Studies on nonesterified fatty acids in diabetes mellitus

Abstract

I measured the NEFA level of plasma in 98 diabetic patients by the Dole's method and persued the relationship between NEFA and carbohydrate metabolism experimentally.1) Foundamental experimentThe plasma NEFA level and blood sugar decreased with the administration of insulin in vivo, while with the administration of glucose the plasma NEFA level decreased and blood sugar increased.In vitro, the adipose tissue of rat releases NEFA. The rate of evolution of NEFA increased by the addition of adrenalin to the medium and decreased by the addition of insulin or glucose.The plasma NEFA level elevated in the Vitamin B1, B2, B6 and Pantothenic acid deficient rats. It was conceivable that the carbohydrate metabolism was impaired by these Vitamin deficiencies and its deficient energy was supplemented from the depot fat.2) Clinical experimentIn normal subject, the plasma NEFA level was found to be between 400 and 800 μEq./L. with the average of 637 μEq./L.. In diabetic patients, the plasma NEFA level tended to elevate at the average level of 740μEq./L.. Particurally in severe diabetic patients, whose blood sugar levels were over 200 mg/dl, the plasma NEFA level averaged 989μEq./L. and remarkably elevated in the cases with ketonuria.There was no correlation between the elevation of plasma NEFA level and the duration of diabetes mellitus. Also no intimate relationship between the vascular complication and the plasma NEFA level was found.After the treatment with insulin, sulfonylurea and DBI, the abnormality of plasma NEFA level was improved and insulin was most effective. The treatment with pyridoxal phosphate in diabetic patient with vascular complications showed the improvement of metabolic defects in diabetes and the decrease of high plasma NEFA level. However, with the administration of dextran sulfate, the plasma NEFA level increased and the lipoprotein lipase activity increased. This indicated that the plasma NEFA level increased by the increased lipoprotein lipase activity. So the administration of dextran sulfate in diabetic patients with vascular complications may be effective in order to improve or to protect arteriosclerosis.From these results, it is obvious that the plasma NEFA level has an intimate relationship with the carbohydrate metabolism. It was assumed that the measurement of plasma NEFA is important in order to know the carbohydrate and fat metabolism disorders in diabetes.