A randomised controlled trial of the effect of low fat diet advice on dietary response in insulin independent diabetic women.

Type 2 (insulin independent) diabetic women were randomly allocated to receive advice for low fat diets or low carbohydrate diets. By 24 h weighted dietary intakes before and after a mean interval of six months, patients in the low fat group had reduced their fat intake from 41% to 31% of total energy, while carbohydrate percentage of total energy intake increased from 38% to 46%. Percentage energy intake from fat and carbohydrate in the control group remained unchanged. Body weight fell in both groups especially for patients in the low fat group who were obese (weight/height2 greater than or equal to 28 kg/m2). Mean plasma glucose, HbA1, and triglycerides were unchanged. Mean plasma total cholesterol fell significantly in the low fat group compared with the controls (p less than 0.001), but there was no significant difference in the small reduction of high density lipoprotein cholesterol observed in both groups. Thus, adherence to low fat diets occurred without deterioration of diabetes and with benefit for weight and total cholesterol.

Diet in Crohn's disease two studies of current and previous habits in newly diagnosed patients.

The consumption of sugar and sugar-containing foods in 32 patients with recently diagnosed Crohn's disease was significantly greater than in matched controls; the assessment was made by a questionnaire and depended upon patients recalling their eating habits. In a further study of 16 patients with Crohn's disease, all food eaten over 5 days was weighed and recorded, and no significant difference was found in the consumption of carbohydrate, protein, fats, or sugars, although the consumption of "added sugars" in patients was greater than controls. Patients who participated in both studies significantly reduced their intake of added sugar, and this was not found to correlate with either total intake of monosaccharides and disaccharides or the total carbohydrate consumption. The increased consumption of added sugar in patients with Crohn's disease does not appear to be related to other dietary abnormalities and may simply reflect a deficiency in perception of sweet taste in patients with this condition.

The reproducibility of serial meal and oral glucose tolerance tests in normal subjects.

Five normal volunteer subjects within 10% of their ideal body weight received four isocaloric meals per day during two separate study periods. Each study period consisted of two consecutive days one week apart. The plasma glucose and insulin response was determined half-hourly throughout the second day of each of the two study periods. Good reproducibility of the glucose and insulin response to the standardised meals on the two comparative profile days was observed. Only at three points during the day was the plasma glucose significantly different between the profile days while no differences existed for plasma insulin. In addition, a separate group of four healthy normal volunteer subjects within 10% of their ideal body weight received four 50 g oral glucose tolerance tests on each of four days, ie on two consecutive days one week apart. During the second day of each study period half-hourly plasma glucose and insulin concentrations were determined. The within subject reproducibility of the plasma glucose and insulin response to the serial glucose loads was excellent. At one time point only was the mean plasma glucose for the group significantly different between the two study days. No statistically significant difference however was observed for the plasma insulin response between the two days. As the day progressed during both test procedures a small decrease in carbohydrate tolerance was observed. The amplitude of glycaemic excursions in response to the oral glucose tolerance tests was greater than that observed in response to the meal tolerance tests.

The effect of glibenclamide on the glucose and insulin profile in maturity onset diabetics following both acute and long term treatment.

Glibenclamide was administered to five non insulin dependent diabetic (NIDD) patients, whose hyperglycaemia was not controlled by diet alone. The plasma glucose and insulin porfile was determined under strictly standardised conditions before, after the first administration and after 6 months of treatment with glibenclamide. A rapid and satisfactory lowering of plasma glucose was observed in all patients after the first administered dose and a very similar response was seen after 6 months of therapy, when glibenclamide was administered once a day. Despite a consistent plasma glucose lowering effect a very variable plasma insulin response was evident between the patients. This difference may be of relevance in the long term prognosis of these patients with respect to atherogenesis. For the period of the study weight gain was minimal, no episodes of hypoglycaemia or alcohol induced flushing were recorded.

Comparison of the metabolic response to a glucose tolerance test and a standardized test meal and the response to serial test meals in normal healthy subjects.

The plasma glucose and insulin response to a standardized meal test breakfast was compared with the time-honored glucose tolerance test in the same normal healthy subjects. The amplitude of glycemic excursion and between-subject variation was less with the more physiologic standardized test meal than with that seen with the glucose tolerance test. The glucose tolerance test's prime function is to amplify any glucose intolerance, thus aiding diagnosis, whereas a standardized meal gives a more clinically relevant metabolic status. The administration of serial test meals during the same day in a smaller group of normal subjects indicated, as seen previously with repeated glucose tolerance tests, a diminishing carbohydrate tolerance during the day.

Repeated blood glucose and plasma insulin levels in normal volunteer subjects receiving isocaloric meals, before and after chlorpropamide and glibenclamide.

The blood glucose and plasma insulin response to the two hypoglycaemic agents, chlorpropamide (Diabenese) and glibenclamide (Daonil) was determined in normal subjects under strict metabolic control in a double blind study. The subjects were admitted to hospital for the period of the study, during which time they received four isocaloric meals per day and their physical exercise was standardised. Chlorpropamide had a prolonged hypoglycaemic effect compared with the short lived response after glibenclamide. Thy hypoglycaemic characteristics of the two preparations could not be explained simply on the insulin responses. Chlorpropamide was capable of lowering blood glucose without raising plasma insulin levels, whereas glibenclamide produced a prolonged and marked increase in plasma insulin levels only to be associated with a short-lived hypoglycaemic response. The latter suggested that a degree of insulin resistance had been produced secondary to the early profound lowering of the blood glucose following glibenclamide. The data indicate therefore the need for caution in extrapolating to diabetic subjects the hypoglycaemic characteristics of an agent such as glibenclamide derived from studies in normal subjects.