Search PubMed⌕ Search

Biomedical subjects

K W Heaton

Publications and source records attributed to K W Heaton.

At least 19 recordsLinked to original sources
PubMed2001

Ursodeoxycholic acid alone or with chenodeoxycholic acid for dissolution of cholesterol gallstones: a randomized multicentre trial. The British-Italian Gallstone Study group.

BACKGROUND: Combination therapy using ursodeoxycholic acid plus chenodeoxycholic acid has been advocated for dissolution of cholesterol gallstones because the two bile acids have complementary effects on biliary lipid metabolism and cholesterol solubilization. AIM: To compare the clinical efficacy of combination therapy with ursodeoxycholic acid monotherapy. PATIENTS AND METHODS: A total of 154 symptomatic patients with radiolucent stones (< or = 15 mm) in functioning gallbladders were enrolled from six centres in England and Italy. They were randomized to either a combination of chenodeoxycholic acid plus ursodeoxycholic acid (5 mg.day/kg each) or to ursodeoxycholic acid alone (10 mg.day/kg). Dissolution was assessed by 6-monthly oral cholecystography and ultrasonography for up to 24 months. RESULTS: Both regimens reduced the frequency of biliary pain and there was no significant difference between them in terms of side-effects or dropout rate. Complete gallstone dissolution on an intention-to-treat basis was similar at all time intervals. At 24 months this was 28% with ursodeoxycholic acid alone and 30% with combination therapy. The mean dissolution rates at 6 and 12 months were 47% and 59% with ursodeoxycholic acid, and 44% and 59% with combination therapy, respectively. CONCLUSION: There is no substantial difference in the efficacy of combined ursodeoxycholic acid and chenodeoxycholic acid and that of ursodeoxycholic acid alone in terms of gallstone dissolution rate, complete gallstone dissolution, or relief of biliary pain.

Adult↗
PubMed2000

Review article: epidemiology of gall-bladder disease--role of intestinal transit.

Recent epidemiological studies have suggested that hyperinsulinaemia may be a central factor in the pathogenesis of cholesterol gallstones, explaining a probable link with physical inactivity as well as abdominal adiposity. There is also increasing evidence for the hypothesis that enrichment of bile with DCA. 'the colonic bile acid', leads to enrichment of bile with cholesterol. Biliary DCA can be raised and lowered by slowing down and speeding up colonic transit, respectively. Slow transit is characteristic of non-obese British women with gallstones and of non-obese peasants in a gallstone-prone mountain community. High biliary DCA predicts recurrence of gallstones and so does laxative usage, a pointer to constipation and therefore to slow transit. In some studies, at least, a high fibre intake is protective against gallstones. Much else besides fibre influences colonic function. Future studies of gallstone aetiology should include measurements of colonic function. Measures that speed up colonic transit should be tested for their ability to prevent gallstone formation in high-risk individuals.

Adult↗
PubMed2000

Risk factors for the development of gallstone recurrence following medical dissolution. The British-Italian Gallstone Study Group.

OBJECTIVE: To assess risk factors for gallstone recurrence following non-surgical treatment. DESIGN: A prospective follow-up of a multicentre cohort of post-dissolution gallstone patients. SETTING: Six gastroenterology units in the UK and Italy. PARTICIPANTS: One hundred and sixty-three patients with confirmed gallstone dissolution following non-surgical therapy (bile acids or lithotripsy plus bile acids), followed up by ultrasound scan and clinical assessment at 6-monthly intervals for up to 6 years (median, 25 months; range, 6-70 months). OUTCOME MEASURES: Subject-related variables (sex, age, height, weight, body mass index), gallstone-related variables (number, diameter, presence of symptoms, months to complete stone clearance), treatment modalities (bile acid therapy, extracorporeal shock wave lithotripsy) and follow-up related variables (weight change, use of non-steroidal anti-inflammatory agents, statins, pregnancies and/or use of oestrogens) were assessed by univariate and multivariate analysis as putative risk factors for gallstone recurrence. RESULTS: Forty-five gallstone recurrences were observed during the follow-up period. Multiple primary gallstones and length of time to achieve gallstone dissolution were the only variables associated with a significant increase in the recurrence rate. Appearance of biliary sludge during follow-up was also significantly related to development of gallstone recurrence. Use of statins or non-steroidal anti-inflammatory agents did not confer protection against recurrence. CONCLUSIONS: Patients with primary single stones are the best candidates for non-surgical treatment of gallstones, because of a low risk of gallstone recurrence. The positive association of recurrence with biliary sludge formation and time to dissolution of primary stones may provide indirect confirmation for the role of impaired gallbladder motility in the pathogenesis of this condition.

