1. BACKGROUND Diabetic nephropathy develops in as many as 25-40% of diabetic patients after 25 years of diabetes. This makes diabetic nephropathy the most common cause of end-stage renal disease (ESRD) in the western world (9) where it accounts for approximately 22% of patients starting dialysis in Denmark (10) and 44% in the US (11). Diabetic nephropathy is characterised clinically by the occurrence of albuminuria, elevated blood pressure and a progressive decline in kidney function (9) and is associated with a marked increase in cardiovascular morbidity (12) and mortality (13). Before the introduction of renoprotective treatment, the median survival was 5-7 years after the onset of persistent albuminuria (9). However, within the last 25 years, intensive research has dramatically improved the treatment and thereby prognosis in diabetic nephropathy, as reviewed by Parving et al (14). A recent paper reported a median survival of more than 21 years from the onset of diabetic nephropathy in type 1 diabetic patients, mainly due to good blood pressure control (15) and decline in the incidence of ESRD has been reported in type 1 diabetic patients (16). Similar long-term observational data on survival in type 2 diabetic patients with diabetic nephropathy are not available, however it has been shown that reductions in proteinuria/albuminuria are associated with reduced risk for ESRD (17) and cardiovascular morbidity (18) and associated with improved survival (19) in type 2 diabetic patients. Despite improvement in the prognosis large interindividual differences in response to therapy exist, thus the renoprotective effect is not complete and there are still patients with unacceptable fast disease progression. Therefore evaluations of