DIABETES MELLITUS, AUTOIMMUNITY, AND AGEING

The prevalence of autoantibodies to gastric, thyroid, and nuclear antigens was measured in 400 diabetics, 200 being insulin-dependent and 200 non-insulin-dependent, and in 400 matched controls. A computer programme was used to determine the significance of positive or negative associations between pairs of attributes in diabetic patients, including autoimmune serological reactions, duration of diabetes, insulin dependence, age, sex, and associated diseases. Amongst the group of young patients with insulin-dependent diabetes of more than 20 years' duration the prevalences of thyrogastric autoantibodies, thyrogastric autoimmune disease, and vascular disease were increased. Moreover, insulin-dependent diabetics showed an unexpected decrease in the prevalence of thyrogastric autoantibodies with increasing age. This was attributed to a disproportionately high death-rate amongst diabetics with these autoantibodies. In long-term insulin-dependent diabetics under 40 years of age the prevalence of autoantibodies had already reached that found in controls over 60 years of age. Thus if the development of autoantibodies is an indication of ageing, it can be claimed that in certain insulin-dependent diabetics the ageing process is advanced by some 20 years over that in controls.