Is proteinuria a marker and a target of disease activity in progressive kidney disease
Can proteinuria be used as a marker and a target of disease activity in the person with progressive kidney disease? If so How?
Proteinuria is an important surrogate outcome for disease activity in someone with progressive kidney disease. In a patient with glomerular kidney disease, the level of proteinuria correlates with disease activity and potential risk for progression.
Therefore therapeutic decisions aimed at lowering protein excretion should be implemented in a paradigm similar to BP management; baseline protein excretion should be estimated using a urine test such as the urine protein-to-creatinine ratio.
The urine protein-to-creatinine ratio roughly approximates the amount of protein a patient excretes in a single 24-hour period. A lower value of approximately 0.3 g or less is considered normal. A value >0.3 g is abnormal.
In a patient with an abnormal level of proteinuria, therapy, such as ACE inhibitors or ARBs, should be initiated to lower urine protein excretion. The urine protein excretion should be rechecked to determine the effect of therapy. The therapeutic goal is to decrease the urine protein-to-creatinine ratio to the lowest value possible.
If, after initiating the therapy, the desired urine protein-to-creatinine ratio is not reached, the medication chosen should be titrated up as tolerated.
However, patients should not be treated with a combination of both ACE inhibitors and ARBs or a combination of ACEi and direct renin inhibitors because studies have shown that these drugs in combination are associated with an increased risk of adverse events and a more rapid decline in GFR, despite effectively lowering proteinuria.
