The pattern and behavior of pulmonary tuberculosis in diabetic patients.

betes mellitus and pulmonary tuberculosis has long been observed. Moreover, the incidence of tuberculosis in diabetics is more than in the general population. Windle,' in a study of 333 necropsies of diabetics, gave an incidence of pulmonary tuberculosis in 50 per cent. Himsworth' reported an incidence of 6.5 per cent pulmonary tuberculosis in routine x-ray films. Root3 stated that in children and young people, tuberculosis occurs about 12 times as frequently among diabetics as in non-diabetics. Boucot and associates4 found a prevalence of pulmonary tuberculosis of 8.4 per cent among 3,106 diabetic patients in Philadelphia, which was twice as high as the prevalence in a group of apparently healthy industrial workers. The variability of these figures is in all probability due to the differences in material and age groups. The exact reason for such a high incidence of tuberculosis in diabetics is not known and only few suggestions have been made. Dubos5 quotes experimental evidence that ketosis is the most important factor in starvation which causes activation of the tuberculous foci; it seems reasonable to infer that this may be the case in diabetes. Banyai6 attributes this susceptibility to overproduction of A.C.T.H. with resultant lowered bacteriostatic capacity and deficiency in tissue repair, as well as to hepatic dysfunction with vitamin A deficiency which probably account for the high incidence of the exudative forms of tuberculosis in these patients. Poulsen7 considers overproduction of glycerol in diabetics to be a good source of energy for tubercie bacilli. Root3 stated that the cells of the reticuloendothelial system of patients dying in diabetic coma are completely filled with lipids which interfere with the immuno-biologic reaction against infection. This study is confined to the pattern of the tuberculous lesion (type, extent and location) encountered in diabetic patients as well as its behavior on treatment. OBSERVATIONS The total number of diabetics reviewed is 371 with bronchogenic tuberculosis, in all of whom a bacteriologic diagnosis was made. Only cases observed for a minimum of two years from the time of diagnosis of tuberculosis were included. The cases were treated from 1954 until 1960. There were 290 men and 81 women. The age range varied from 22 to 75, while only 19 cases were below the age of 45 years. Characteristics of Diabetes Diabetes was known to exist before tuberculosis in 280 cases (75 per cent) while both tuberculosis and diabetes were diagnosed simultaneously in 91 cases (25 …