Screening for microalbuminuria in the general population: a tool to detect subjects at risk for progressive renal failure in an early phase?

The number of patients taken into renal replacement therapy programmes has gradually increased over the last decades. This may partly be due to improvements in dialysis techniques and a better availability of these programmes. However, the pattern of the cause of end-stage renal failure also has been changing over time. In the 1970s glomerulonephritis and pyelonephritis were the most prevalent causes for enrolment into renal replacement programmes. In the last decade the prevalence of these diseases diminished and increasingly end-stage renal failure was due to diabetes, predominantly type II, and renal vascular diseases such as hypertension and generalized atherosclerosis. Several reasons have been put forward to explain this change. First, and possibly most important, the incidence of diseases has been changing. In addition, the age of patients entering end-stage renal failure programmes increased progressively, and patients with atherosclerotic cardiovascular disease survive cardiac events and reach the stage of atherosclerotic end-stage renal failure. Unfortunately, most of these patients are referred to the nephrologist only at a time when renal function is close to the level where dialysis is required, that is when not much can be expected of conservative renoprotective treatments. The purpose of this commentary is to hypothesize, on the basis of the existing evidence, what future options we have to predict, and thus possibly to prevent, the patient entering end-stage renal disease programmes. We will discuss first what factors are associated with progressive renal function loss in subjects with known renal diseases and secondly evaluate whether the data help us to detect subjects with progressive renal failure but without known renal disease in an early phase.