Serum Creatinine vs. Albuminuria as Biomarkers for the Estimation of Cardiovascular Risk

Cardiovascular (CV) disease is the leading cause of morbidity and mortality among people with chronic kidney disease (CKD). CKD has increased over the past decade to become a worldwide public health problem. The definition of a biomarker is a characteristic objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic response to a therapeutic intervention. Thus, biomarkers of kidney function would include serum creatinine and more recently estimated glomerular filtration rate (eGFR). These biomarkers and microalbuminuria, potential biomarker, predict CV events and mortality. Recent analyses of cross-sectional data indicate that eGFR is a much stronger predictor of CV events than is microalbuminuria. While microalbuminuria indicates endothelial dysfunction and is associated with increased risk for CV events, its level is related more to the level of blood pressure and glycemic control than directly to the pathophysiology of atherosclerosis. Hence, microalbuminuria could be viewed as a biomarker but not a risk factor for CV risk since, risk factors must be an integral part of the disease pathophysiology. Conversely, while microalbuminuria is not of prognostic value to predict CKD outcomes, increases over time into the albuminuria range, >200 mg/day, clearly indicate presence of kidney disease and are associated with a more rapid decline in kidney function. Thus, concomitant evaluation of both biomarkers eGFR and albuminuria is recommended to assess kidney function and CV risk thoroughly.