Biomedical subjects

Lin Chang

Publications and source records attributed to Lin Chang.

At least 37 records · Page 2Linked to original sources

PubMed2005

Impact of irritable bowel syndrome on patients' lives: development and psychometric documentation of a disease-specific measure for use in clinical trials.

OBJECTIVE: To develop a disease-specific questionnaire to capture the impact of irritable bowel syndrome (IBS) and its treatment on patients' lives, the Irritable Bowel Syndrome Impact Scale (IBS-IS). PATIENTS AND METHODS: One hundred and fifty-five IBS patients participated (126 (81%) female; age (mean+/-SD) 45.5+/-12.4 years). We developed the initial 39 items from the literature, available IBS-specific instruments and input from physicians, nurses and patients. We deleted IBS-IS items with a high ceiling effect, items that measured a different construct and items showing a high correlation (r>0.90) with another item and with Rasch analysis, leaving 26 items. We then applied exploratory factor analysis to examine domain groupings. Subjects completed the IBS-IS instrument, the Gastrointestinal Symptom Rating Scale for IBS (GSRS-IBS), Short Form-36 (SF-36), Visceral Sensitivity Index (VSI), and Hospital Anxiety and Depression (HAD) scale. Internal consistency, construct validity and discriminate validity were assessed. RESULTS: The 26 items represented five domains: fatigue, impact on daily activities, sleep disturbance, emotional distress and eating habits. The internal consistency reliability for the domains was 0.87 to 0.96. Most associations between similar constructs in the IBS-IS, GSRS-IBS, SF-36, VSI, and HAD were >0.40. Each IBS-IS domain score decreased with increasing IBS symptom severity (P<0.05), and the patients scored >5 score units lower than a US general population scored on all eight SF-36 dimensions. CONCLUSION: The IBS-IS is a short, user-friendly instrument with excellent psychometric properties that has potential usefulness for clinical trials.

Activities of Daily Living↗

PubMed2005

Significance of a glenoid fossa approach for management of extensive lesions in the lateral skull base.

OBJECTIVE: This article is designed to relate our experiences with a glenoid fossa approach for exposing the outer border of extensive lesions in the lateral skull base. MATERIALS AND METHODS: In this series, there were five large paragangliomas with the longest diameter of 6.5 cm in length, one large jugular schwannoma with extratemporal components, and one severe case of petromastoiditis with otogenic pachymeningitis, edema of the temporal lobe, and mental disorder. All lesions of these cases were treated via a glenoid fossa approach combined with other reasonable approaches. RESULTS: The glenoid fossa approach resulted in crucial advantages: 1) it effectively exposes the outer border of extensive lesions in the lateral skull base; 2) it provides safe distal control of the facial nerve and internal carotid artery in the skull base; 3) it obviates the need for anterior transposition or rerouting of the facial nerve; and 4) it obviates sacrifice of the intact middle ear or section the mandibular condyle. There is no postoperative mandibular dysfunction because the mandibular articular capsule and articular tubercle are kept intact. CONCLUSION: On the basis of our experiences, the glenoid fossa approach is a safe, quick, and useful design for adequate exposure of the outer border of extensive lesions in lateral skull base surgery.

Adult↗

PubMed2005

A dose-ranging, phase II study of the efficacy and safety of alosetron in men with diarrhea-predominant IBS.

BACKGROUND: A randomized, double blind, placebo-controlled dose-ranging study was conducted to assess the efficacy of alosetron in men with diarrhea-predominant irritable bowel syndrome (IBS). METHODS: Six hundred and sixty-two men were randomized to treatment with alosetron 0.5, 1.0, 2.0, 4.0 mg, or placebo twice daily for 12 wk, followed by a 4-wk posttreatment period. Adequate relief of IBS pain and discomfort during week 5-12 of the treatment phase was the primary endpoint; secondary endpoints included bowel urgency, stool frequency, and consistency, incomplete evacuation, bloating, and abdominal pain or discomfort. RESULTS: Subjects ranked urgency and abdominal pain as their most bothersome IBS symptoms. The average rate of adequate relief during week 5-12 was significantly higher in the alosetron 1.0 mg twice-daily group compared to placebo (53%vs 40%, p= 0.04), and all doses of alosetron significantly reduced stool consistency scores (p < 0.001) indicating firmer stools. No significant effects of alosetron were seen with regard to urgency, number of bowel movements, bloating, and incomplete evacuation. Constipation was the most common adverse event and occurred in a dose-related manner among subjects receiving alosetron, 9% (0.5 mg twice daily), 15% (1.0 mg twice daily), 11% (2.0 mg twice daily), and 21% (4.0 mg twice daily). No serious adverse events of constipation were reported. One subject in the 0.5 mg twice-daily group had an episode of rectal bleeding suggestive of a possible diagnosis of ischemic colitis. CONCLUSIONS: Alosetron 1 mg twice daily provided adequate relief of IBS pain and discomfort, and improved stool consistency in men with diarrhea-predominant IBS.

