THE ROLE OF DIABETES IN THE DEVELOPMENT OF DEGENERATIVE VASCULAR DISEASE: WITH SPECIAL REFERENCE TO THE INCIDENCE OF RETINITIS AND PERIPHERAL NEURITIS*

T H E advent of arteriosclerosis is one of the inevitable consequences of aging. The existence of arteriosclerosis in one or another part of the vas-cular tree after the age of 30 is to be expected. Its rate of progression and its predilection for certain special arterial channels are factors which influence profoundly the problem of longevity. It is apparent, also, that the anatomic distribution of the sclerotic process in relation to the arterial wall itself is an important consideration in determining the seriousness of the disease. Thus, the'intimal lesion affecting the medium-sized muscular arteries (coronary, cerebral and tibial) gains special prominence because of the likelihood of formation of secondary thrombi, with diminution and later obliteration of the lumens of such medium-sized muscular arteries. Neither the Monckeberg type of sclerosis nor, indeed, the intimal lesions of the larger elastic arteries possess the same potentialities for vascular occlusion. There are no doubt many factors which may influence the rate and extent of arteriosclerosis but our knowledge is, at best, inadequate to explain the phenomena which initiate arteriosclerosis or those which accelerate its prog-ress. The one factor which has received widespread consideration as a con-tributory cause to arteriosclerosis is diabetes mellitus. The recent survey of the incidence of coronary sclerosis among diabetic and nondiabetic patients carried out by Root, Bland, Gordon and White * again emphasizes this fact. The postinsulin era offers especially valuable subject material for analysis. Indeed, the introduction of insulin has created a fascinating biologic ex-periment, inasmuch as the diabetic patient now lives longer not only with his diabetes but also with his arteriosclerosis