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Biomedical subjects

K W Heaton

Publications and source records attributed to K W Heaton.

At least 37 records · Page 2Linked to original sources
PubMed1997

The intestinal effects of bran-like plastic particles: is the concept of 'roughage' valid after all?

OBJECTIVE: The mechanisms by which dietary fibre exerts is laxative action are not fully understood. Studies using sliced plastic tubing as a fibre substitute showed a decrease in both small and large bowel transit time. The significance of these studies is hard to interpret. We set out to compare the effects on intestinal function of wheat bran with plastic flakes similar in size and flaky shape to wheat bran (and devoid of plasticizers). DESIGN AND METHODS: Volunteers consumed coarse wheat bran then, after a washout period, plastic flakes of the same size and shape as the bran. Before and after each intervention whole-gut transit time (WGTT), defecation frequency, stool form, stool water content, stool beta-glucuronidase activity and dietary intake were assessed. RESULTS: Twenty-nine volunteers consumed a mean of 27.1 g of raw wheat bran and 24 g of plastic flakes a day. Baseline WGTT, interdefecatory intervals (IDI), stool form, weight, output, water content, and beta-glucuronidase were similar before both interventions. Both led to a decrease in mean faecal beta-glucuronidase activity, median WGTT (bran 25.8%, plastic 28.6%) and IDI (bran 23.3% plastic 25.0%). Both also increased stool form score (bran 28.6%, plastic 21.2%) and stool output (bran 67.1%, plastic 79.0%). Stool water content only rose with wheat bran (72%-75%, P = 0.014). CONCLUSION: Overall, plastic 'pseudobran' was as effective at altering colonic function as wheat bran at a similar dosage but with fewer particles. The mechanism is not by increased faecal water. Reduction in enzyme activity with plastic flakes suggests that the plastic led to qualitative and, probably, beneficial changes in the bacterial flora or their metabolic processes. The concept of roughage deserves to be revived.

Adult↗
PubMed1997

Irritable bowel syndrome: the view from general practice.

OBJECTIVE: To determine the attributes of the irritable bowel syndrome (IBS) in general practice as perceived by the doctors. SUBJECTS AND METHODS: We administered a 93-item questionnaire about the terminology, diagnosis and treatment of the irritable bowel to 43 of 55 randomly selected general practitioners (28 men, 15 women). RESULTS: General practitioners were unfamiliar with the Manning criteria for the irritable bowel syndrome. Nevertheless, most of them diagnosed the irritable bowel with reasonable confidence and it is less troublesome to them than pelvic pain, headache or backache. Their main concern was excluding organic disease (63%) and 65% believed their patients shared this concern. Nevertheless, they ordered few tests and were often (72%) prepared to make the diagnosis on the initial visit. They estimated that they referred only 14% of IBS patients to specialists, in most cases (56%) because of an unsatisfied patient and in 35% because of an uncertain diagnosis. For treatment, most (77%) chose 'explanation and reassurance'. Virtually all employed drugs, usually several. CONCLUSION: General practitioners say they diagnose the irritable bowel syndrome with less difficulty than other common, painful disorders, but it would be helpful to find out exactly how they do so. Their confidence could be increased by use of diagnostic criteria. Patients referred to specialists are likely to be a minority of hard-to-satisfy people. The optimal approach to such patients should be developed by general practitioners and specialists together. Specialists should strive to satisfy the patient and confirm the diagnosis in the few that are referred. Drug usuage in the irritable bowel syndrome is more than is justified and should, in our view, be minimized.

Adult↗
PubMed1997

Increasing butyrate concentration in the distal colon by accelerating intestinal transit.

BACKGROUND: Populations at low risk of colonic cancer consume large amounts of fibre and starch and pass acid, bulky stools. One short chain fatty acid (SCFA), butyrate, is the colon's main energy source and inhibits malignant transformation in vitro. AIM: To test the hypothesis that altering colonic transit rate alters colonic pH and the SCFA content of the stools. PATIENTS: Thirteen healthy adults recruited by advertisement. METHODS: Volunteers consumed, in turn, wheat bran, senna and loperamide, each for nine days with a two week washout period between study periods, dietary intake being unchanged. Before, and in the last four days of each intervention, whole gut transit time (WGTT), defaecation frequency, stool form, stool beta-glucuronidase activity, stool pH, stool SCFA concentrations and intracolonic pH (using a radiotelemetry capsule for continuous monitoring) were assessed. RESULTS: WGTT decreased, stool, output and frequency increased with wheat bran and senna, vice versa with loperamide. The pH was similar in the distal colon and stool. Distal colonic pH fell with wheat bran and senna and tended to increase with loperamide. Faecal SCFA concentrations, including butyrate, increased with senna and fell with loperamide. With wheat bran the changes were non-significant, possibly because of the short duration of the study. Baseline WGTT correlated with faecal SCFA concentration (r = -0.511, p = 0.001), with faecal butyrate (r = -0.577, p < 0.001) and with distal colonic pH (r = 0.359, p = 0.029). CONCLUSION: Bowel transit rate is a determinant of stool SCFA concentration including butyrate and distal colonic pH. This may explain the inter-relations between colonic cancer, dietary fibre intake, stool output, and stool pH.