Abdominal Pain↗

PubMed2005

Characterization of the alternating bowel habit subtype in patients with irritable bowel syndrome.

BACKGROUND: Due to a wide range of symptom patterns, patients with irritable bowel syndrome (IBS) are often subgrouped by bowel habit. However, the IBS subgroup with alternating bowel habits (IBS-A) has been poorly characterized. OBJECTIVES: (i) To determine a set of bowel habit symptom criteria, which most specifically identifies IBS patients with an alternating bowel habit, (ii) to describe IBS-A bowel symptom patterns, and (iii) to compare clinical characteristics among IBS-A, constipation-predominant (IBS-C), and diarrhea-predominant IBS (IBS-D). METHODS: One thousand one hundred and two Rome I positive IBS patients were analyzed. Three sets of potential criteria for IBS-A were developed and compared by multirater Kappa test. Gastrointestinal, psychological, extraintestinal symptoms, and health-related quality of life were compared in IBS-A, IBS-C, and IBS-D using chi(2) test and analysis of variance (ANOVA). RESULTS: Stool consistency was determined to be the most specific criteria for alternating bowel habits. IBS-A patients reported rapid fluctuations in bowel habits with short symptom flares and remissions. There was a greater prevalence of psychological and extraintestinal symptoms in the IBS-A subgroup compared to IBS-C and IBS-D. No differences were seen between bowel habit subtypes in health-related quality of life. CONCLUSIONS: IBS-A patients have rapidly fluctuating symptoms and increased psychological comorbidity, which should be taken into account for clinical practice and clinical trials.

Adolescent↗

PubMed2004

Salusins promote cardiomyocyte growth but does not affect cardiac function in rats.

Salusin-alpha and -beta are newly found polypeptides that stimulate proliferation, hypotension and bradycardia in vascular smooth muscle cells (VSMCs) and fibroblasts. Propresalusin mRNA is widespread, and positive stains for salusins have been observed in many human tissues such as endothelium and ventricular tissue. To investigate the bio-effect of salusins on cardiovascular function, 20 nmol/kg salusin-alpha or 2 nmol/kg salusin-beta was intravenously (i.v.) injected into rats, and isolated rat hearts were perfused with 10(-12) to 10(-7) mol/l salusin-alpha or -beta. (45)Ca(2+) uptake and (3)H-Leucine incorporation were determined in cultured neonatal rat cardiomyocytes. Neither salusin-a nor -beta affected cardiac function in vivo or in vitro but salusin-beta decreased mean arterial blood pressure (MAP). The polypeptides' stimulation of (45)Ca(2+) uptake and (3)H-Leucine incorporation was concentration-dependent, and the incorporation was inhibited by nicardipine (Nic) and FK-506 [FK; an inhibitor of calcineurin (CaN)]. PD(98059) [PD; inhibitor of mitogen-activated protein kinase (MAPK)] and chelerythrine [inhibitor of protein kinase C (PKC)] inhibited salusin-stimulated (3)H-Leucine incorporation. Endothelin-1 (ET) synergistically increased salusin-induced (45)Ca(2+) uptake. Our results suggest that salusin-alpha and -beta did not directly affect cardiac function in the rat heart but that they improved calcium uptake and protein synthesis in neonatal rat cardiomyocytes through the calcium, calcineurin, MAPK and PKC signal pathways. Salusins may be regulatory factors for myocardial growth and hypertrophy.

