Requesting and Interpreting Urine Albumin Measurements in the Primary Health Care Setting

Abstract

The use of albumin measurement in urine as a marker of end-stage renal disease and cardiovascular disease (CVD) is well established, in particular for the diabetic population(1). Increased urine albumin is a predictor of renal failure, type 1 and type 2 diabetes, and cardiovascular events(2)(3)(4). It is now recognized that albuminuria reflects generalized vascular endothelial damage(5). The prevalence of diabetes, hypertension, obesity, and chronic kidney disease is rising markedly in many developing countries, and all of them contribute to cardiovascular disease. By 2020, it is predicted that 80% of the global burden of CVD will be borne by developing countries(6). The use of angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers may reduce microalbuminuria in individuals with and without diabetes, reduce progressive renal injury, and reduce cardiovascular events(7)(8)(9). These benefits appear to be partially independent of their antihypertensive effects. Control of dysglycemia and lipids, physical activity, and dietary protein restriction have been shown to reduce protein in urine and to have beneficial effects(8)(9)(10). Testing for albumin in urine has an identified role in secondary prevention, to establish treatment interventions and monitor progress and response to treatment. In primary prevention, it may have a role in reducing the burden of these chronic vascular diseases, but its practicality has not yet been fully defined by clinical studies. The measurement of albumin in urine is not standardized. The ongoing problems with analytical performance will probably continue to be an issue in the absence of both a reference material and a reference system for urine albumin measurement. Data from external quality assessment schemes show large between-laboratory and between-method variations for estimation …