Adult↗
PubMed1997

Stool form scale as a useful guide to intestinal transit time.

BACKGROUND: Stool form scales are a simple method of assessing intestinal transit rate but are not widely used in clinical practice or research, possibly because of the lack of evidence that they are responsive to changes in transit time. We set out to assess the responsiveness of the Bristol stool form scale to change in transit time. METHODS: Sixty-six volunteers had their whole-gut transit time (WGTT) measured with radiopaque marker pellets and their stools weighed, and they kept a diary of their stool form on a 7-point scale and of their defecatory frequency. WGTT was then altered with senna and loperamide, and the measurements were repeated. RESULTS: The base-line WGTT measurements correlated with defecatory frequency (r = 0.35, P = 0.005) and with stool output (r = -0.41, P = 0.001) but best with stool form (r = -0.54, P < 0.001). When the volunteers took senna (n = 44), the WGTT decreased, whereas defecatory frequency, stool form score, and stool output increased (all, P < 0.001). With loperamide (n = 43) all measurements changed in the opposite direction. Change in WGTT from base line correlated with change in defecatory frequency (r = 0.41, P < 0.001) and with change in stool output (n = -0.54, P < 0.001) but best with change in stool form (r = -0.65, P < 0.001). CONCLUSIONS: This study has shown that a stool form scale can be used to monitor change in intestinal function. Such scales have utility in both clinical practice and research.

Adult↗
PubMed1996

Repeated bile acid therapy for the long-term management of cholesterol gallstones.

BACKGROUND/AIMS: Following non-surgical treatment, cholesterol gallstones recur in a high proportion of patients, and recurrence cannot be predicted nor effectively prevented. Our aim was to test prospectively the viability and the efficacy of repeated bile acid therapy, in which recurrent stones are diagnosed at an early stage by regular ultrasound monitoring and promptly retreated, as a strategy for the management of these patients in clinical practice. METHODS: One hundred and seventy-two consecutive patients were recruited upon achieving complete gallstone dissolution using non-surgical therapy (bile acids or lithotripsy plus bile acids), and followed up at 6-monthly intervals by ultrasound scan. Gallstone recurrence was promptly treated by a combination of ursodeoxycholic acid plus chenodeoxycholic acid (5 mg/kg per day each) for a period of 2 years, or less if complete redissolution was achieved. Median follow-up period was 34 months (range 6-70). RESULTS: Forty-five patients had gallstone recurrence; of these, 39 underwent one or more repeated courses of bile acid therapy (follow-up data available in 27). Gallstone recurrence rate was 15% at 1 year and 47% at 5 years. Average annual redissolution rate of recurrent gallstones (intention to treat) was 41%. The proportion of gallstone-free patients in the whole population was 88%, 84%, 77%, 78%, 75% at 1-5 years, respectively, and rose to > 90% at 3 years onwards in patients with single primary stones. CONCLUSIONS: We conclude that repeated bile acid therapy maintains the majority of patients gallstone free, and is therefore an effective long-term management strategy, especially in patients with primary single gallstones.

Adolescent↗
PubMed1995

Is extrinsic sugar a vehicle for dietary fat?