Adenosine Triphosphatases↗

PubMed2004

Clinical determinants of health-related quality of life in patients with irritable bowel syndrome.

BACKGROUND: Current guidelines recommend routine assessment of health-related quality of life (HRQOL) in patients with irritable bowel syndrome (IBS). However, physicians rarely have the time to measure HRQOL with the appropriate methodological rigor, and data suggest that HRQOL in patients with IBS is often estimated using inaccurate clinical gestalt. The identification of predictive factors could allow physicians to better assess HRQOL without using misleading clinical clues. We, therefore, sought to identify determinants of HRQOL in patients with IBS. METHODS: We examined 770 patients, 18 years or older, with IBS at a university-based referral center. Subjects completed a symptom questionnaire, the Symptoms Checklist-90 items psychometric checklist, and the 36-Item Short-Form Health Survey. The main outcome was HRQOL as measured by the mental and physical component scores of the 36-Item Short-Form Health Survey. We first developed a list of hypothesis-driven HRQOL predictors, and then performed multivariate regression analysis to measure the independent association of each predictor with HRQOL. RESULTS: Seven factors (r(2) = 0.39) independently predicted physical HRQOL: (1) more than 5 physician visits per year, (2) tiring easily, (3) low in energy, (4) severe symptoms, (5) predominantly painful symptoms, (6) the feeling that there is "something seriously wrong with body," and (7) symptom flares for longer than 24 hours. Eight factors (r(2) = 0.36) independently predicted mental HRQOL: (1) feeling tense, (2) feeling nervous, (3) feeling hopeless, (4) difficulty sleeping, (5) tiring easily, (6) low sexual interest, (7) IBS symptom interference with sexual function, and (8) low energy. CONCLUSIONS: Health-related quality of life in patients with IBS is primarily related to extraintestinal symptoms rather than traditionally elicited gastrointestinal symptoms. These findings suggest that rather than focusing on physiological epiphenomena (stool characteristics and subtype of IBS) and potentially misleading clinical factors (age and disease duration), physicians might be better served to gauge global symptom severity, address anxiety, and eliminate factors contributing to chronic stress in patients with IBS.

Activities of Daily Living↗

PubMed2004

Endogenous hydrogen sulfide regulation of myocardial injury induced by isoproterenol.

Previous work has shown that the endogenous cystathionine gamma-synthase (CSE)/hydrogen sulfide (H(2)S) pathway participates in the regulation of cardiac contraction. We hypothesized that the pathway might participate in the pathophysiological regulation of ischemic heart disease. Isoproterenol injection of rat hearts induced a myocardial ischemic injury model, with reduced myocardial and plasma H(2)S levels, decreased CSE activity, and upregulated CSE gene expression. Exogenous administration of the H(2)S donor NaHS reduced the mortality rate; increased left-ventricular pressure development and left-ventricular-end systolic pressure; and decreased left-ventricular-end diastolic pressure (LVEDP) and subendocardial necrosis, capillary dilatation, leukocytic infiltration, fibroblast swelling, and fibroblastic hyperplasia. As well, production of lipid peroxidation, including myocardial malondialdehyde (MDA), and plasma MDA and conjugated diene, was reduced. Oxidative stress injury is an important mechanism of isoproterenol-induced myocardial injury. In vitro experiments revealed that NaHS might antagonize myocyte MDA production by oxygen-free radicals and that NaHS directly scavenged hydrogen peroxide and superoxide anions. Our results suggest that the endogenous CSE/H(2)S pathway contributes to the pathogenesis of isoproterenol-induced myocardial injury. Administration of exogenous H(2)S effectively protects myocytes and contractile activity, at least by its direct scavenging of oxygen-free radicals and reducing the accumulation of lipid peroxidations.

Alkenes↗

PubMed2004

Sex-based differences in gastrointestinal pain.

