DEFINITION.—By the term hepatic glycosuria in this connection is meant a temporary glycosuria due to excessive formation of glycogen. The liver, unduly stimulated, produces more glycogen than can be disposed of, and hence it is excreted by the kidneys as grape-sugar.
PATHOGENY.—In the normal condition it is supposed that the glycogen produced by the liver is converted into grape-sugar, and soon oxidized and thus consumed. One theory of diabetes maintained that in some way the conversion of glycogen into grape-sugar was excessive and beyond the oxidizing power of the blood, and hence this substance was discharged in the urine. The recent discovery by Pavy11 of glycogen in considerable amount in the blood of all parts of the body renders it certain that there are peculiar conditions necessary to the formation of grape-sugar in sufficient quantity to constitute diabetes. It is tolerably certain that an excess of acid in the intestinal canal, diminishing thus the alkalinity of the blood, will have as a symptom sugar in the urine. Persons disposed to the accumulation of fat, and eating freely of sugar and starchy food, are apt to have intestinal indigestion, and the acid produced by the fermentation of these substances will, after its absorption, hinder the conversion of any food-sugar. In such subjects also there may be an increased conversion of the glycogen of the blood into sugar under the same conditions. Such a glycosuria must necessarily be temporary and a purely functional disorder.
11 The Lancet, vol. ii., 1883.
SYMPTOMS.—The subjects of the malady under consideration are of full habit, even obese. They habitually consume considerable quantities of malt liquors and a diet composed largely of the starchy and saccharine foods. If not in malt liquors, they at least indulge freely in bread, potatoes, pastry, cakes—in all forms of farinaceous food, fats, and sweets. They have a keen appetite, eat largely, and drink freely of fluids. As a rule, these subjects are but little disposed to physical exercise and lead rather sedentary lives. Indulgence in such a mode of life tends to increase the accumulation of fat, weakens the muscles, and with them the heart-muscle, and slowly induces a gastro-intestinal catarrh accompanied by stomachal and intestinal indigestion. At first, heaviness, oppression, and drowsiness after meals are experienced; then acidity, pyrosis, and eructations follow; and ultimately the evidences of intestinal indigestion—flatulence, pain, irregular and unhealthy evacuations, etc.—come on. Meanwhile, the appetite is not usually impaired, and the disposition to drink fluids increases; the amount of urine voided is greater, and to rise during the night for the purpose of emptying the bladder comes to be a fixed habit. The urine under these circumstances is copious, high-colored, acid, and deposits on cooling abundantly of uric acid and urates. The amount passed in twenty-four hours will reach sixty, eighty, or more ounces, and the specific gravity will range from 1025 to 1035. On testing in the usual way, traces of sugar, more or less distinct, will appear,12 but not constantly, and hence repeated examinations are necessary to determine the quantity. As a rule, the evidence of the presence of sugar in small amount is satisfactory.
12 In testing for sugar, when the urine contains the urates in such abundance there is danger of error. In using Trommer's, Fehling's, or Moore's test, on heating, the urates will effect a reduction of the copper or bismuth. It is necessary, therefore, to separate them before applying the test. This is accomplished as follows: The urine is evaporated to dryness on a water-bath; the sugar in the evaporated residue is dissolved out by absolute alcohol, and then an aqueous solution is prepared, to which the test is applied. An experienced operator will not need to take such precautions, for, familiar with the reactions, he can readily judge of the results.
Various affections of the skin appear in the subjects of this malady, and urticaria, prurigo, eczema, and boils are the forms most usual.
COURSE, DURATION, AND TERMINATION.—Slow in developing, this temporary glycosuria is also slow in its course. It remains nearly stationary for months, even years. Meanwhile the degenerative changes associated with it slowly develop on all sides. The quantity of sugar does not greatly increase, for its amount, being apparently dependent on the quantity of acid entering the blood from the intestinal canal, must continue nearly at the same standard. It is comparatively rare for true diabetes to develop out of this state, although such a termination must be regarded as a natural outcome. One reason, it may be, why such a conclusion is not often reached is because of intercurrent maladies. It is an important fact that acute serous—less often parenchymatous—inflammations are very apt to occur during the existence of even temporary glycosuria. Under appropriate management this disorder is readily amenable to treatment. Hence the prognosis will be favorable or not according to the skill exhibited in its treatment.
DIAGNOSIS.—This malady offers no special difficulty in diagnosis. From gastro-duodenal catarrh and from lithæmia it is distinguished by the saccharine condition of the urine. From diabetes it is separated by the rate of progress, by the protracted duration of the case without any distinct advance, and by the temporary and fugitive character of the glycosuria.
TREATMENT.—To carefully regulate the diet is the first consideration. The traces of sugar and the excess of urates rapidly disappear when the starches, sugar, and fats are withdrawn from the diet. Indeed, the rule as to alimentation must be as rigidly enforced as in true diabetes, but after the gastro-intestinal catarrh has subsided the ordinary mixed diet—that before the disturbance began—may be returned to gradually. Active exercise must be enjoined under the same conditions and for the same purpose as in the treatment of lithæmia. In these obese subjects, unaccustomed to movement, exercise must be cautiously undertaken; beginning with short excursions, it must be gradually increased. Horseback riding is an excellent expedient, but should not take the place of walking.
The merely medical measures have a twofold direction: to remove the gastro-duodenal catarrh; to promote oxidation of the sugar in the blood or prevent the conversion of glycogen into grape-sugar. Vichy water, the potash salts, and alkalies generally serve to accomplish the latter, and phosphate and arseniate of soda, tinctures of nux vomica, and of physostigma, bismuth, and carbolic acid, relieve the former. Small doses of Fowler's solution (two drops ter in die), and a minim three times a day of a mixture in equal parts of tincture of iodine and carbolic acid, are effective remedies in gastro-duodenal catarrh.