Gender differences in irritable bowel syndrome

Visceral pain: gender differences in response to experimental and clinical pain

Gender differences in response to visceral pain have important implications for experimental studies and when evaluating clinical pain. Few studies have in details explored specific gender differences in response to experimental stimulation of selected visceral organs or specific visceral diseases. Lower pain threshold to e.g. oesophageal distension has however been shown in females. The effect of female sex hormones on visceral function and pain is studied in greater details in both experimental and clinical studies. Pronounced differences in pain sensitivity are found across the menstrual phases. This may also interact with pharmacological interventions. For clinicians assessing the pain level of female patients in the reproductive age group should take into consideration the physiological and clinical effects of the menstrual cycle and the somatic segmental sites related to the uterus and cervix when clinically evaluating the pain and assessing for disease activity.

Review article: epidemiology and quality of life in functional gastrointestinal disorders

The epidemiology and health-related quality of life associated with functional gastrointestinal disorders are reviewed, with particular emphasis on irritable bowel syndrome and functional dyspepsia. The literature supports the significant world-wide prevalence of functional gastrointestinal disorders, including irritable bowel syndrome (IBS), functional dyspepsia and chronic constipation. An increased female prevalence has been demonstrated in most studies in patients with IBS and chronic constipation, but not functional dyspepsia. The female to male ratio appears to be greater in the health care-seeking population than in community populations. However, some differences in the reported general prevalence and gender-related prevalence of functional gastrointestinal disorders may be due to cultural factors and study methodology. A significant health care burden is associated with IBS, with increased out-patient services, abdominal and pelvic surgeries, and gastrointestinal- and non-gastrointestinal-related physician visits and health care costs. Health-related quality of life is impacted significantly in patients with functional gastrointestinal disorders, such as functional dyspepsia and IBS, compared with the general healthy population, as well as patients with other chronic medical conditions, such as gastro-oesophageal reflux disease and asthma. Impaired health-related quality of life has been demonstrated, in particular, in patients with moderate to severe disease seen in referral settings. The health-related quality of life appears to improve in treatment responders, or correlates with symptom improvement, with at least some treatment modalities studied in functional gastrointestinal disorders, but further studies are needed. Predictors of health-related quality of life in patients with functional gastrointestinal disorders include psychosocial factors, such as early adverse life events, and symptoms related to visceral perception, e.g. pain and chronic stress. The presence of extra-intestinal symptoms appears to have a major if not greater impact on health care visits, excess health care costs and health-related quality of life in patients with functional gastrointestinal disorders.

Irritable bowel syndrome in France: a common, debilitating and costly disorder

OBJECTIVE

This epidemiological investigation aims to measure the prevalence of irritable bowel syndrome (IBS) in the general population using the Rome II criteria and to evaluate the medical management including treatments and the impact of IBS on patient life.

METHODS

A nationally representative sample of 20,000 French subjects, aged 18 years and over, were interviewed by SOFRES (French Public Opinion Poll Institute) in May 2001. In a second phase (June/July 2001), a 48-question self-administered questionnaire was given to the subjects who have been selected during the first phase as suffering from IBS (Rome II criteria).

RESULTS

The prevalence of IBS was 4.7% (confidence interval, 4.36-5.04% with 5% risk) with a predominance in women (5.7% versus 3.7%, P < 0.01). The abdominal pain was often longstanding (> 5 years, 50%), intense (43%) and nocturnal (35%). During the most recent painful episode the levels of associated transit problems were almost equally divided between diarrhoea (36%), constipation (29%) and alternate episodes of both (31%). Apart from pain, bloating was given as the most frequent (73%) and most troublesome (24%) symptom. Since the onset, 80% of subjects with IBS had consulted a doctor (90% consulted a general physician, 57% a gastroenterologist, 50% both) and of these, 80% consulted within the previous 12 months. Sixty-seven per cent of subjects underwent additional investigations since the start of their illness (average of 3.4 examinations per patient examined: colonoscopy, 34.1%; laboratory tests, 34%; and abdominal ultrasound, 27.7%). Over the previous 12 months, 8% of the subjects had been admitted to hospital (average length of stay, 6.6 days), 11% of employed subjects had to take time off, 93% of subjects had taken prescribed medication (87%), but 43% of people thought it was ineffective. The effect on daily life was considerable (score, 6.2/10; close to the score for flu, 7/10). Two-thirds of the individuals changed their diet; 54% said it affected their social life and 29% their professional life. Seventy-four per cent of patients trusted their doctor, with a satisfaction index of 63%, but 45% of patients would like to have more information on IBS.