Recent interest has focused on sex-related differences in irritable bowel syndrome (IBS) physiology and treatment responsiveness to novel pharmacologic therapies. Similar to a variety of other chronic pain conditions and certain affective disorders, IBS is more prevalent amongst women, both in population-based studies as well as in clinic-based surveys. Non-painful gastrointestinal symptoms, constipation and somatic discomfort are more commonly reported by female IBS patients. While perceptual differences to rectosigmoid stimulation are only observed following repeated noxious stimulation of the gut, sex-related differences in certain sympathetic nervous system (SNS) responses to rectosigmoid stimulation are consistently seen. Consistent with experimental findings in animals, current evidence is consistent with a pathophysiological model which emphasizes sex-related differences in autonomic and antinociceptive responses to certain visceral stimuli.

Animals↗

PubMed2004

Intracranial metastasis of hepatocellular carcinoma: review of 45 cases.

BACKGROUND: Although extrahepatic metastasis of hepatocellular carcinoma (HCC) is not uncommon, intracranial metastasis is relatively rare. METHODS: We reviewed HCC cases admitted in our hospital in the past 16 years, and there were only 45 cases with clinically diagnosed intracranial metastasis. Their age ranged from 14 to 82 years with the peak in the 3rd and 4th decades, which is much younger than the average age of the HCC patients. RESULTS: Of the 45 patients, 39 (39/45, 86.7%) had hepatitis B related and 20 (20/45, 44.4%) had cirrhosis of the liver. Intracranial hemorrhage as the initial manifestation was common in our series (18/45, 40%). Hemiparesis was found in 14 cases, scalp mass in 9 cases, headache in 13 cases, diplopia in 3 cases (1 ultimately became totally blind), homonymous hemianopsia in 2 cases, dysarthria in 3 cases, gait disturbance in 1 case, seizure in 3 cases, and aphasia in 1 case. The modes of therapy for patients with intracranial metastasis included conservative medical treatment only or surgical excision and/or radiotherapy. In this series, elevated AFP was noted in 32 patients, and alpha fetoprotein higher than several thousands was even noted in 30 patients; extraordinary high level (>70000) was also seen in more than one-half of the patients. CONCLUSIONS: HCC patients with intracranial metastasis presented a very poor prognosis. In general, they deteriorated rapidly and expired without active treatment. Surgical excision of the intracranial metastatic mass, followed by radiotherapy, can improve the life quality and prolong survival time.

Adult↗

PubMed2004

Protective effects of ghrelin on ischemia/reperfusion injury in the isolated rat heart.

Ghrelin, an endogenous ligand of the growth hormone secretagogue receptor, has been reported to have beneficial effects on cardiac function. The authors used the Langendorff model of ischemia/reperfusion (I/R) injury in isolated rat heart to determine whether ghrelin exerts direct cardioprotective effects. Also, the capacity of ghrelin to bind to sarcolemmal membrane fractions before and after ischemia and reperfusion was examined. Compared with vehicle administration, administration of ghrelin (100-10,000 pM) during the reperfusion period resulted in improvement in coronary flow, heart rate, left ventricular systolic pressure, and left ventricular end-diastolic pressure. Ghrelin also enhanced the rates of left ventricular contraction and relaxation after ischemia following reperfusion. Administration of ghrelin during reperfusion reduced myocardial release of lactate dehydrogenase and myoglobin, indicating protection against cardiomyocyte injury. In addition, ghrelin attenuated the depletion of myocardial ATP resulting from ischemia and reperfusion. A receptor-binding assay demonstrated that maximum binding capacity of ghrelin to sarcolemmal membranes was significantly increased after ischemia and was further increased after I/R. However, Scatchard analysis showed that the affinity of ghrelin for its receptor was not altered. The authors have concluded that administration of ghrelin during reperfusion protects against myocardial I/R injury. The cardioprotective effects are independent of growth hormone release and likely involve binding to cardiovascular receptors, a process that is upregulated during I/R.

Animals↗

PubMed2004

Racial differences in the impact of irritable bowel syndrome on health-related quality of life.

