Background: In all Western countries there is a dramatic increase of diabetic patients who need renal replacement therapy. Very different figures for incidence and prevalence have been reported. There is a strong suspicion that the epidemiological dimension of the problem has been underestimated in many of the statistics.
Methods: In a retrospective analysis we assessed all patients admitted to the Department Internal Medicine Heidelberg from January 1(st) 1998 - December 31(st), 2000 for renal replacement therapy, i. e. hemodialysis or CAPD, because of acute or chronic renal failure. We counted the number of known diabetic patients (i) with signs of classical diabetic nephropathy (enlarged kidneys, proteinuria > 1g/24h +/- retinopathy), (ii) with atypical renal changes (contracted kidneys, proteinuria < 1 g/24 h) and (iii) diabetic patients with (coincident) primary chronic renal disease as well as (iv) the proportion of patients in whom the diagnosis of diabetes had been unknown when uremia had supervened.
Results: Dialysis treatment was started in 568 patients for acute (ARF; n = 341) or chronic (CRF; n = 227) renal failure. 95/341 (28 %) patients with ARF had diabetes. ARF occured in no less than 12/95 (13 %) of the diabetic patients after cardiological intervention. Diabetes was present in 111/227 patients with CRF (7 type 1, 104 type 2); in 12/111 patients the diagnosis of diabetes was established only after admission. Only 67/111 of the diabetic patients (60 %) had classical signs of diabetic nephropathy, in 14/111 (13 %) patients the classical signs of diabetic nephropathy were absent and in 30/111 (27 %) non-diabetic primary chronic renal disease was present.
Conclusion: The study illustrates the importance of diabetes for the epidemiology of renal failure. A sizeable proportion of patients with acute renal failure have diabetes, typically patients with pre-existing nephropathy in whom this complication supervenes during diagnosis and treatment of late diabetic complications. In diabetic patients with chronic renal failure the presentation is frequently atypical and non-diabetic primary renal disease is present more frequently than expected by chance. In a sizeable proportion of patients diabetes had not been diagnosed by the time chronic renal failure occurred.