CONCLUSION

This study confirmed that the Rome II criteria detected IBS with a prevalence of 4.7%. The recruited subjects had severe symptoms (frequency, intensity and duration) that had a considerable effect on their daily life. The high level of referrals and initial consultations in all categories and the patient's attitudes towards the illness and its treatment emphasize the relative ineffectiveness of care for patients suffering from IBS.

Gender and irritable bowel syndrome: the male connection

BACKGROUND/GOALS

Irritable bowel syndrome is more common in women; and this is generally considered to be caused by increased susceptibility. However, the opposite possibility that being male might actually protect from the disorder in some way, has largely been ignored. We have noticed that men with IBS seem to display less masculine and more feminine qualities and it was the purpose of this study to confirm or refute this clinical observation.

STUDY

Seventy consecutive male, secondary care outpatients fulfilling the Rome 1 criteria for irritable bowel syndrome and 70 controls completed a questionnaire to determine male and female-trait scores. In addition, all subjects were assessed using the hospital anxiety depression inventory.

RESULTS

A highly significant reduction in male-trait scores was observed in the irritable bowel syndrome patients compared with controls (-10.5[-15.7,-5.2] P < 0.001). There were no differences between the groups with respect to female-trait scores. The prevalence of homosexuality was no different between patients and controls.

CONCLUSION

Men with irritable bowel syndrome exhibit less male characteristics and it remains to be determined whether this is cause or effect. Whatever the explanation, this study adds another dimension to the role of gender in functional gastrointestinal disorders.

The effects of withdrawing tegaserod treatment in comparison with continuous treatment in irritable bowel syndrome patients with abdominal pain/discomfort, bloating and constipation: a clinical study

BACKGROUND

The post-withdrawal characteristics of tegaserod treatment in patients with irritable bowel syndrome with constipation remain undefined.

AIM

To evaluate the effects of continuous tegaserod treatment, versus intermittent or withdrawal of treatment in patients with irritable bowel syndrome with constipation.

METHODS

In a randomized, open-label trial, all patients initially received tegaserod 6 mg b.d. Responders were randomized to continue or withdraw from treatment for 8 weeks and symptom recurrence was assessed. Tegaserod was re-introduced in withdrawal patients who experienced symptom recurrence, allowing an assessment of intermittent treatment. Two separate analyses assessed the effects of intermittent and withdrawal of treatment on symptom recurrence.

RESULTS

Five hundred irritable bowel syndrome with constipation patients initially received tegaserod; 410 completed treatment. Time to symptom recurrence was shorter in withdrawal patients than those maintained on tegaserod. Significantly more patients maintained on tegaserod had not experienced symptom recurrence by week 8, compared with intermittent (86.5% vs. 58.1%, respectively) or withdrawal of treatment (69.2% vs. 11.3%, respectively) (P < 0.0001 for both). Significant treatment effects were observed for bloating (P < 0.01) and abdominal pain/discomfort (P < 0.02). Most adverse events were mild to moderate.

CONCLUSIONS

Irritable bowel syndrome with constipation patients who receive continuous or intermittent tegaserod are less likely to experience symptom recurrence than patients withdrawn from treatment.