GOALS: To compare the impact of irritable bowel syndrome (IBS) on health related quality of life (HRQOI) for non-white and white IBS patients. BACKGROUND: There are no reported data evaluating the HRQOL of non-white persons with IBS. STUDY: SF-36 scores are compared between non-white IBS patients (n = 166), white IBS patients (n = 707), the general US population, and patients with selected chronic diseases. RESULTS: Of the n = 166 non-white IBS patients included for analysis, 66 (40%) described themselves as African-American, 56 (34%) as Hispanic, 25 (15%) as Asian-American, 2 (1%) as Native American and the remaining 17 (10%) as "other." Compared with white IBS patients, non-white IBS patients reported similar decrements in their HRQOL after controlling for age, gender, income and education level. On all 8 SF-36 scales, non-white IBS patients had significantly worse HRQOL compared with the general US population, (P < 0.001). Compared with GERD patients, non-white IBS patients scored significantly lower on all SF-36 scales (P < 0.001) except physical functioning. Similarly, non-white IBS patients had significantly worse HRQOL on selected SF-36 scales compared with diabetes mellitus and ESRD patients. Non-white IBS patients had significantly better emotional well-being than depressed patients, (P < 0.001). CONCLUSIONS: Non-white IBS patients experience impairment in vitality, role limitations-physical, and bodily pain. Yet overall, non-white IBS patients report similar HRQOL to white IBS patients. These data provide the first detailed evaluation of the impact of IBS on HRQOL in non-white IBS patients.

Adult↗

PubMed2004

Effects of taurine and homocysteine on calcium homeostasis and hydrogen peroxide and superoxide anions in rat myocardial mitochondria.

1. Taurine and homocysteine are metabolites of methionine. Hyperhomocysteinaemia is one of the risk factors for cardiovascular disease. Although taurine may be a cardiovascular cytoprotective substance, we hypothesized that it may antagonize the effects of homocysteine on myocardial mitochondrial function. 2. We studied the effects of taurine and homocysteine on [(45)Ca] uptake, Ca(2+)-ATPase activity and generation of hydrogen peroxide and superoxide anions in vitro in rat isolated myocardial mitochondria. 3. Results showed that the inhibition of mitochondrial [(45)Ca] uptake by homocysteine (0.1, 0.5 and 1.0 mmol/L) was concentration dependent. Taurine (5, 10 and 20 mmol/L) promoted [(45)Ca] uptake in a concentration-dependent manner, as well as concentration dependently reducing the homocysteine (0.5 mmol/L)-induced inhibition of mitochondrial [(45)Ca] uptake. 4. Homocysteine significantly inhibited mitochondrial Ca(2+)-ATPase activity, whereas taurine had a diphasic action on this activity. Taurine, at 5 and 10 mmol/L, increased Ca(2+)-ATPase activity (P < 0.01), but 20 mmol/L taurine inhibited Ca(2+)-ATPase activity (P < 0.05). Taurine attenuated the inhibitory effect of homocysteine on Ca(2+)-ATPase activity. 5. Homocysteine stimulated the generation of hydrogen peroxide and superoxide anions. Taurine had no effect on the generation of the anions, but inhibited their homocysteine-stimulated generation. 6. These results indicate that taurine and homocysteine have opposite effects in myocardial mitochondria with regard to [(45)Ca] uptake, Ca(2+)-ATPase activity and the generation of hydrogen peroxide and superoxide anions. Our results may show an important mechanism for the cardiovascular protective effects of taurine.

Animals↗

PubMed2004

Taurine antagonized oxidative stress injury induced by homocysteine in rat vascular smooth muscle cells.

AIM: To observe protective effects of taurine on reactive oxygen species generation induced by homocysteine in rat vascular smooth muscle cells (VSMC). METHODS: Rat VSMC was incubated with various concentrations of homocysteine and taurine. The lactate dehydrogenase (LDH) activity which released into culture medium was elevated as an indicator for VSMC injury. The reactive oxygen species (ROS)--hydrogen peroxide (H2O2) and superoxide anion (O2(-*)) were measured with luminol or lucigenin chemiluminescence method, and the mitochondria Mn-superoxide dismutase (Mn-SOD) and catalase (CAT) were also measured in treated VSMC. RESULTS: LDH leakage from cultured VSMC treated with homocysteine, was increased (P<0.01 vs control), and it was markedly inhibited when co-incubated with taurine (P<0.01). Homocysteine induced H2O2 generation from VSMC in a concentration dependent manner (P<0.01 vs control). However, taurine (5, 10, and 20 mmol/L) significantly antagonized 0.5 mmol/L homocysteine-induced H2O2 generation in VSMC in a concentration dependent manner (P<0.01 vs homocysteine alone group), although taurine itself did not alter the H2O2 generation in VSMC (P>0.05 vs control). In this study, the superoxide anion in VSMC was not detectable by chemiluminescence method. In addition, treatment of VSMC with taurine increased mitochondria Mn-SOD and CAT activity in a concentration dependent manner (P<0.05), but homocysteine decreased mitochondria Mn-SOD and CAT activity (P<0.01 vs control). In addition, co-administration of taurine markedly ameliorated homocysteine-induced inhibition of Mn-SOD and CAT activity in VSMC (P<0.01 vs homocysteine alone group). CONCLUSION: Taurine antagonized the effects of homocysteine on ROS generation and anti-oxidant enzyme activities in rat VSMC in vitro.

