Implications of proteinuria: CKD progression and cardiovascular outcomes.

In this review, we summarize the evidence for the associations of proteinuria with incident CKD, progression of kidney disease, development of kidney failure, as well as the association with surrogates of cardiovascular disease (CVD), clinical cardiovascular outcomes, and all-cause mortality. Results reveal that proteinuria is a powerful and independent risk factor for kidney and cardiovascular outcomes, and that these relationships are independent of the level of glomerular filtration rate. Furthermore, these associations are true in populations at high, medium, and low risk for kidney disease progression and development of CVD. We show data which demonstrate that the associations with CVD are present even at levels of proteinuria below current cutoffs for microalbuminuria, and that changes in proteinuria may be a useful predictor of future outcomes. Finally, we provide some theories as to why proteinuria may be a risk factor for development of CVD.