Although many guidelines to healthy eating recommend restriction of the intake of extrinsic (refined) sugar, there are concerns that such restriction might result in an increase in the amount and the proportion of dietary fats with a consequent possible increase in the risk of cardiovascular disease. We used regression analysis to examine the determinants of fat intake in subjects from a population survey who had weighed their food for 4 days. In men (n = 77) and women (n = 83), fat eaten was positively related to the intake of extrinsic sugar. When intakes were expressed as percent of calories the relation became negative. A survey in a semi-random sample of 739 men aged 40-69 yr and 976 women aged 25-69 yr showed that, in both sexes, an increase in extrinsic sugar was associated with a linear increase in the intake of sweetened fat and hence of fat combined with carbohydrate. This was due mainly to a higher intake of cakes and biscuits. Foods containing sugar and fat provided an extra 12.0 g per day of fat in the men and 13.8 g per day in the women when the highest quartile of extrinsic sugar consumers were compared with the lowest quartile. We conclude that lowering the intake of extrinsic sugar is unlikely to be associated with higher fat intake. Instead extrinsic sugar may act as a vehicle for fat intake, encouraging consumption by making the fat more palatable.

Adult↗
PubMed1995

Prospective, multicenter study on value of computerized tomography (CT) in gallstone disease in predicting response to bile acid therapy.

The aim of the study was to assess the value of quantitative attenuation values (Hounsfield units) and of gallstone pattern by computerized tomography in predicting response to bile acid therapy. We carried out a prospective study in a multicenter setting on 90 consecutive outpatients with radiolucent gallstones. All received bile acid therapy (UDCA 10 mg/kg/day or UDCA + CDCA 5 mg/kg/day of each) up to two years. Hounsfield units for gallstones were recorded using standardized criteria and six categories of patterns were defined: hypodense, isodense, homogenously dense, laminated, rimmed and speckled. We assessed gallstone dissolution rate (percent reduction in volume), response to therapy (> 25% reduction in volume), and final outcome of therapy. Eighty-one percent of patients with hypodense/isodense and all four patients with speckled stone pattern responded to therapy, whereas none of the 10 patients with laminated/rimmed and only 45% of patients with homogenously dense stone pattern did. Complete dissolution was achieved by 68%, 50%, 35%, 0% of the hypodense/isodense, speckled, homogenously dense, rimmed/laminated gallstones, respectively. The use of Hounsfield units did not show an advantage over gallstone pattern for predicting either response or final outcome to bile acid therapy. We conclude that computerized tomography analysis of gallstones is of value in predicting response to bile acid therapy and that gallstone pattern alone predicts response in most cases without the need for quantitative assessment.

Chenodeoxycholic Acid↗
PubMed1995

Gastric emptying of a solid meal is accelerated by the removal of dietary fibre naturally present in food.

Exogenous fibre added to liquid meals delays gastric emptying. Its effect on solid meals is uncertain, and nothing is known of the effect on gastric emptying of fibre naturally present in food. This study therefore looked at gastric emptying of two different solid meals in eight healthy subjects and their blood glucose responses. The meals were exactly equivalent except for the total dietary fibre content (high fibre 20 g, low fibre 4 g of dietary fibre per 1000 kcal) and supplied 870 kcal (700 kcal women), 47% of which was from carbohydrates, 36% from fats, and 17% from proteins. Ultrasonography was used to measure antral diameters before the meal (basal), immediately after it (time 0), and at 30, 60, 120, 180, 240, and 300 minutes. In addition, subjects filled in a questionnaire on their feelings of hunger, epigastric fullness, and satiety before the meal and at hourly intervals after it. Basal and maximal postprandial antral sections were similar for the two meals (basal section: 283.9 (29.5) v 340.9 (44.7) mm2 for the low and the high fibre meal, NS; maximal postprandial section: 1726 (101.9) v 1593 (120.4) mm2, NS). Total gastric emptying time was significantly reduced by fibre removal (186.0 (15.6) v 231.7 (17.3) minutes after the low and the high fibre meal, p < 0.05). Blood glucose was higher after the low fibre meal, and the area under the glycaemic curve significantly greater (226 (23.1) v 160 (20.0) mmol/min/dl-1, p < 0.05). No difference was found in satiety or fullness feelings, but hunger returned more rapidly after the low fibre meal. In conclusion, fibre naturally present in food delays gastric emptying of a solid meal, reduces the glycaemic response, and delays the return of hunger.

Adult↗
PubMed1995

Acute respiratory distress secondary to Morgagni diaphragmatic herniation in an adult.

Diaphragmatic hernias of the Morgagni type are generally thought to be asymptomatic in adults. This traditional assumption led to a delay in diagnosing a Morgagni hernia as the cause of acute respiratory distress in a chronic schizophrenic man. While Morgagni hernias are usually considered to be long-standing, we present radiological evidence of an acutely expanding hernia. The patient's symptoms were relieved by surgical repair of the hernia. We advise caution before dismissing Morgagni hernias in adults as being long-standing and clinically insignificant.