Animals↗

PubMed2004

Ghrelin protects myocardium from isoproterenol-induced injury in rats.

AIM: To investigate the cardiac protective effects of ghrelin in rat with myocardial injury induced by isoproterenol (ISO). METHODS: Rats were subcutaneously injected ISO 40 mg/kg/d with or without ghrelin 1 or 10 nmol/kg/d for 2 d. Hemodynamic parameters including mean arterial blood pressure and left ventricular pressure were measured at 12 h after the last injection with ISO and/or ghrelin. Plasma lactate dehydrogenase (LDH) activity, plasma and myocardial contents of malondialdehyde (MDA), and conjugated diene were measured. Plasma ghrelin and endothelin-1 levels were assayed using radioimmunoassay methods. Endothelin-1 and ghrelin mRNA were determined using RT-PCR. RESULTS: About 45 % (5/11) of rats after treatment with ISO alone died during experimental periods. However, no rats died after administration with ghrelin 10 nmol/kg/d (0/11, P<0.05). Ghrelin also obviously ameliorated the hemodynamic disturbance in rats induced by ISO. The plasma LDH activity, contents of myocardial and plasma MDA, and conjugated diene level in plasma in ISO+G10 nmol/kg/d group were decreased by 28 %, 34 %, 73 %, and 38 % compared with those of ISO group (all P<0.01) respectively. ISO-induced endothelin-1 mRNA over-expression was inhibited and endothelin-1 level in plasma were inhibited by ghrelin 1 and 10 nmol/kg/d. The ghrelin levels in plasma and ghrelin mRNA in myocardium were increased in the rats after injection of ISO. The plasma ghrelin level was further increased after ghrelin administration. CONCLUSION: Ghrelin has a protective effect against ISO-induced myocardial injury.

Animals↗

PubMed2003

Therapeutic effects of ghrelin on endotoxic shock in rats.

We investigated the effects of ghrelin in a rat endotoxic shock model, and also observed the direct role of endotoxin on ghrelin generation in gastric mucosa. About 55% (11/20) of rats treated with lipopolysaccharide (5 mg/kg i.v.) alone died within 24 h of endotoxin injection. However, administration of ghrelin either at the same time as lipopolysaccharide injection (early treatment) or 12 h after lipopolysaccharide injection (late treatment) significantly decreased the mortality rate and ameliorated the hypotension seen in rats with endotoxic shock. Early and late treatment with ghrelin increased markedly the plasma glucose concentration and decreased the plasma lactate concentration. Early treatment with ghrelin attenuated significantly the deficiency in myocardial ATP content, but late treatment with ghrelin had no effect on myocardial ATP content. The plasma ghrelin level was significantly increased in the rats with endotoxin shock, and it increased further after ghrelin administration. Exposure of rat gastric mucosa in vitro to lipopolysaccharide (1.0 to 100 microg/ml) triggered the release of ghrelin from mucosa tissue in a dose- and time-dependent manner, meaning that lipopolysaccharide stimulated directly gastric mucosa to synthesize and secrete ghrelin. The results suggest that ghrelin could have therapeutic value for endotoxic shock.

Adenosine Triphosphate↗

PubMed2003

Sex-related differences in IBS patients: central processing of visceral stimuli.