Adolescent↗
PubMed2000

Irritable bowel syndrome in general practice: prevalence, characteristics, and referral.

BACKGROUND AND AIMS: Little is known about the prevalence, symptoms, diagnosis, attitude, and referral to specialists of patients with irritable bowel syndrome (IBS) in general practice. This study aimed to determine these characteristics. METHODS: 3111 patients attending 36 general practitioners (GPs) at six varied locations in and near Bristol, UK, were screened to identify those with a gastrointestinal problem. These patients (n=255) and their doctors were given questionnaires. Six months later the case notes were examined to reach criteria based diagnoses of functional bowel disorders. RESULTS: Of 255 patients with a gastrointestinal complaint, 30% were judged to have IBS and 14% other functional disorders. Compared with 100 patients with an "organic" diagnoses, those with IBS were more often women and more often judged by their GP to be polysymptomatic and to have unexplained symptoms. The majority of patients with IBS (58%) were diagnosed as such by the GP; 22% had other functional diagnoses. Conversely, among 54 patients diagnosed as having IBS by the GPs, the criteria based diagnosis was indeed functional in 91%; only one patient had organic disease (proctitis). More patients with IBS than those with organic disease feared cancer. In most some fear remained after the visit to the doctor. On logistic regression analysis, predictors of referral to a specialist (29% referred) were denial of a role for stress, multiple tests, and frequent bowel movements. CONCLUSIONS: Half the patients with gut complaints seen by GPs have functional disorders. These are usually recognised, and few patients are referred. In IBS, cancer fears often remain, suggesting unconfident diagnosis or inadequate explanation.

Adolescent↗
PubMed1999

Roughage revisited: the effect on intestinal function of inert plastic particles of different sizes and shape.

The mechanisms by which dietary fiber exerts its laxative action are not fully understood. Finely grinding wheat bran reduces its effect. Inert plastic particles are equipotent to bran if they consist of flakes or sliced tubing. It is not known whether altering the size or shape of inert particles alters their effect on intestinal function. In a randomized crossover study, 18 volunteers swallowed 24 g/day of plastic as branlike flakes or as small granules for 10-12 days with a two-week washout period between interventions. Whole-gut transit time (WGTT), orocecal transit time (OCTT), defecation frequency, stool form, stool water content, stool pH, and dietary intake were assessed. The plastic flakes caused a 24% (P < 0.001) reduction in WGTT and a 19% (P = 0.002) fall in OCTT. Resultant and appropriate changes in stool form, interdefecatory intervals (IDI), and stool weight were seen. The small granules did not cause any significant change in WGTT or OCTT, although IDI did decrease and stool output and stool form score increased. The stimulant effect of solid particles in the intestinal lumen upon transit time is influenced by the morphology of the particles.

Adult↗
PubMed1999

The metabolic consequences of slow colonic transit.

Intestinal transit has a substantial influence on the enterohepatic circulation of bile acids and steroid hormones, on colonic pH, and on short chain fatty acid concentrations in the distal colon. Slow transit is likely to favor disease processes that are related to over-efficient enterohepatic recirculation and to lack of short chain fatty acid in the distal colon. These include gallstones, large bowel cancer, and possibly breast cancer. The best-documented influence of slow colonic transit is on bile acid metabolism. Slowing colonic transit increases deoxycholate and raises cholesterol saturation of bile, making gallstone formation more likely. In this review, we also examine the evidence that slow colonic transit may be important in the etiology of large bowel and breast cancer. There is a lack of data pertaining to the relationship between colonic transit and diseases such as colon and breast cancer. Should slow colonic transit prove to be a significant factor in the etiology of such diseases, then the health of the population might benefit from dietary and lifestyle changes that speed up intestinal transit.

