Abstract
Although diet regulation is a basal therapeutic means for diabetes, little is known about its primary effect on diabetic metabolism, including insulin secretion. The purpose of this investigation is to throw a light on this problem.
Twenty-two non-ketotic diabetics were selected for study, who were newly-diagnosed or had interrupted the treatment of diabetes for long time, having no other diseases which might affect carbohydrate metabolism.
In these patients, blood glucose, FFA and IRI response to oral loading of 100 g glucose were compared before and after 4 week diet regulation. The diet which was indicated to them was composed of 60% carbohydrate, 15-20% protein and 20-25% fat. The total calorie was restricted in relation to their weight and physical activity. The patients were asked to weigh their daily food. 24h intake of carbohydrate, protein and fat, and total calorie were calculated as accurately as possible. According to this calculation, dietetic intakes of seven of these twenty-two patients were found not to be significantly changed between before and after the instruction of diet regulation. Therefore, we divided all patients studied into two groups, namely control group (7 cases) and diet treatment group (15 cases).
After the diet regulation in the latter group, fasting glucose was decreased from 164.1±14.6 mg% to 121.7±7.1 mg%(p<0.01), glucose tolerance was significantly improved and insulin response estimated by measuring the area under the curve was increased from 6, 807±958 μU·min/m/ to 10, 392±1, 657 μU·Eminim/(p<0.01) in spite of lowered level of blood glucose. However, the sluggishness in early insulin response to glucose was not markedly changed. Insulinogenic index was also significantly increased at 180 minutes after oral glucose loading. Plasma FFA response to oral glucose was ameliorated at 120 minutes.
On the other hand, the control group did not show any significant changes in blood glucose and IRI and FFA response to glucose loading before and after 4 week observation periods.
Therefore, the metabolic effects of the diet regulation should be at least in part ascribed to the increased secretion of insulin. These results support the classical concept, “Resting the Pancreas”, brought about by caloric restriction.
