EFFECTS OF GLYCOSURIA UPON NUTRITION AND METABOLISM.
(Emaciation, Polyphagia, Proteid Decomposition.) Our present knowledge concerning the consumption of nutrient material and its relations to force and heat production in the body enables us to obtain a clear understanding of the consequences which glycosuria must bring with it as regards metabolic equilibrium.
1. Calorie-change, General Aratrition."—It was formerly believed that the process of oxidatiOn is lowered in the diabetic organism, that is to say, that the kilogram of protoplasm requires for the exer tion of the same force less fuel, consumes less oxygen, and sets free less CO„ than in health. This view was in notable conflict with the law of the conservation of force. The works of Carl von Voit, Leo, Weintraud, and Laves show that the diabetic converts just as much potential energy into living force as the healthy individual. Between the diabetic and the healthy individual at rest, and between the working diabetic and the working healthy man there is in this re spect no difference.
Before entering upon a study of the special conditions obtaining in the diabetic, a few physiological considerations must be premised. Following the suggestion of Rubner it has become usual to measure the manifestation of force which reaches its development through oxidation processes in the body by the physical unit value of the calorie (heat-unit). By the word calorie is understood the amount of heat necessary to raise one kilogram of water 1° C. Careful inves tigations have shown that every one of our nutritive substances by its consumption in the body produces an exactly definite amount of heat or the mechanical equivalent of this measure in the form of energy.
Further investigations have established the value as fuel of the materials daily consumed in the body. An adult man consumes in the twenty-four hours, per kilogram of body weight, material to the value of 30 to 35 calories, when at rest.
35 to 40 calories, when in motion and engaged in light work. 40 to 50 calories, when engaged in labor of moderate severity.
In order that the body may maintain its metabolic equilibrium the output must be met by an equivalent income of nutritive material, otherwise emaciation takes place.
Au example will explain the position of the diabetic sufferer: Mrs. B., 32 years of age, weighing 55 kilograms (121 pounds), occupied with light employment. Her nutritive needs were esti mated at 55 x 35 = 1,925 calories. She took daily for five days : She excreted a daily average of 141 gm. of sugar and lost in this
way each day nutritive material to the value of 141 x4.1 = 578 cal ories. The food taken had for her, therefore, the value of only 2,293 —578 = 1,715 calories. As we estimated the nutritive needs at 1,925 calories, there was a daily deficit of 1,925-1,715 = 210 calories.
The body must, therefore, in order to meet the requirements of energy and heat production, have consumed of its own substance to the value of 210 calories. In this case we were able to determine what substances these were. The patient ingested each day 148 gm. albumin, containing 23.68 gm. nitrogen. In the urine there was found on an average 23.3 gm. nitrogen, and in the feces an average of 1.9 gm. nitrogen—a total of 25.2 gm. nitrogen. The patient con sequently lost a daily amount of 2.5.2-23.68 = 1.52 gm. nitrogen, corresponding to a loss each day of 9.5 gm. albumin. Through the decomposition of 9.5 gm. albumin are produced 9.5 x4.1=38.9 cal ories. There remain, therefore, 210-38.9=171 calories to be pro duced, which production must be obtained by the consumption of some non-nitrogenous substance. The only substance which enters into consideration is fat. In order to produce 171 calories 18.4 gm. of fat must be burned up (15.4x9.3=171).
We see from this that a diet which would be a liberal allowance for a healthy person may be insufficient for one with diabetes. The diabetic must accordingly, in order not to waste away, either live ou a mixed diet of higher calorie value than a healthy person, or else so compose a diet corresponding to his needs that a loss of sugar to any considerable degree may be prevented. He must from the nature of the case resort to albumivates and fat. An individual suffering from a severer grade of diabetes cannot be nourished by carbohydrates, for they would pass through him uncousumed like water through a sieve. (See the section on Treatment.) We now understand the remarkable nutritive requirements, the polyphagia, of the diabetic. The sufferer from this disease, whose diet is not regulated by medical advice, swallows great quantities of food including much carbohydrate. The "stomach hunger" is momentarily stilled, but quickly returns, for the "tissue hunger" is not satisfied. The inordinate appetite of the diabetic disappears only when the useless carbohydrates are cut off and their place supplied by albumin and fat. When this is clone the emaciation of the patient comes to a halt with the relief of the polyphagia.