Colloidal nitrogen in diabetes

Abstract

The so-called colloidal nitrogen fraction of the urine has normally a fairly constant relationship to the total nitrogen, forming from 1 to 4.5 per cent. of the latter. In a number of pathological conditions, the percentage may be greatly increased, rising in some instances to 35 per cent. In a study of this subject by Pribram and collaborators, it was found that in severe diabetes, among other diseases, the percentage of colloidal nitrogen was especially high. Pribram interprets this as an evidence of abnormal or lessened liver function and associates it with the occurrence of diabetic coma.

I have determined the colloidal nitrogen fraction in two cases of diabetes. The first was in diabetic coma, which had a fatal outcome. The analysis of the urine collected on the second day of coma gave the following figures: Total nitrogen, 7.78 g.; colloidal nitrogen, 0.22 g. The colloidal nitrogen fraction was 2.87 per cent. of the total nitrogen, a normal relationship.

The second case was one of moderately severe diabetes, with a moderate degree of acetonuria and glycosuria. One analysis gave: Total nitrogen, 14.84 g.; colloidal nitrogen, 0.91 g. The colloidal nitrogen was 6.2 per cent. of the total nitrogen.

An analysis made ten days later on the urine of this patient showed: Total nitrogen, 17.9 g.; colloidal nitrogen, 0.43 g.; colloidal nitrogen = 2.4 per cent. of total nitrogen.

According to these figures, which agree with some reported by Wolf and Marriott, there appears to be no definite relationship between the severity of diabetes and the urinary colloidal nitrogen percentage. It is quite possible, however, that the colloidal substance may fail to be increased in the urine because of faulty kidney elimination and that the blood content may be considerably above the normal without the urine showing any evidence of this.