INCIDENCE OF CARDIOVASCULAR-DISEASE IN TYPE-1 (INSULIN-DEPENDENT) DIABETIC SUBJECTS WITH AND WITHOUT DIABETIC NEPHROPATHY IN FINLAND

This study evaluates the impact of diabetic nephropathy on the inciden ce of coronary heart disease, stroke and any cardiovascular disease in the Finnish population, which has a high risk of Type 1 (insulin-depe ndent) diabetes mellitus and cardiovascular disease. We performed a pr ospective analysis of the incidence of coronary heart disease, stroke and cardiovascular disease in all Type 1 subjects in the Finnish Type I diabetes mellitus register diagnosed before the age of 18 years betw een 1 January 1965 and 31 December 1979 nationwide. The effect of age at onset of diabetes, attained age at the end of follow-up, sex, diabe tes duration and of the presence of diabetic nephropathy on the risk f or cardiovascular disease was evaluated. Cases of nephropathy, coronar y heart disease, stroke and all cardiovascular diseases were ascertain ed from the nationwide Finnish Hospital Discharge Register and Nationa l Death Register using computer linkage with the Type I diabetes melli tus register. Of the 5148 Type 1 diabetic patients followed up, 159 ha d a cardiovascular event of which 58 were coronary heart diseases, 57 stroke events and 44 ether heart diseases. There were virtually no cas es of cardiovascular disease before 12 years diabetes duration. The cu mulative incidence of cardiovascular disease by the age of 40 years wa s 43 % in Type 1 diabetic patients with diabetic nephropathy, compared with 7% in patients without diabetic nephropathy, similarly in men an d women. The relative risk for Type 1 diabetic patients with diabetic nephropathy compared with patients without diabetic nephropathy was 10 .3 for coronary heart disease, 10.9 for stroke and 10.0 for any cardio vascular disease, similarly in men and women. The presence of nephropa thy in Type I diabetic subjects increases not only the risk of coronar y heart disease, but also of stroke by tenfold.