Two Cases of Diabetes Mellitus

Abstract

For a long time it has been recognized that glucose tolerance is increased in patients with hypothyroidism and that diabetes mellitus is aggravated by coexisting hyperthyroidism. ^{1, 2} Attention also has been called to the fact that diabetes is more common in the presence of hyperthyroidism than in its absence.³ The mechanism by which hyperthyroidism produces diabetes-like metabolic changes appears to be as follows: The rate of oxidation of carbohydrates by the tissues of the body is increased. This results in a rapid flow of stored sugar from the liver into the blood stream tending to deplete the liver stores.⁴ Because the absorption rate of glucose from the intestine is accelerated, the post-prandial rise of blood sugar is further exaggerated.⁵ Meanwhile, the liver is further depleted because of an increased rate of oxidation within its cells. Thus the whole picture rather closely simulates that found in diabetes mellitus. For the same reasons latent diabetes may manifest itself, and existing diabetes may become more severe in the presence of hyperthyroidism.

In myxedema the whole process is reversed. The ameliorating effect of thyroidectomy upon diabetes mellitus has been tested clinically⁶ and has not been found to be of practical therapeutic value. Cases of diabetes and myxedema thus present an unusual and interesting metabolic picture. They prove that thyroidectomy cannot be expected to have a curative effect on diabetes mellitus. Diabetes and myxedema have coexisted in five cases which have come under my supervision. One of these is reported here.

Case 1. The. . .