THE DAILY AMOUNT OF SUGAR EXCRETED, AND ITS ESTIMATION - THE GLYCOSUBIA.
The amount of sugar excreted varies greatly in different cases and also at different times in the course of the same case. Some dia betics excrete only a few grams daily or even none at all, while in others the quantity of sugar passed in the urine in the twenty-four hours may amount almost to a kilogram (two pounds avoirdupois). Such excessive figures are, however, very rarely met with, although a daily excretion of from 300 to 500 grains (one-half to one pound) is not uncommon.
It is important to know the total amount excreted in a given case. To determine this the patient must be instructed to save all the urine passed in the twenty-four hours in a common receptacle. This quan tity is carefully measured, and then a sample is subjected to a quan titative analysis for sugar. It is very important to mix together all that is passed in the twenty-four hours, since the amount of sugar may vary considerably in the single portions voided at different times of the day.
After the percentage of sugar has been determined and the total amount of urine passed has been measured, we have still not done much to aid us in judging of the gravity of the case. We often hear the laity and even physicians express themselves somewhat as follows : "As regards the patient X matters are not so bad, for lie excretes only 2 per cent. of sugar in the urine ; but Y has a very grave form of dia
betes, for lie always has per cent. or more of sugar in his urine:" or similar comparisons are made concerning the daily amounts ex creted, as, for example, a case with a daily excretion of 50 grams is regarded without further consideration as less severe than one whose urine contains 250 grams in the twenty-four hours. Com parisons of this kind are justified only when the diet in the given cases is exactly the same, but they are utterly worthless and misleading when the food of the two patients varies in quantity and quality. When the nature of the diet is taken into consideration it may well be that the disease will be found to be actually much more grave in the patient who excretes the daily amount of only 50 grams than iu the one who passes 250 grams. This would be true, for exam ple, if the first patient carefully avoided the ingestion of food con taining carbohydrates, while the second indulged freely in articles rich in these substances.