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Biomedical subjects

K W Heaton

Publications and source records attributed to K W Heaton.

At least 91 records · Page 5Linked to original sources
PubMed1986

Intestinal transit, deoxycholic acid and the cholesterol saturation of bile--three inter-related factors.

There is considerable evidence that the level of deoxycholic acid in the bile influences biliary cholesterol saturation. Deoxycholic acid is formed in the colon and absorbed slowly. Hence changes in colonic transit rate might influence biliary deoxycholic acid and the cholesterol saturation of bile. When 14 constipated subjects took standardised senna tablets for six weeks in a dose sufficient to lower mean whole gut transit time from 134 to 54 hours, deoxycholic acid as a proportion of biliary bile acids fell from 25.9 +/- 8.6 to 17.2 +/- 8.3% (p less than 0.0001) and deoxycholic acid pool measured by isotope dilution fell from 0.64 +/- 0.34 to 0.45 +/- 0.29 g (p less than 0.0001). In those subjects (n = 8) whose bile was initially supersaturated with cholesterol, the saturation index fell from 1.40 +/- 0.22 to 1.20 +/- 0.19 (p = 0.02). Conversely, when 12 normal volunteers took loperamide capsules sufficient to cause symptomatic constipation and to prolong mean transit-time from 48 to 103 hours, the deoxycholic acid pool increased from 0.40 +/- 0.24 to 0.57 +/- 0.17 g (p = 0.008). The percentage deoxycholic acid did not alter significantly, because the estimated total bile acid pool expanded (from 1.98 +/- 0.61 to 2.81 +/- 0.48 g; p less than 0.001), presumably because of loperamide slowing down small bowel transit. Despite this expansion of the bile acid pool, loperamide increased the cholesterol saturation index from 1.10 +/- 0.31 to 1.20 +/- 0.32 (p = 0.01). Changes in colonic transit rate alter the size of the deoxycholic acid pool and bile cholesterol saturation. These findings suggest that constipation or slow colonic transit might increase the chance of supersaturated bile and hence of gall stones.

Adult↗
PubMed1986

Effects of a new, concentrated wheat fibre preparation on intestinal transit, deoxycholic acid metabolism and the composition of bile.

When the cholesterol saturation index of bile is reduced by wheat bran there is generally a fall in the deoxycholic acid content of bile. As the same effects occur with senna, bran might act on bile simply via its accelerating effect on colonic transit. We have studied the effects of a new, concentrated, wheat fibre preparation (Testa Triticum Tricum, Trifyba, which is 80% dietary fibre) upon bile composition, deoxycholic acid metabolism and intestinal transit time, and have assessed whether these effects are related. Twenty constipated volunteers were prescribed Testa Triticum Tricum in doses (10-32 g/day) sufficient to relieve their symptoms for at least six weeks. Before and at the end of this period, duodenal bile was sampled to enable measurement of deoxycholic acid pool (by isotope dilution), total bile acid pool, bile acid composition and cholesterol saturation index. Whole gut transit time fell from 120 +/- SD35 to 68 +/- 35 hours. At the same time, biliary % deoxycholic acid fell from 26.6 +/- 12.0 to 23.0 +/- 11.8 (p = 0.002), the total bile acid pool expanded from 2.36 +/- 0.88 to 2.75 +/- 0.90 g (p = 0.008) and cholesterol saturation index fell from 1.13 +/- 0.32 to 1.07 +/- 0.29 (p = 0.04). In subjects with initial cholesterol saturation index over 1.0 (n = 12), it fell from 1.33 +/- 0.25 to 1.22 +/- 0.21 (p = 0.008). There was no significant correlation between change in saturation index and change in % deoxycholic acid or deoxycholic acid pool, nor between any of these parameters and change in transit time. Testa Triticum Tricum reduces the cholesterol saturation index of supersaturated bile but this action appears to be independent of its effect on colonic transit and of changes in deoxycholic acid metabolism.

Adult↗
PubMed1985

Sugar, fat, and the risk of colorectal cancer.

The habitual diet of 50 patients with large bowel cancer, as assessed by a dietary history method, was compared with that of 50 closely matched controls. Patients were included only if their symptoms were unlikely to have changed previous eating habits. The mean daily intakes of all major nutrient classes and of dietary fibre were estimated. Patients with large bowel cancer consumed 16% more energy than controls (mean (SEM) daily intake 9.92 (0.41) v 8.56 (0.32) MJ (2370 (98) v 2046 (76) kcal), respectively; p less than 0.0001), mainly in the form of carbohydrate (21% more; 282.6 (13.7) v 233.4 (10.5) g; p less than 0.0001) and fat (14% more; 100.8 (4.3) v 88.4 (3.2) g; p less than 0.001). The extra carbohydrate was largely in the form of sugars depleted in fibre and the extra fat as combinations of fat and such sugars. As the selection criteria used make it unlikely that this eating pattern was caused by the disease the data suggest that a high intake of sugars depleted in fibre and fat predisposes to the development of large bowel cancer.

Adult↗
PubMed1984

Effects of dietary sucrose on factors influencing cholesterol gall stone formation.

