Proteinuria refers to a condition where there is protein in the urine. It could be a sign of kidney disease.
Usually, the kidneys remove waste products from our blood and take them out of our body via urine. But the kidneys do not allow important substances, like protein, to escape into the urine. So, protein in the urine may indicate that the kidney filters are not working.
Protein in the urine may not only be a sign of kidney disease but can also cause further damage. This is why doctors test for proteinuria.
When present, your doctors will try to figure out what’s causing it. By learning what’s behind proteinuria, doctors can help you take steps to treat it and take care of your kidneys.
This blog post will give insights into how your healthcare team handles proteinuria.
Types of proteinuria
There are different kinds of proteinuria with different implications.
Orthostatic proteinuria: This is when protein is only found in your urine when you’re in the upright position. This is more common in young people and is not usually something to worry about.
Transient proteinuria: This is when proteinuria occurs temporarily following an event like exercise or fever.
Persistent proteinuria: Further investigations are warranted to determine the cause of persistent proteinuria. As the name suggests, this condition occurs when protein consistently appears in urine. Kidney disease, like nephrotic syndrome, could cause persistent proteinuria.
Alternatively, persistent proteinuria may be overflow proteinuria that occurs when there’s too much protein in the blood. For example, diseases like multiple myeloma cause the production of excessive amounts of a type of protein, and this can lead to an overflow of protein into the urine. Overflow proteinuria can lead to kidney damage because protein in urine is toxic to the kidneys.
Testing for proteinuria
Healthcare professionals test for proteinuria using different methods.
A dipstick urinalysis strip is usually the initial test for protein. It provides results as trace, +, 2+, 3+ etc. It does not provide the exact quantity of protein in the urine. If dipstick testing persistently detects protein in urine, doctors may attempt to quantify urine protein using additional tests.
24-hour urine protein measures how much protein is present in urine over 24 hours. This involves collecting all urine produced in the 24 hours being studied. As you can imagine, this method is cumbersome.
Urine protein creatinine ratio is another method for quantifying protein in urine. This method may use a random urine sample, an early morning urine sample, or a short-timed urine sample like 4 hours. The results estimate urine protein in 24 hours because the result is standardized by measuring creatinine levels.
Clinical significance
It is an indicator of kidney disease and is also associated with progressive worsening of kidney disease. If two patients have stage 3 chronic kidney disease, the patient with massive proteinuria will likely decline faster to end-stage disease than the patient without proteinuria. This is why healthcare practitioners are worried about proteinuria and try to treat it aggressively if present.
Furthermore, even people with other health conditions (besides kidney disease) have worse outcomes when they have proteinuria.
Treatment of proteinuria
Lifestyle modification is one of the first changes recommended. Such interventions include a low salt diet, blood pressure control, and limiting protein intake. This does not mean completely removing proteins from your diet. Remember, it is an essential macro-nutrient needed for body function and repairs.
Drugs: Several drugs help with proteinuria. The angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are one of the most common drugs used to reduce proteinuria, and they have been shown to protect the kidneys.
In recent times the sodium-glucose cotransporter2 inhibitors used to treat diabetes have also been shown to help with chronic kidney disease associated with proteinuria, not just in people with diabetes but also in those without diabetes.
Bottom line
Proteinuria is a condition where there’s too much protein in the urine, and it’s a vital sign that something might be wrong with the kidneys. This can happen because of diseases or issues that let the proteins pass through the kidney filters.
But not all cases of proteinuria are a big deal. Sometimes, especially in young people, non-serious proteinuria, like orthostatic proteinuria, may occur.
Your healthcare team will investigate to determine the cause of your proteinuria. This way, you can take action and improve your outcome. Early interventions can make a big difference.