The effect of exercise upon the sugar secretion is not uniform. Bouchardat and Kuelz have noted a diminution, and even disappearance, of sugar from urine as its result, and it is reasonable to suppose that judicious exercise is at least without harmful effect, while it is certain too that muscular exercise, if excessive, will increase glycosuria.
Changes in diet of course modify the secretion of sugar, starches and saccharine foods increasing it, while nitrogenous and oily foods diminish it. So, too, the urine secreted on rising in the morning has almost always less sugar in it than that passed on retiring; and it is not rare to find no sugar in urine passed on rising, when that passed on retiring at night may contain a small amount of sugar—from ¼ to 1 per cent. On the other hand, I have found a small amount of sugar in the morning urine when the evening urine contained none. Anxiety and excitement both increase the proportion of sugar.
Inosite, or muscle-sugar, is sometimes associated in urine with diabetic sugar, and occasionally replaces it. So, too, in experiments upon animals puncture of the fourth ventricle is sometimes followed by inosuria instead of glycosuria, and in corresponding organic disease of the brain the same thing is observed. The substitution of grape-sugar by inosite in the course of diabetes is considered by Laboulbène27 a favorable change.
27 "Note sur l'Inosurie, succédant au diabète glycosurique, et paraissant avoir une action favorable," L'Union Médicale, Oct. 14, 1883.
As would be expected, the specific gravity of saccharine urine is usually high—most frequently from 1025 to 1040—and Bouchardat noted a specific gravity of 1074 in one instance. On the other hand, I have found sugar easily detectable in urine with a specific gravity as low as 1010. Pavy records an instance of the same specific gravity, and Dickinson one in which the specific gravity was as low as 1008. It is to be remembered that the sugar is rapidly destroyed when fermentation sets in. A coincident diminution in the urea and other solids of the urine will reduce the specific gravity of a saccharine urine otherwise heavier.
The depth of color of diabetic urine is inversely as the quantity passed. Hence, when this is very large the urine is pale, and even almost colorless, but it may still contain considerable amounts of sugar and possess a decided color, quite as deep as that of urine passed in smaller quantity. When exposed to the air, diabetic urine becomes rapidly turbid from the growth of fungi, including the yeast fungus and penicilium glaucum.
The odor of diabetic urine just passed is usually in no way peculiar, but as fermentation progresses an acetous odor is developed, which is ascribed to acetic acid. At other times the odor is quite peculiar, being spoken of as vinous or compared to that of sour beer, stale fruit, alcohol, chloroform, or, as by one of my patients, to sweetbrier.
Diabetic urine has almost invariably an acid reaction, which becomes more decided as fermentation progresses. As a consequence of this increased acidity, and sometimes independent of fermentation-changes, the urine deposits a sediment of uric acid, but with this exception diabetic urine is generally free from sediment. Diabetic patients on a meat diet sometimes have a good deal of uric acid from this source.
Albuminuria may coexist with glycosuria, but is not generally found until late in the disease, after changes in the kidney begin to make their appearance, unless, as may happen, glycosuria supervenes upon primary renal disease.
Alcohol and acetone, or an acetone-yielding substance—aceto-acetic acid—are sometimes found in diabetic urine. They are products of the breaking up of sugar, but chemists do not explicitly agree as to the exact method in which acetone originates in the organism. First recognized in the distillate of urine and blood of a diabetic patient by Petters28 through its physical properties, odor, combustibility, etc., rather than by actual isolation, it was further investigated by Kaulich,29 Gerhardt,30 Rupstein,31 and Markownikoff,32 who obtained it in an impure state from urine; by Deichmüller and Tollens,33 whose isolated substance was pure, and finally most recently by Jaksch34 and Penzoldt.35 The former found it not only in diabetic urine, but also in that of fever, and even of carcinoma. The latter found it by the indigo test in but 18 out of 22 diabetics, and by the iodoform test, either decidedly or feebly, in 20 out of 20; in 3 out of 11 cases of typhoid fever, in 6 out of 7 cases of pneumonia, in none of 6 cases of phthisis, in 1 out of 3 cases of measles, and in 1 case of cerebro-spinal meningitis. Finally, v. Jaksch has been led to believe, from his extensive investigations, that acetone is a constant and normal product of tissue-change, although Penzoldt considers such conclusion scarcely justified.