Twelve subjects with radiolucent gall stones and bile supersaturated with cholesterol were studied after six weeks each on diets which contained 112 g and 16 g respectively of refined (fibre depleted) sucrose but which allowed free access to other foods. Energy intake was 24.5% higher on the high sugar diet and body weight ended 1.4 kg higher than on the low sugar diet. Biliary secretion rates of cholesterol, phospholipid and bile acid, measured by a perfusion technique, were similar on the two diets, as were the bile acid pool sizes measured by isotope dilution. Cholesterol saturation index of fasting 'gall bladder' bile was 1.30 +/- 0.11 and 1.37 +/- 0.14 on high and low sugar respectively (NS). Plasma triglycerides were 36% higher and plasma high density lipoprotein cholesterol concentrations were 9% lower on the high sugar diet. These findings indicate that over a six week period refined sugar in normally consumed amounts does not adversely affect the lipid composition of bile.

Adult↗
PubMed1983

Diet and gall stones: effects of refined and unrefined carbohydrate diets on bile cholesterol saturation and bile acid metabolism.

It has been suggested that consumption of refined carbohydrate foods (notably sugar and white flour) increases bile cholesterol saturation and hence the risk of cholesterol gall stone formation. To test this hypothesis, 13 subjects with probable cholesterol gall stones ate refined and unrefined carbohydrate diets, each for six weeks in random order. On the refined carbohydrate diet, subjects ate more refined sugar (mean = SEM: 106 +/- 7 vs 6 +/- 1 g/day, p less than 0.001), less dietary fibre (13 +/- 1 vs 27 +/- 3 g/day, p less than 0.001), and had a higher energy intake (9.17 +/- 0.66 vs 7.16 +/- 0.64 MJ/day, p less than 0.001). After each diet, the lipid composition of duodenal bile and bile acid kinetics was determined. The cholesterol saturation index of bile was higher on the refined carbohydrate diet in all but one subject, with a mean value of 1.50 +/- 0.10 compared with 1.20 +/- 0.12 on the unrefined diet (p less than 0.005). On the refined carbohydrate diet, bile contained relatively less cholic acid and slightly more deoxycholic acid. There were, however, no significant differences in total or individual bile acid pool sizes. There were also no differences in the rates of primary bile acid synthesis or fractional turnover on the two diets. Consumption of carbohydrate in refined form increases bile cholesterol saturation. The risk of gall stones might be reduced by avoidance of refined carbohydrate foods.

Adult↗
PubMed1983

Empyema of the gall bladder - reappraisal of a neglected disease.

Thirty two patients with empyema of the gall bladder were identified among 1327 cases of gall-bladder disease presenting to one hospital over a six year period. Abdominal pain had been present for a median of eight days and, in eight cases, for between one and four months. In a few cases, the disease was painless and was discovered unexpectedly at postmortem or at operation for unrelated disease. The serious nature of the complaint was belied by the often scanty physical signs. Less than half the patients had a pyrexia of more than 37.5 degrees C and the presence of sepsis was rarely suspected clinically. Eight patients (25%) died, usually from unsuspected septicaemia. This considerable mortality might be reduced by the wider use of blood culture in cases of apparent 'cholecystitis' and by greater awareness that empyema of the gall bladder is sometimes chronic, painless, and afebrile.

Abdomen↗
PubMed1983

Not just fibre--the nutritional consequences of refined carbohydrate foods.

The dietary intake of 28 volunteers was assessed over two 6-week periods while they ate, alternately, a diet containing refined carbohydrate foods in commonly consumed amounts and a diet virtually devoid of such foods. The following nutritional effects of refined foods were observed: increased energy intake (except in low consumers of sugar), decreased intake of dietary fibre, and decreased intake of nearly all the vitamins and minerals recorded in tables of food composition. These effects may have harmful consequences.

Adult↗
PubMed1982

Assessment of the metabolic effects of dietary carbohydrate and fibre by measuring urinary excretion of C-peptide.

An assessment of the metabolic effect of dietary carbohydrate on daily insulin secretion, reflected by the 24-h urine output of C-peptide, has been made. Urinary C-peptide excretion increased when the carbohydrate intake of 6 normal subjects was increased from 200 to 400 g. A high-fibre diet rich in beans and lentils caused a significant fall in urine C-peptide and a lowering of blood glucose values in both normal and diabetic subjects. This confirms the insulin-sparing effect of leguminous foods. An increase of dietary fibre to 50 g mainly as cereal fibre did not significantly alter urine C-peptide excretion in normal subjects. Urinary C-peptide estimations could be useful for assessing the effect of different diets on daily insulin secretion.

Adult↗
PubMed1981

A relation between high-density-lipoprotein cholesterol and bile cholesterol saturation.

The association of cholesterol gall stones with coronary artery disease is controversial. To investigate this possible relation at the biochemical level, bile cholesterol saturation and the plasma concentrations of triglycerides, total cholesterol, and high-density-lipoprotein cholesterol (HDL cholesterol) were measured in 25 healthy, middle-aged women. Bile cholesterol saturation index was negatively correlated with HDL cholesterol. It was positively correlated with plasma triglycerides and with total cholesterol minus HDL cholesterol. These findings provide a biochemical basis for a positive association in women between cholesterol gall stones and coronary artery disease.

Adult↗