THE INCIDENCE OF NEPHROPATHY IN TYPE-I DIABETIC-PATIENTS WITH PROLIFERATIVE RETINOPATHY - A 10-YEAR FOLLOW-UP-STUDY

Patients with type 1 diabetes mellitus and with proliferative retinopa thy often have a concomitant diabetic nephropathy. However, in cross-s ectional studies it has been shown that 35% of patients with prolifera tive retinopathy do not show signs of diabetic nephropathy. The aim of the present study was to examine the incidence of diabetic nephropath y in type 1 diabetic patients with proliferative retinopathy but witho ut signs of nephropathy. To that end, out of 102 consecutive patients with proliferative retinopathy attending the University Hospital, Lund , in 1986, 24 patients did not show any clinical signs of nephropathy, and were followed for 10 years regarding the development of nephropat hy. Their age was 36.7 +/- 9.8 years, age at onset 11.8 +/- 7.5 years, diabetes duration 25.7 +/- 6.9 years and duration of proliferative re tinopathy 4.6 +/- 3.8 years (mean +/- S.D.). At entry, no patient had albuminuria (< 30 mg/l), and albumin creatinine clearance ratio was < 0.01 x 10(-3). During the 10-year follow-up period, two of the patient s showed isolated higher peaks of elevated urinary albumin, but none o f the 24 patients developed persistent microalbuminuria (greater than or equal to 30 mg/l). Two patients died before follow-up, but none of: these had developed microalbuminuria at the time for death. Based on m ean annual measurements, there were no increases in HbA(1c), systolic and diastolic blood pressure, and serum creatinine levels. At entry, s even of the patients were treated with antihypertensive drugs and anot her three patients received such treatment during the study period. In conclusion, in a subgroup of patients with proliferative retinopathy, i.e. without clinical signs of diabetic nephropathy, no patient devel oped persistent microalbuminuria during a 10-year follow-up period. Th ese results indicate further evidence for at least partly different pa thogenic mechanisms behind diabetic retinopathy and nephropathy. (C) 1 998 Elsevier Science Ireland Ltd. All rights reserved.