Bile Acids and Salts↗
PubMed1999

Functional bowel disorders and functional abdominal pain.

The Rome diagnostic criteria for the functional bowel disorders and functional abdominal pain are used widely in research and practice. A committee consensus approach, including criticism from multinational expert reviewers, was used to revise the diagnostic criteria and update diagnosis and treatment recommendations, based on research results. The terminology was clarified and the diagnostic criteria and management recommendations were revised. A functional bowel disorder (FBD) is diagnosed by characteristic symptoms for at least 12 weeks during the preceding 12 months in the absence of a structural or biochemical explanation. The irritable bowel syndrome, functional abdominal bloating, functional constipation, and functional diarrhea are distinguished by symptom-based diagnostic criteria. Unspecified FBD lacks criteria for the other FBDs. Diagnostic testing is individualized, depending on patient age, primary symptom characteristics, and other clinical and laboratory features. Functional abdominal pain (FAP) is defined as either the FAP syndrome, which requires at least six months of pain with poor relation to gut function and loss of daily activities, or unspecified FAP, which lacks criteria for the FAP syndrome. An organic cause for the pain must be excluded, but aspects of the patient's pain behavior are of primary importance. Treatment of the FBDs relies upon confident diagnosis, explanation, and reassurance. Diet alteration, drug treatment, and psychotherapy may be beneficial, depending on the symptoms and psychological features.

Abdominal Pain↗
PubMed1999

Effect of cholecystectomy on bowel function: a prospective, controlled study.

BACKGROUND: Published estimates of the prevalence of postcholecystectomy diarrhoea derive from retrospective or uncontrolled data. They ignore functional bowel syndromes and possible changes in diet and drug use. AIMS: To determine prospectively whether and how often cholecystectomy leads to changes in bowel function and bowel symptoms, especially to liquid stools, over and above any non-specific effect of laparoscopic surgery. SUBJECTS PATIENTS: 106 adults undergoing laparoscopic cholecystectomy (85 women, 21 men). CONTROLS: 37 women undergoing laparoscopic sterilisation. METHODS: Before and 2-6 months after surgery patients were administered questionnaires about bowel frequency, bowel symptoms, diet, and drugs, and kept records of five consecutive defecations with assessment of stool form or appearance on a seven point scale. RESULTS: In cholecystectomised women, stated bowel frequency increased, on average by one movement a week, and fewer subjects felt that they became constipated. However, records showed no consistent change in bowel frequency, stool form, or defecatory symptoms. Six women reported diarrhoea after the operation but in only one was it clearly new and in her it was mild. Change in dietary fibre intake did not associate with change in bowel function but stopping constipating drugs did in a minority. In women being sterilised there was no consistent change in bowel function. In men having cholecystectomy no consistent changes were observed. CONCLUSIONS: In women, cholecystectomy leads to the perception of less constipation and slightly more frequent defecations but short term recordings show no consistent change in bowel function. Clinical diarrhoea develops rarely and is not severe.

Adult↗
PubMed1998

Intestinal absorption of oestrogen: the effect of altering transit-time.

