[Clinicopathological study of diabetic nephropathy in the elderly]

We studied the relationship between clinical characteristics and renal structural changes in 29 elderly patients in whom non-insulin-dependent diabetes mellitus was diagnosed when they were 60 years of age or older. The clinical stage of nephropathy was graded according to the criteria of the Ministry of Health and Welfare of Japan: stage 1 (12 patients), normoalbuminuria; stage 2 (11 patients), microalbuminuria; stage 3 (1 patient), persistent proteinuria; stage 4 (5 patients), chronic renal failure. Renal biopsy specimens were semiquantitatively evaluated with regard to diffuse glomerular lesions, nodular lesions, and vascular lesions. In patients at stage 1, minimal-to-moderate diffuse lesions were observed, and vascular lesions were already present. In patients at stage 2, various alterations in diffuse lesions were observed and were associated with prominent changes in the vascular lesions. More advanced changes in the diffuse and vascular lesions were noted in patients at stages 3 and 4, but nodular lesions were found in only one patient. These patients had a high incidence of hypertension and ischemic heart disease. We conclude that elderly diabetic patients with nephropathy of different clinical stages have different underlying diabetic renal lesions.