Acute Disease↗
PubMed1995

Smoking habits and lipoproteins in British women.

The incidence of coronary heart disease is increasing in women. Some of this may be related to increased smoking in women over the past decades. However, the mechanism mediating the smoking-coronary heart disease link is unclear. We therefore assessed the relationship of smoking habits to fasting plasma insulin, total and low-density lipoprotein (LDL) cholesterol, triglyceride, high-density lipoprotein (HDL) cholesterol, including its subfractions HDL2 and HDL3, body mass index, and waist:hip circumference ratio in 1048 women aged 25-69 years. Compared with non-smokers, current smokers had higher plasma concentrations of LDL cholesterol by 0.2 mmol/l or 6%, total/HDL cholesterol ratio by 0.5 or 13%, triglyceride by 0.14 mmol/l or 13% and waist:hip ratio by 0.02 or 3%, but lower HDL cholesterol by 0.13 mmol/l or 9% and HDL2 cholesterol by 0.07 mmol/l or 13%, while ex-smokers had higher waist hip ratio by 0.01 or 1% but lower HDL cholesterol by 0.06 mmol/l or 4% and HDL2 cholesterol by 0.09 mmol/l or 16%. Ex-smokers for up to 5 years, compared with non-smokers, had higher plasma concentrations of total/HDL cholesterol ratio by 0.4 mmol/l or 11%, triglyceride by 0.22 mmol/l or 21% and waist hip ratio by 0.01 or 1%, but lower levels of HDL cholesterol by 0.12 mmol/l or 9% and HDL2 cholesterol by 0.14 mmol/l or 26%. Cigarette smoking is associated with adverse changes in lipoprotein levels; these changes decrease slowly after quitting.

Adult↗
PubMed1995

Some determinants of whole-gut transit time: a population-based study.

Slow whole-gut transit time may be associated with an increased risk of gallstones, and possibly bowel cancer, but its determinants are unknown. We looked for these determinants in a community-based study of 884 women aged 25-69 years and 677 men aged 40-69 years. Transit time was estimated using prospective examination of three stools and a questionnaire about bowel habit. Diet and alcohol intake were assessed using a validated food frequency questionnaire. In women < 50 years not taking oral contraceptives, mean transit time was relatively constant across 10-year age bands (62 to 63 h). In older women it was also relatively constant, but was significantly shorter (58 to 59 h), suggesting an effect of female sex hormones. In women taking oral contraceptives, mean transit-time was 6 h longer than in women of the same age not taking them (95% CI 1.4 to 10.6 h). In men drinking > 40 g alcohol/day, mean transit time was 49 h compared with 54 h in those drinking < 20 g/day (p < 0.0001). In alcohol-abstaining men, an effect of dietary NSP (non-starch polysaccharide or fibre) intake was clearly apparent. Alcohol consumption quickened transit in both sexes; oral contraceptive usage slowed it in women. Body mass index in both sexes, soluble NSP in men, and insoluble NSP in women also significantly and negatively affected transit time. The food groups which were related to transit time were potatoes and cooked fruit in men, and pulses and bread in women.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Irritable bowel syndrome in patients discharged from surgical wards with non-specific abdominal pain.

A questionnaire was used to discover the prevalence of seven recognized symptoms of irritable bowel syndrome (IBS) in 96 patients who had been discharged from hospital 1-2 years previously with the diagnosis of non-specific abdominal pain. Compared with 1897 controls from a population survey in the same city, the patients were more likely to have these symptoms; the differences were statistically significant in most cases. The frequency of recurrent abdominal pain with features suggesting an intestinal origin was increased fivefold in male and fourfold in female patients (P < 0.001). Criteria for the diagnosis of IBS were present in 37 per cent of women and 19 per cent of men, versus 5 and 2 per cent respectively in controls (P < 0.001). Approximately half the patients remembered having symptoms of IBS at the time of admission and 70 per cent had had other attacks of abdominal pain. At the time of admission, the hospital notes mentioned the possibility of IBS in only 6 per cent of cases. Most patients would have welcomed an explanation for the pain at the time of their hospital admission.

Abdominal Pain↗
PubMed1994

An office guide to whole-gut transit time. Patients' recollection of their stool form.

