As we discussed earlier, proteinuria is a major complication of chronic kidney disease. It results from the inability of damaged nephrons to properly filter blood, causing essential proteins to leak into urine. The first line of defense in antiproteinuric management, is using two antihypertensive medications discussed in the previous section, ACE (angiotensin-converting enzyme) inhibitors and ARBs (angiotensin-receptor blockers). As we know, both ACE inhibitors and ARBs work by blocking the effects of angiotensin II, an enzyme that causes our blood vessels to tighten. The result of this blockage is the widening of our blood vessels to decrease pressure and increase blood flow.
Not only do ACE inhibitors and ARBs work by reducing blood pressure in the overall body, it also reduces the blood pressure in the smallest vessels of our kidneys. When there is less blood pressure within the glomerulus, there is less force exerted against the vessel. As a result, fewer proteins are pushed out of the glomerulus, which causes fewer proteins to be excreted in the urine and instead remain in the body.
As we mentioned in previous sections, kidney disease causes a loss of nephron function. As a result, the kidneys cannot excrete excess potassium that can lead to a buildup within the body. It is important to note that when taking antihypertensive medications like ACE inhibitors and ARBs, the risk of experiencing hyperkalemia is greater. It is therefore essential that you monitor your potassium levels and maintain a low potassium diet. It is also important to continue to take your diuretic medication as prescribed to promote excretion of excess potassium through the urine.
In normal kidney function, waste products such as urea and uric acid are normally excreted in the urine. Uric acid is a waste product that forms from the breakdown of purines, a natural substance found in our diet and proteins. As our kidney function declines, our ability to remove urea and uric acid from the body, malfunction. This can lead to serious complications such as hyperuricemia. Hyperuricemia is a condition that occurs when the uric acid levels in your blood are too high because the uric acid is not released as waste. Patients can manage high levels of urea in the blood by taking medication or by dialysis, which will be discussed in the next section.