BACKGROUND & AIMS: Women have a higher prevalence of irritable bowel syndrome (IBS) and possible differences in response to treatment, suggesting sex-related differences in underlying pathophysiology. The aim of this study was to determine possible sex-related differences in brain responses to a visceral and a psychological stressor in IBS. METHODS: Regional cerebral blood flow measurements using H(2)(15)O positron emission tomography were compared across 23 female and 19 male nonconstipated patients with IBS during a visceral stimulus (moderate rectal inflation) and a psychological stimulus (anticipation of a visceral stimulus). RESULTS: In response to the visceral stimulus, women showed greater activation in the ventromedial prefrontal cortex, right anterior cingulate cortex, and left amygdala, whereas men showed greater activation of the right dorsolateral prefrontal cortex, insula, and dorsal pons/periaqueductal gray. Similar differences were observed during the anticipation condition. Men also reported higher arousal and lower fatigue. CONCLUSIONS: Male and female patients with IBS differ in activation of brain networks concerned with cognitive, autonomic, and antinociceptive responses to delivered and anticipated aversive visceral stimuli.

Adult↗

PubMed2003

Prevalence of irritable bowel syndrome among university students: the roles of worry, neuroticism, anxiety sensitivity and visceral anxiety.

OBJECTIVE: Relationships between presence of irritable bowel syndrome (IBS) and generalized anxiety disorder (GAD), chronic worry, neuroticism, anxiety sensitivity and anxiety about visceral sensations were examined among university students. METHODS: College student participants were administered self-report diagnostic measures of IBS and GAD, the Penn State Worry Questionnaire (PSWQ), the Neuroticism subscale of the Eysenck Personality Questionnaire, the Anxiety Sensitivity Index (ASI) and five additional items designed to measure visceral anxiety. RESULTS: The prevalence of IBS and its associated characteristics among students were similar to previous community survey studies, with the exception of lower symptom severity in the university sample. IBS was associated with a higher frequency of GAD and greater worry, neuroticism, anxiety sensitivity and visceral anxiety. Logistic regression analyses further showed that the measure of anxiety specific to visceral sensations was the strongest predictor of IBS diagnostic status. CONCLUSIONS: While various aspects of anxiety appear related to IBS, specific anxiety about visceral sensations appears to be the most significant factor. Implications of the associations between anxiety-related variables, particularly anxiety about visceral sensations, are discussed.

Abdominal Pain↗

PubMed2003

Irritable bowel syndrome patients show enhanced modulation of visceral perception by auditory stress.

OBJECTIVES: Symptoms in irritable bowel syndrome (IBS) patients are sensitive to psychological stressors. These effects may operate through an enhanced responsiveness of the emotional motor system, a network of brain circuits that modulate arousal, viscerosomatic perception, and autonomic responses associated with emotional responses, including anxiety and anger. The aim of this study was to test the primary hypothesis that IBS patients show altered perceptual responses to rectal balloon distention during experimentally induced psychological stress compared with healthy control subjects. METHODS: A total of 15 IBS patients (nine women and six men) and 14 healthy controls (seven women and seven men) were studied during two laboratory sessions: 1) a mild stress condition (dichotomous listening to two conflicting types of music), and 2) a control condition (relaxing nature sounds). The stress and relaxation auditory stimuli were delivered over a 10-min listening period preceding rectal distentions and during the rectal distentions but not during the distention rating process. Ratings of intensity and unpleasantness of the visceral sensations, subjective emotional responses, heart rate, and neuroendocrine measures (norepinephrine, cortisol, adrenocorticotropic hormone [ACTH], and prolactin) were obtained during the study. RESULTS: IBS patients, but not healthy controls, rated the 45-mm Hg visceral stimulus significantly higher in terms of intensity and unpleasantness during the stress condition compared with the relaxation condition. IBS patients also reported higher ratings of stress, anger, and anxiety during the stress compared with the relaxing condition, whereas controls had smaller and nonsignificant subjective responses. Heart rate measurements, but not other neuroendocrine stress measures, were increased under the stress condition in both groups. CONCLUSION: These findings confirm the hypothesis of altered stress-induced modulation of visceral perception in IBS patients.

Acoustic Stimulation↗