Forty-seven patients (ages 17-74 years, 33 women) who had irritable bowel syndrome and who attended a gastroenterology clinic had their whole-gut transit time (WGTT) assessed by an abdominal radiograph after ingesting 20 radioopaque markers on 4 consecutive days. Immediately afterward, the patients completed a questionnaire that asked about their stool form on the Bristol Scale, their bowel frequency, and whether they thought they had been experiencing diarrhea or constipation during the previous 5 days. WGTT varied from 7 to 96 h. Stool form correlated significantly with WGTT (r = -0.57, p < 0.001), whereas stool frequency did not (r = 0.31, NS). The regression equation relating WGTT to stool form was WGTT (h) = 75-10 (stool form). WGTT, stool form, and frequency were significantly different in patients reporting constipation compared with those who reported diarrhea, diarrhea and constipation, or neither, but in the last three groups these parameters were not significantly different from each other. Patients' recollection of stool form is a reasonable guide to their transit time and can be used in the office to identify pseudodiarrhea and true constipation.

Adult↗
PubMed1994

Evidence for the ambiguity of the term constipation: the role of irritable bowel syndrome.

A satisfactory definition of constipation is elusive. An important and measurable element is slow colonic transit. Whole gut transit time, a proxy for colonic transit time, can be estimated from self recorded data on stool form and frequency. Our aim was to compare whole gut transit time with subjective definitions in the context of the general population. In a community based sample of 731 women aged 25-69 years the estimated whole gut transit time was compared with two subjective assessments of constipation-the woman's own perception and a symptom based definition proposed by an international working team (Rome definition). We have defined slow whole gut transit time as > 2 SD above the mean in women who seldom passed lumpy stools (that is, > 92 hours). Slow transit was present in 9.3% of the sample. Similar numbers met the subjective definitions (8.5% and 8.2%). However, the overlap between the three definitions was poor. Of 68 women with estimated slow transit, 28 had self perceived constipation, 20 had Rome defined constipation, and only 11 had both. Of subjects classified as constipated by the subjective definitions only 37% had slow transit; they had a high prevalence of irritable bowel symptoms. In conclusion, this study showed that the term constipation is ambiguous and often misleading and that attempts to base a definition on symptoms are misguided. In epidemiological studies, conclusions about the prevalence of constipation should be based on records of stool type and timing.

Adult↗
PubMed1993

An explanation for gallstones in normal-weight women: slow intestinal transit.

Many cases of gallstones can be explained in terms of the established risk factors, especially obesity. However, gallstones develop in some women who are not obese, and the causes are unknown. Biochemical studies have shown that slow intestinal transit is associated with lithogenic bile. We have tested the hypothesis that intestinal transit is abnormally slow in normal-weight women with gallstones. In a population survey, 1058 women aged 25-69 years, registered with general practitioners in Bristol, UK, underwent cholecystosonography. Gallstones were identified in 48 women, of whom 15 were of normal weight (body mass index < or = 25 kg/m2). These women and age-matched controls with healthy gallbladders then underwent measurement of whole-gut transit time (WGTT); the measurement was done directly when possible, or calculated from records of three defaecations. The mean WGTT was significantly longer in the women with gallstones than in the controls (82 vs 63 h; mean difference 19, 95% CI 2-37 h). Stool output was also lower in the women with gallstones (74 [SD 54] vs 141 [56] g per 24 h, p = 0.015). There was no significant difference between cases and controls in body mass index, waist-hip circumference ratio, parity, plasma triglyceride concentration, or alcohol intake. Normal-weight women with gallstones tend to have slow intestinal transit and this feature could explain why they have gallstones.

Adult↗
PubMed1993

Straining at stool and laxative taking in an English population.

A population-based sample of 834 men (ages 40-69 years) and 1058 women (25-29 years) was investigated with respect to straining to defecate, stool form, bowel habit, and use of laxatives, by means of a questionnaire and a three-stool record form. Straining was common but, contrary to standard teaching, far from universal. It was unrelated to age but was commoner in women than men. Many people underestimated how often they strained. Overall, 32% of defecations in women and 22% of defecations in men were associated with straining to start and 15% and 9%, respectively, with straining to finish. Straining was to some extent related to stool type: the lumpier a stool, the more often it elicited straining. However, it seems likely that straining in some people is just a habit. Use of laxatives was found to be less prevalent than in the past, and most people with evidence of constipation did not use them. Use of laxatives increased with age, and some older people used them inappropriately. The most popular laxatives were based on phenolphthalein, senna, or magnesium.

Adult↗