New pathophysiological mechanisms in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional, multifactorial disease characterized by abdominal pain and erratic bowel habit. Changes in gastrointestinal motor function, enhanced perception of stimuli arising from the gut wall and psychosocial factors are thought to be major contributors for symptom generation. In recent years, several additional factors have been identified and postulated to interact with these classical mechanisms. Reduced ability to expel intestinal gas with consequent gas trapping and bowel distension may contribute to abdominal discomfort/pain and bloating. Abnormal activation of certain brain regions following painful stimulation of the rectum suggests altered processing of afferent signals. An acute gastrointestinal infection is now a recognized aetiological factor for symptom development in a subset of IBS patients (i.e. post-infectious IBS), who are probably unable to down-regulate the initial inflammatory stimulus efficiently. Furthermore, low-grade inflammatory infiltration and activation of mast cells in proximity to nerves in the colonic mucosa may also participate in the frequency and severity of perceived abdominal pain in post-infectious and non-specific IBS. Initial evidence suggests the existence of changes in gut microflora, serotonin metabolism and a genetic contribution in IBS pathophysiology. These novel mechanisms may aid a better understanding of the complex pathophysiology of IBS and to develop new therapies.

Management of irritable bowel syndrome

Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders. The prevalence rate is 10-20% and women have a higher prevalence. IBS adversely affects quality of life and is associated with health care use and costs. IBS comprises a group of functional bowel disorders in which abdominal discomfort or pain is associated with defecation or a change in bowel habit, and with features of disordered defecation. The consensus definition and criteria for IBS have been formalized in the "Rome II criteria". Food, psychiatric disorders, and gastroenteritis are risk factors for developing IBS. The mechanism in IBS involves biopsychosocial disorders; psychosocial factors, altered motility, and heightened sensory function. Brain-gut interaction is the most important in understanding the pathophysiology of IBS. Effective management requires an effective physician-patient relationship. Dietary treatment, lifestyle therapy, behavioral therapy, and pharmacologic therapy play a major role in treating IBS. Calcium polycarbophil can benefit IBS patients with constipation or alternating diarrhea and constipation.

Irritable bowel syndrome and abdominoplasty

Irritable bowel syndrome is a chronic disease involving pain or discomfort relieved by defecation and associated with a change in frequency or consistency of the stools. The effect of abdominoplasty on patients with irritable bowel syndrome has not been elucidated, so advising patients with irritable bowel syndrome about the effects of surgery on their disease was difficult. One hundred female patients from a pool of 120 patients responded to a questionnaire relating to abdominoplasty surgery. Follow-up ranged from 6 months to 2 years. Patients completed questionnaires formulated on the basis of Rome II Diagnostic Criteria. Of the 100 patients, nine had true irritable bowel syndrome, nine had moderate symptoms and were receiving medication (not true irritable bowel syndrome), 16 had mild symptoms on occasional medication, and 66 had no symptoms of irritable bowel syndrome before surgery. Of the true irritable bowel syndrome patients, all had symptomatic improvement with decreased medication, eight of the nine patients with moderate symptoms improved markedly, and five of the 16 patients with mild symptoms improved significantly. No patient had any initiation or deterioration of symptoms. It is thus concluded that the symptoms of irritable bowel syndrome are certainly not worsened, in the short term, by surgery, and may be alleviated or improved in most significant cases.

Activated mast cells in proximity to colonic nerves correlate with abdominal pain in irritable bowel syndrome

BACKGROUND & AIMS

The mechanisms underlying abdominal pain perception in irritable bowel syndrome (IBS) are poorly understood. Intestinal mast cell infiltration may perturb nerve function leading to symptom perception. We assessed colonic mast cell infiltration, mediator release, and spatial interactions with mucosal innervation and their correlation with abdominal pain in IBS patients.

METHODS

IBS patients were diagnosed according to Rome II criteria and abdominal pain quantified according to a validated questionnaire. Colonic mucosal mast cells were identified immunohistochemically and quantified with a computer-assisted counting method. Mast cell tryptase and histamine release were analyzed immunoenzymatically. Intestinal nerve to mast cell distance was assessed with electron microscopy.

