Treating Abnormally High Level of Protein in the Urine

A quick overview of treatment strategies for treating proteinuria

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An essential tenet of treating high level of protein in the urine, or proteinuria, is treating its cause. The causes, as I discussed elsewhere could include chronic diseases like diabetes or hypertension, chronic infections like HIV or hepatitis, autoimmune diseases (eg. lupus), and even cancers. As you might imagine, the specific treatment for the multitude of these diseases will be different. However what I discuss below is the general treatment that all of these entities will require.

Finally, the following treatment is about all that we have when it comes to treating proteinuria that occurs from its most common causes, diabetes and hypertension.  

THINK BEYOND THE KIDNEYS

Excess protein in the urine does not just portend bad news for your kidneys. In fact, now it is also known to be a big risk factor for developing cardiovascular disease, putting you at risk of heart attacks, strokes, etc. 

WHAT HAPPENS IF YOU DON'T TREAT PROTEINURIA WITH THE ATTENTION THAT IT DESERVES?

As discussed here, untreated proteinuria makes you lose kidney function (GFR) faster, and worsens kidney disease. But just how bad is it? Well, there was a time when the renal prognosis for patients with proteinuria (for instance, from diseases like diabetes), was considered benign. However, this notion has long been dispelled, and now epidemiological evidence has given us some objective data. We now know that, left untreated, proteinuria, if severe, will cause end stage kidney disease (requiring dialysis/transplantation) in diseases like diabetes, in as little as six to seven years!

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.

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.

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 inhibitorseven if they don't have high blood pressure.

IS LOW PROTEIN DIET THE ANSWER

I have talked about the role of moderate protein diet in preventing CKD progression and in other forums as well. 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. 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 but going on a low protein diet may not be of benefit. 

A NOTE ABOUT SALT INTAKE 

For reasons beyond the scope of this article, 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.

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