by Jessica Pyhtila, PharmD, BCPS, BCGP
It is common for people with diabetes to find out that they have protein in their urine. This condition, known as proteinuria, is a marker for kidney disease which can often occur in diabetes. For this reason, understanding what proteinuria is, and how to manage it, is very important for people with diabetes.
Albumin: the Body’s Major Protein
Albumin, a protein that is made in the liver, is one of the most important proteins in the body. It is also the most common protein, making up about 60% of all the body’s protein stores. Albumin plays many important roles, including:
· Stopping fluid from leaking out of blood vessels
· Providing nourishment to tissues
· Bringing vitamins, minerals and medications throughout the body
Albumin is needed for the proper function of all of the above. However, albumin levels are not set in stone. They can fluctuate based on your overall health and medical conditions. In particular, albumin levels can drop due to several different medical issues like:
· Leakage from the kidneys
· Liver problems, leading to less albumin being created
· Excessive protein breakdown in the body, which can occur during infections or injury
· Increased fluids in the bloodstream, which may occur if a person is in the hospital and needs IV fluids
Albumin and Kidney Disease
Normal, healthy kidneys conserve nutrients for the body instead of shedding them with other waste products in the urine. This includes proteins like albumin. However, when kidneys start to become damaged in kidney disease, proteins may start to spill into the urine. When this occurs, the resultant medical condition is proteinuria, also known as albuminuria.
Proteinuria Symptoms
The kinds of chronic kidney damage that are common in diabetes usually occurs slowly, over a long period of time. For this reason, there are often no symptoms of proteinuria during the early stages of the condition. However, remember that one of albumin’s main functions is to keep fluid inside the blood vessels where it belongs. As albumin levels drop due to proteinuria, fluid can start to leak out of the blood vessels and instead can accumulate in surrounding tissues. You may start to notice swelling when this occurs, especially in areas of the body like:
· Ankles
· Hands
· Stomach
· Face
Testing for Proteinuria
Because symptoms of proteinuria often only show up in the later stages of the condition, doctors will routinely screen for it during your regular health care visits. A urine test called a microalbumin creatinine test will tell your doctor if your urine contains protein or not. If you have Type 2 diabetes, experts recommend you get this test on an annual basis. If you have Type 1 diabetes, you should get the test every 5 years.
The test is usually conducted in one of two ways:
· Random urine sample: This is the test that is most often performed in doctor’s offices and labs. You obtain a cup and a cleansing pad for your genital area and urinate into the cup. The sterile urine can then be tested.
· 24-hour urine sample: In this test, you are given a container to take home. After emptying your bladder in the morning and flushing the first morning urine down the toilet, you then urinate into the container for the next 24 hours. The container must be refrigerated during this time. After the 24 hour period is over, you return the container to your health care provider.
Generally, the amount of protein, usually albumin, in your urine is compared against the amount of creatinine. Creatinine is a waste product in urine that your body releases at a steady rate. By comparing the ratio of albumin to creatinine, your doctor can tell how much protein is spilling into your urine. This test, called an albumin-to-creatinine ratio, or ACR, is calculated by dividing the milligrams of albumin in your urine by the grams of creatinine. The ACR will tell your doctor which stage of albuminuria you are in:
· ACR of less than 30: Category A1, meaning the albumin in your urine is normal to slightly increased
· ACR of 30 to 300: Category A2, meaning the albumin in your urine is moderately increased
· ACR of more than 300: Category A3, meaning there is severely increased albumin in your urine
· ACR of more than 2220: Nephrotic syndrome, with kidney damage characterized by symptoms like weight gain, fatigue, foamy urine and appetite loss
Generally, if your ACR shows concern for kidney damage, your doctor will refer you to a nephrologist, a type of doctor who specializes in kidney damage.
How to Stop Albuminuria
Unfortunately, kidney damage that has already occurred cannot be reversed. However, it is possible to maintain the health of your kidneys and slow further kidney damage.
Proteinuria often results from both increased blood sugar in people with diabetes, as well as high blood pressure, which is a common co-occurring condition in people with diabetes. For this reason, controlling both blood pressure and blood sugar are two of the best ways to keep your kidneys health. Some common types of medication your doctor may prescribe for albuminuria include:
· Angiotensin converting enzyme inhibitors, or ACEIs: This type of medication is taken by mouth. It is frequently used for cardiovascular conditions like high blood pressure and heart failure. In addition, it can help to slow down kidney damage. ACEIs include drugs ending in “-pril” like lisinopril (Prinivil, Zestril, Qbrelis) and ramipril (Altace).
· Angiotensin II receptor blockers, or ARBs: Like ACEIs, ARBs are taken by mouth. They are often used for cardiovascular conditions but are also recommended to slow down kidney damage. ARBs include drugs ending in “-sartan” like valsartan (Diovan) and candesartan (Atacand).
· Sodium-glucose Cotransporter-2 Inhibitors, or SGLT2is: This type of medication is taken by mouth. It is frequently used for blood sugar control in Type 2 diabetes and can also be used in heart failure. Further, SGLT2is have been shown to protect the kidneys. These medications typically end in “-gliflozin” like dapagliflozin (Farxiga) and empagliflozin (Jardiance).
· Glucagon-like Peptide-1 Receptor Agonists, or GLP1as: These medications are often used to control blood sugar in Type 2 diabetes and can also be used for weight loss. Their names typically end in “-glutide” and they include dulaglutide (Trulicity) and liraglutide (Saxenda, Victoza). Although they most often come as injectable medications, some, like semaglutide (Ozempic, Rybelsus) are also available in an oral formulation.
References:
LabTestsOnline. “Albumin.” July 24, 2020. Retrieved from: https://labtestsonline.org/tests/albumin
National Academies Press. “Infection and Injury: Effects on Whole Body Protein Metabolism.” The Role of Protein and Amino Acids in Sustaining and Enhancing Performance, 1999. Retrieved from: https://www.nap.edu/read/9620/chapter/12
U.S. National Library of Medicine. “Microalbumin Creatinine Ratio.” November 30, 2020. Retrieved from: https://medlineplus.gov/lab-tests/microalbumin-creatinine-ratio/
National Kidney Foundation. “ACR.” N.d. Retrieved from: https://www.kidney.org/kidneydisease/siemens_hcp_acr
National Institute of Diabetes and Digestive and Kidney Diseases. “Nephrotic Syndrome in Adults.” February 2014. Retrieved from: https://www.niddk.nih.gov/health-information/kidney-disease/nephrotic-syndrome-adultsAmerican Diabetes Association. “Microvascular Complications and Foot Care: Standards of Medical Care in Diabetes−2020.” Diabetes Care, January 2020. Retrieved from https://care.diabetesjournals.org/content/43/Supplement_1/S135
