Diabetes Mellitus and Tuberculosis

The fact that patients with diabetes mellitus easily acquire pulmonary tuberculosis is still true, despite the institution of insulin therapy. Of the wide variety of infectious diseases that the diabetic patient must guard against, the most serious is tuberculosis. According to some statistics, pulmonary tuberculosis ranks second only to coma as a complication of diabetes. It has been found also that pulmonary tuberculosis frequently occurs in diabetic patients following hyperglycemic coma. Of 748 diabetic patients seen at Bellevue Hospital by Ralli and Steinberg, 33 had active pulmonary tuberculosis, and in 29 of these the diabetes had preceded the tuberculosis. Himsworth found 15 cases (6.5 per cent) of pulmonary tuberculosis in 230 consecutive diabetic patients seen by him. In 13 of these the diagnosis was made by x-ray examination. From this he concluded that every diabetic patient should have a routine x-ray examination of his chest when first seen by his physician. It is believed by most observers that the reason for the diabetic patient's increased susceptibility to infectious diseases is his lowered resistance. Steinback, Klein and Deskowitz, in 1935, showed that following experimental removal of the pancreas, dogs lost their natural resistance to tuberculosis. For this reason it is felt that in the presence of diabetes, pulmonary tuberculosis shows special features. The exudative type of pulmonary tuberculosis is usually common in tuberculous diabetic patients. The lesions, pathologically, are large and confluent, and are infiltrations which tend to liquify extensively. This type of lesion is of uniformly bad prognostic import. The tuberculosis increases the severity of the diabetes and makes the latter disease more difficult to control. It was formerly thought that tuberculosis caused the death of no less than 40 to 50 per cent of diabetics, but extensive autopsy statistics have modified this figure to approximately 25 per cent.