Mortality and Causes of Death among Japanese Diabetics with Diabetic Neuropathy, Retinopathy and Nephropathy

A Prospective Follow-up Study for Three Years

Abstract

A few prospective follow-up studies have described the mortality and causes of death among Japanese diabetics with diabetic microangiopathies. To clarify the prognosis of Japanese diabetics, we undertook a prospective follow-up study of 1, 629 diabetic patients (898 males, 731 females) who visited our Diabetes Center in 1976. In this paper, we describe the results of a three-year follow-up study, especially regarding the mortality and causes of death among the patients with diabetic neuropathy, retinopathy and nephropathy.
During this follow-up study, only three cases dropped out within three years from the start. The deaths of 106 cases (78 males, 28 females) were confirmed at the end of the three-year follow-up. We obtained death certificates for all the deceased patients.
Although the cumulative death rate after the three-year follow-up among the 1, 629 diabetics (all cases) was 6.5%, that among 864 patients with diabetic neuropathy at registration was 8.1%. That among 139 with proliferative retinopathy and that among 139 with severe proteinuria (+++ and more) were 10.1% and 21.1%, respectively.
Whereas the cumulative death rate after the three-year follow-up among 202 diabetics with all of neuropathy, retinopathy and nephropathy (proteinuria) at registration was as high as 13.4%, that among 401 patients with none of these three diabetic microangiopathies was as low as 2.5%. The main causes of death among the patients who had had diabetic triopaties at registration were diabetic nephropathy and ischemic heart disease. On the other hand, those among patients with none of these three diabetic microangiopathies were malignant neoplasms.