OBJECTIVE: The mechanism by which a high fibre diet may reduce serum oestrogens is unknown. We hypothesized that time is a rate-limiting factor in oestrogen absorption from the colon so that changes in colonic transit-rate affect the proportion of oestrogen that is deconjugated and/or absorbed. AIM: To determine if alteration of intestinal transit rate would influence the absorption of an oral dose of oestradiol glucuronide. PARTICIPANTS: Twenty healthy postmenopausal women recruited by advertisement. SETTING: Department of Medicine, Bristol Royal Infirmary. METHODS: Volunteers consumed, in turn, wheat bran, senna, loperamide and bran shaped plastic flakes, each for 10 days with a minimum 2 week washout period between study periods, dietary intake being unchanged. Before and in the last 4 days of each intervention whole-gut transit-time, defecation frequency, stool form, stool beta-glucuronidase activity, stool pH and the absorption of a 1.5 mg dose of oestradiol glucuronide were measured. RESULTS: Wheat bran, senna and plastic flakes led to the intended reduction in whole-gut transit-time, increase in defecatory frequency and increase in stool form score. Loperamide caused the opposite effect. The length of time the absorbed oestrogen was detectable in the serum fell with wheat bran and senna, although this was only significant for oestradiol. Oestrone, but not oestradiol, was detectable for a longer time with loperamide. Plastic flakes had no effect on either oestrogen. Areas under the curve did not change significantly but tended to fall with the three transit-accelerating agents and to rise with loperamide. CONCLUSION: Our data indicate there is likely to be an effect of intestinal transit on the absorption of oestrogens but more refined techniques are needed to characterize this properly.

Dietary Fiber↗
PubMed1997

Lower serum oestrogen concentrations associated with faster intestinal transit.

Increased fibre intake has been shown to reduce serum oestrogen concentrations. We hypothesized that fibre exerts this effect by decreasing the time available for reabsorption of oestrogens in the colon. We tested this in volunteers by measuring changes in serum oestrogen levels in response to manipulation of intestinal transit times with senna and loperamide, then comparing the results with changes caused by wheat bran. Forty healthy premenopausal volunteers were placed at random into one of three groups. The first group took senna for two menstrual cycles then, after a washout period, took wheat bran, again for two menstrual cycles. The second group did the reverse. The third group took loperamide for two menstrual cycles. At the beginning and end of each intervention a 4-day dietary record was kept and whole-gut transit time was measured; stools were taken for measurement of pH and beta-glucuronidase activity and blood for measurement of oestrone and oestradiol and their non-protein-bound fractions and of oestrone sulphate. Senna and loperamide caused the intended alterations in intestinal transit, whereas on wheat bran supplements there was a trend towards faster transit. Serum oestrone sulphate fell with wheat bran (mean intake 19.8 g day(-1)) and with senna; total- and non-protein-bound oestrone fell with senna. No significant changes in serum oestrogens were seen with loperamide. No significant changes were seen in faecal beta-glucuronidase activity. Stool pH changed only with senna, in which case it fell. In conclusion, speeding up intestinal transit can lower serum oestrogen concentrations.

Adult↗
PubMed1997

Gallstones in a community free of obesity but prone to slow intestinal transit.

OBJECTIVES: To verify anecdotal reports that gallstones were frequent in a remote community where obesity is rare and to look for possible explanations of their occurrence, including slow intestinal transit. DESIGN: Population survey of gallbladder status and stool form. SETTING: Two villages in Ladakh, a mountainous region of northern India; for comparison, a stratified random sample from general practitioners' lists in East Bristol. SUBJECTS: Women aged 25-59 years, 437 in Ladakh and 974 in Bristol. MAIN OUTCOME MEASURES: Presence of gallstones on ultrasonography and response to questionnaires about parity, the intake of dried legume seeds (pulses) and bowel function including the form or appearance of the stools on a seven-point, transit-sensitive scale. Weight, height and waist circumference were also recorded. RESULTS: Gallstone disease was at least as frequent in Ladakh as in Bristol although Ladakhi women were uniformly slim and their weight, waist size and body mass index failed to rise with age. After adjustment for age, gallstone disease was associated with higher body mass index and waist size in Bristol but not in Ladakh. It was associated with increased parity in Bristol, but not significantly so after adjusting for age and not at all in Ladakh. Gallstone disease was not directly associated with bowel function but Ladakhis often reported their stools to be lumpy (42.4 vs. 26.5% of Bristol women) and seldom as soft or loose (6.4 vs. 42.5%), implying that their intestinal transit tends to be slow. CONCLUSION: Gallstones can be common in a population free of obesity but prone to intestinal stasis.

Adult↗