquid chromatography/triple quadruple mass spectrometer. RESULTS: Colonic permeability was significantly lower in IBS patients when compared to healthy controls (p=0.011). Gastric and small intestinal permeability did not significantly differ between the groups. CONCLUSIONS: The study demonstrates the clinical potential of this non-invasive method for assessing alterations in gastrointestinal permeability in patients with IBS.

Symptom Status Predicts Patient Outcomes in Persons with HIV and Comorbid Liver Disease.

Persons living with human immunodeficiency virus (HIV) are living longer; therefore, they are more likely to suffer significant morbidity due to potentially treatable liver diseases. Clinical evidence suggests that the growing number of individuals living with HIV and liver disease may have a poorer health-related quality of life (HRQOL) than persons living with HIV who do not have comorbid liver disease. Thus, this study examined the multiple components of HRQOL by testing Wilson and Cleary's model in a sample of 532 individuals (305 persons with HIV and 227 persons living with HIV and liver disease) using structural equation modeling. The model components include biological/physiological factors (HIV viral load, CD4 counts), symptom status (Beck Depression Inventory II and the Medical Outcomes Study HIV Health Survey (MOS-HIV) mental function), functional status (missed appointments and MOS-HIV physical function), general health perceptions (perceived burden visual analogue scale and MOS-HIV health transition), and overall quality of life (QOL) (Satisfaction with Life Scale and MOS-HIV overall QOL). The Wilson and Cleary model was found to be useful in linking clinical indicators to patient-related outcomes. The findings provide the foundation for development and future testing of targeted biobehavioral nursing interventions to improve HRQOL in persons living with HIV and liver disease.

Stress and gene expression of individuals with chronic abdominal pain.

BACKGROUND: Research examining the role of stress in gastrointestinal (GI) symptoms such as chronic abdominal pain (CAP) is controversial. The purpose of this study was to examine the expression of genes involved in metabolic stress and toxicity in men and women with high and low levels of perceived stress with and without CAP. METHODS: Data and samples were collected and the expression of genes involved in metabolic stress and toxicity was analyzed in 26 individuals who had consented to participate in a natural history protocol. Subjects completed the 10-item Perceived Stress scale (PSS). Fasting participants' peripheral whole blood was collected for proteomic and genomic studies. Polymerase chain reaction (PCR) array was used to analyze the expression of 84 key genes involved in human stress and toxicity plus 5 housekeeping genes. Plasma interleukin-1 alpha (IL-1α) protein was quantified via enzyme-linked immunosorbent assay (ELISA). RESULTS: Interleukin-1 alpha gene (IL1A) was upregulated in females with high stress versus females with low stress by 2.58-fold (95% CI [0.88, 4.28]). IL1A was upregulated in participants with high stress and CAP versus those with low stress and CAP by 3.47-fold (95% CI [1.14, 5.80]). CONCLUSIONS: An upregulation of the gene coding the pro-inflammatory cytokine IL-1α suggests that the mechanism behind stress-related changes in GI symptoms is pro-inflammatory in nature. The results of this study contribute to the knowledge of the mechanism behind stress-related CAP symptoms and gender differences associated with these disorders.

Validation of the MOS-HIV as a measure of health-related quality of life in persons living with HIV and liver disease.

BACKGROUND: Management of human immunodeficiency virus (HIV) infection with potent antiretroviral medication has transformed HIV into a chronic condition and has shifted much of the burden of disease to co-morbid conditions such as liver disease (LD). LD alone has been shown to have a significant effect on one's health-related quality of life (HRQOL). Clinical evidence suggests that the growing number of persons living with HIV+LD may have a poorer HRQOL than persons with HIV without LD. To date, the widely accepted instrument to assess HRQOL, Medical Outcomes Study-HIV Health Survey (MOS-HIV), has not been evaluated for reliability and validity in a population of HIV-infected persons with LD. METHODS: HRQOL was prospectively assessed using the MOS-HIV in a sample of 532 HIV-infected adults on antiretroviral therapy (n=305 HIV and n=227 HIV+LD). In addition, participants completed standardized questionnaires of sociodemographics and co-morbid conditions. RESULTS: The psychometric properties of the MOS-HIV were supported by testing reliability and construct, convergent, discriminative, and predictive validity. The MOS-HIV discriminated between those persons living with HIV with and without LD on the basis of the physical function subscale scores (p=0.018). CONCLUSION: This study found the MOS-HIV valid and reliable instrument in persons with HIV+LD.