2. Proteid Decomposition.' —The example just cited gives us an op portunity to discuss another point in the metabolism of the diabetic, namely, the albumin-change. It has for a long time been known that diabetic patients usually excrete a very considerable quantity of nitrogen (urea). Larger figures are not reached, indeed, in any other disease. Many authors, more particularly in France, have given a special name, azoturia, to this symptom. The azoturia is in great measure occasioned by the abpudant ingestion of proteids. Diabetics often take, in the form of meat, eggs, ham, sausage, etc., from 180 to 200 gin. or more of albumin. The excretion in the urine of the nitrogen herein contained—except for the small amount pass ing away in the feces—is a physiological process. The healthy man, who ordinarily does not take in more than half this amount of albu min, excreting usually from 14 to 16 gm. of nitrogen, would excrete proportionately large amounts of nitrogen if his diet were increased to the same extent.
The condition becomes a pathological one only when the amount of nitrogen in the urine exceeds that taken in with the food, in other words when, in addition to the albumin of the food, that of the tissues also is decomposed. This occurs in diabetics when, as in the example above given, so much sugar is excreted that after the subtraction of its heat value from the heat value of the food the latter is found to be insufficient. Whenever an individual eats less than the necessities
of his organism demand he loses in body substance, partly albumin and partly fat; in diabetics with little adipose tissue the loss of al bumin is always proportionately the greater, its nitrogen being added to that of the albumin of the food. This waste of nitrogen is the greater the more the food value is depreciated by glycosuria. It is very large as long as the diabetic is left to himself to ingest the car bohydrates which are useless to him, but becomes slight or ceases when the diet consists largely of proteids and fat (Lusk, F. Voit, von Noorden, Hirschfeld, Weintraud).
The loss of nitrogen may also reach a high figure as a result of the action of toxic substances upon the protoplasm. Substances of this kind prejudicial to the integrity of the protoplasm are probably often formed in diabetes. I refer particularly to the final stage of the dis ease, diabetic coma. Nevertheless the existence of an azoturia of toxic causation in diabetes has never been determined with certainty.