RESULTS

Thirty-four out of 44 IBS patients (77%) showed an increased area of mucosa occupied by mast cells as compared with controls (9.2% +/- 2.5% vs. 3.3 +/- 0.8%, respectively; P < 0.001). There was a 150% increase in the number of degranulating mast cells (4.76 +/- 3.18/field vs. 2.42 +/- 2.26/field, respectively; P = 0.026). Mucosal content of tryptase was increased in IBS and mast cells spontaneously released more tryptase (3.22 +/- 3.48 pmol/min/mg vs. 0.87 +/- 0.65 pmol/min/mg, respectively; P = 0.015) and histamine (339.7 +/- 59.0 ng/g vs. 169.3 +/- 130.6 ng/g, respectively; P = 0.015). Mast cells located within 5 microm of nerve fibers were 7.14 +/- 3.87/field vs. 2.27 +/- 1.63/field in IBS vs. controls (P < 0.001). Only mast cells in close proximity to nerves were significantly correlated with severity and frequency of abdominal pain/discomfort (P < 0.001 and P = 0.003, respectively).

CONCLUSIONS

Colonic mast cell infiltration and mediator release in proximity to mucosal innervation may contribute to abdominal pain perception in IBS patients.

Stomach-brain communication by vagal afferents in response to luminal acid backdiffusion, gastrin, and gastric acid secretion

Vagal afferents play a role in gut-brain signaling of physiological and pathological stimuli. Here, we investigated how backdiffusion of luminal HCl or NH(4)OH and pentagastrin-stimulated acid secretion interact in the communication between rat stomach and brain stem. Rats were pretreated intraperitoneally with vehicle or appropriate doses of cimetidine, omeprazole, pentagastrin, dexloxiglumide (CCK(1) receptor antagonist), and itriglumide (CCK(2) receptor antagonist) before intragastric administration of saline or backdiffusing concentrations of HCl or NH(4)OH. Two hours later, neuronal activation in the nucleus of the solitary tract (NTS) and area postrema was visualized by c-Fos immunohistochemistry. Exposure of the rat gastric mucosa to HCl (0.15-0.5 M) or NH(4)OH (0.1-0.3 M) led to a concentration-dependent expression of c-Fos in the NTS, which was not related to gender, gastric mucosal injury, or gastropyloric motor alterations. The c-Fos response to HCl was diminished by cimetidine and omeprazole, enhanced by pentagastrin, and left unchanged by dexloxiglumide and itriglumide. Pentagastrin alone caused an omeprazole-resistant expression of c-fos, which in the NTS was attenuated by itriglumide and prevented by dexloxiglumide but in the area postrema was reduced by dexloxiglumide and abolished by itriglumide. We conclude that vagal afferents transmit physiological stimuli (gastrin) and pathological events (backdiffusion of luminal HCl or NH(4)OH) from the stomach to the brain stem. These communication modalities interact because, firstly, acid secretion enhances afferent signaling of gastric acid backdiffusion and, secondly, gastrin activates NTS neurons through stimulation of CCK(1) receptors on vagal afferents and of CCK(2) receptors on area postrema neurons projecting to the NTS.

Irritable bowel syndrome in women: a common health problem

Irritable bowel syndrome is a common but complex problem that disproportionately affects women. Nurses are ideally situated to provide accurate information regarding the disorder and to provide symptom management. Currently, the diagnosis is based on the presence of abdominal pain and alterations in bowel habits. A multicomponent approach beginning with education and reassurance is more likely to be effective than one focused on a predominant symptoms (eg., constipation) alone. Building a therapeutic relationship with the patient over time will likely enhance the effectiveness of the prescribed therapy. Treatment paradigms that include new drugs that affect more than one symptom of IBS, along with nondrug therapies (eg, relaxation and cognitive behavioral strategies), will likely hold the greatest promise for management.

