How do you treat excess protein in the urine (proteinuria)?
I had covered why excess protein in the urine needs to be treated in my earlier post. Lets talk briefly about how we go about achieving that.
Before I discuss the treatment strategies, let me reiterate that minimizing protein that you lose in the urine or proteinuria is an essential goal of treatment of chronic kidney disease (CKD) because if left untreated, it increases the risk of progression to kidney failure. In diseases like diabetes, severe untreated proteinuria will typically cause kidney failure in as little as six to seven years.
DRUGS THAT TREAT PROTEINURIA
Most of the medications that we use to treat proteinuria are actually blood pressure medications, although not all blood pressure medications will treat proteinuria. These medications include the commonly used ACE inhibitors (eg. lisinopril, enalapril, etc), and ARBs (eg. losartan, irbesartan, etc). There used to be a time when their effect was considered additive, but now it is no longer recommended that ACE inhibitors and ARBs be used together given the increased risk of adverse effects.
Multiple medical studies have proved that worsening of kidney disease can be prevented if proteinuria is treated using specific drugs like ACE inhibitors or ARBs. Interestingly, the protective effect that comes with these medications is independent of the control in blood pressure induced by the drugs! A greater reduction translates in to more kidney protection, and a more favorable outcome for your kidneys.
Another class of blood pressure reducing drugs that could have a similar efficacy in treating proteinuria are called non-dihydropyridine calcium channel blockers. The examples include drugs like verapamil and diltiazem, and their effects may be additive to ACE/ARBs. Finally, we have a diuretic called spironolactone that also could be beneficial in this setting.
|Image courtesy of Witthaya Phonsawat/ FreeDigitalPhotos.net|
A NOTE ABOUT SALT INTAKE
For reasons beyond the scope of this blog, I do want to emphasize that high salt intake makes proteinuria worse. It also blunts the protective effects of ACE inhibitors or ARBs. Ipso facto, it makes sense to consume a low salt diet to further minimize your proteinuria. We have clear medical evidence that supports this approach as well.
SHOULD YOU RESTRICT YOUR PROTEIN INTAKE?
Even though it makes intuitive sense, and even though excess protein in the urine is directly associated with hyperfiltration, at this time the effect of protein restriction (especially when it is done in combination with ACE inhibitors or ARBs) on renal function is uncertain. I have discussed those issues in more detail in another post. For now, lets just suffice it to say that a moderate protein diet with about 0.8 grams per kilo body weight of protein per day, might be beneficial.
WHAT IF YOU DON'T HAVE HIGH BLOOD PRESSURE (BUT DO HAVE PROTEINURIA)?
You might have noticed that the medications that I mentioned above are all blood pressure reducing medications. The above question hence often comes up in people who just have proteinuria but no hypertension. Is it safe for them to take these medications? Some studies have tried to answer this question, and it appears that as long as someone is not experiencing side effects or low blood pressure as a result, it may be beneficial for people with proteinuria to take medications like ACE inhibitors, even if they don't have high blood pressure.
Bradenton / Sarasota / Lakewood Ranch, FL