Genome-wide linkage survey for genetic loci that influence the development of depressive disorders in families with recurrent, early-onset, major depression

In this report, we describe the results of the first genome-wide linkage survey for genetic loci that influence the development of unipolar Mood Disorders in 81 families identified by individuals with Recurrent, Early-Onset, Major Depressive Disorder (RE-MDD). Model-free linkage analysis was performed using genotypes for 392 highly informative polymorphisms with an average spacing of 9 cM. The highest maximum LOD score observed, 8.19 (genome-wide adjusted P << 0.0001), occurred for Recurrent Major Depressive Disorder (R-MDD) at D2S2321 (205 cM), located 121 kb proximal to CREB1. Nineteen chromosomal regions contained linkage peaks that reached genome-wide statistical significance (genome-wide adjusted P < 0.05) and ten of these were "highly significant" (adjusted P < 0.001). Six of the 19 linkage peaks were revealed only when the analysis included covariates to control for the effects of sex and linkage to CREB1. Sex-specific susceptibility loci were common and preferentially affected the vulnerability of women to developing unipolar Mood Disorders. Five loci revealed evidence of interaction with the CREB1 locus in determining susceptibility (epistasis). A systematic candidate gene analysis is presented and potential overlaps of the linkage regions for unipolar Mood Disorders with those reported for other psychiatric disorders are discussed. The findings suggest that genes whose products participate in cellular signaling pathways that converge on CREB, as well as the target genes whose expression they regulate, may also harbor alleles that affect the development of Mood Disorders and related conditions.

Perceptions of health-related quality of life of men and women living with coeliac disease

Women with long-standing coeliac disease express poorer health-related quality of life (HRQoL) than men do for unclear reasons. This led us to explore differences in their understanding of HRQoL using a phenomenographic approach. We interviewed 10 coeliac subjects (mean age 57 years, range 35-73) who had been on a gluten-free diet for 10 years and had scored either high or low in the Short Form 36 Health Survey (SF-36) General Health and Vitality scales. Three dimensions were revealed that pertained to their perception of HRQoL: bodily sensations, social consequences and coping strategies. Within these, the women experienced more bowel symptoms than men did, despite keeping to a strict diet. This item was the only one predicting the SF-36 scores. The women also described more distress caused by the restrictions in daily life, closely related to their controlling of food contents. The coeliac men took advantage of using a problem-oriented coping approach while the women seeking an emotionally oriented strategy showed less satisfaction with the outcome. We conclude that the intriguing difference in HRQoL between coeliac men and women may have some of its origin in the way living with the disorder is conceptualized and coped with. The results imply that in the management of coeliac patients, gender-related aspects need to be taken into account to improve treatment outcome.

Tegaserod maleate in the treatment of irritable bowel syndrome: a clinical review

BACKGROUND

Approved in July 2002, tegaserod maleate is a partial 5-hydroxytryptamine 4-receptor agonist used to improve symptoms of constipation-predominant irritable bowel syndrome (IBS). The physiologic actions of tegaserod relate to its ability to stimulate gastric and intestinal motility.

OBJECTIVE

This article reviews available data on the pharmacokinetic and pharmacodynamic properties and clinical efficacy of tegaserod.

METHODS

Searches of MEDLINE and PubMed from 1966 to the present were conducted using the search terms tegaserod, tegaserod maleate, irritable bowel syndrome, and Rome criteria. Abstracts presented at national meetings between 1997 and 2002 were reviewed and included if perceived to be reliable and relevant.

RESULTS

In clinical trials, tegaserod was associated with significantly better scores on the subject's global assessment of relief compared with placebo (P < 0.05). The absolute efficacy of tegaserod compared with placebo varied between trials and averaged 10% to 12%. Tegaserod had a good safety profile; diarrhea was the only adverse effect that occurred more often in tegaserod recipients than in placebo recipients. No electrocardiographic changes were observed at therapeutic concentrations of tegaserod. Long-term (1-year) treatment with tegaserod appeared to be well tolerated. The recommended dosage for patients aged >18 years with constipation-predominant IBS is 6 mg PO BID before meals for 4 to 6 weeks, with an additional 4 to 6 weeks of treatment if initial therapy is partially effective.

CONCLUSIONS

The addition of tegaserod to the arsenal of moderately effective medication currently used in the treatment of IBS may be helpful in patients with constipation-predominant IBS. Continuous postmarketing surveillance and reporting of adverse reactions are essential to further characterize the safety profile of this new agent.

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.