7 Key Factors That Affect Albumin Status in End-Stage Renal Disease
At Vidafuel, we talk a lot about protein because we know what a big role it plays in healing wounds, fighting infections, and providing a great source of energy to the body!
If you missed our previous chats about albumin, take a quick look below at what it is and how we as clinicians can assess and improve other areas for albumin loss, including dietary intake.
What is Albumin?
Albumin is the most abundant protein in the blood that carries various substances throughout the body, including hormones, vitamins, and enzymes. It is made by the liver and helps keep fluid in the bloodstream so it does not leak into other tissues. A significant portion of the blood plasma, and the liquid portion of the blood that holds the protein and blood cells is made up of albumin.³
Hypoalbuminemia is a medical sign in which the level of albumin in the blood drops below normal levels.
7 Key Factors That Affect Albumin Status in End-Stage Renal Disease
Kidney damage can cause protein to be released in the urine. This takes albumin from the blood, causing hypoalbuminemia.
Several key factors can also cause albumin to be decreased in the blood, including:
Fluid overload, or hypervolemia, is a condition in which you have too much fluid in your body. This increase in fluid can cause high blood pressure, swelling, and heart problems. Hypovolemia is especially threatening for patients with chronic kidney disease because their kidneys cannot excrete the excess water the same way healthy kidneys would. Proteins in the blood tend to pull water into our blood vessels (acting like a "water magnet"). When the level of protein in the blood is low, water may leave the blood vessels and collect in the tissues (edema). Edema can be developed in critically ill patients for many reasons, hypoalbuminemia being one of them.²
Renal dietitian tip: Educate patients on the importance of a low sodium diet (1500-2000mg/day) along with a fluid restriction that is specific to them. Ensuring patients know their dry weight (or edema-free weight) is also an important tool to keep them on track between treatments!
Dialysis removes many waste products from the blood, urea being the most abundant. If a patient misses treatment or reduces their time on the dialysis machine, the waste products in their blood will not be thoroughly cleansed. Inadequate dialysis results in a decreased appetite/PO intake, altered taste, nausea, weight loss, more frequent hospitalizations and higher mortality rates. All of these factors lead to a decline in albumin.
Renal dietitian tip: Advise patients to attend all dialysis treatments for prescribed time and make sure their access site is working efficiently to prevent hypoalbuminemia.
Metabolic acidosis is a condition in which the body’s acid content is too high to support good health. In order to detect the body’s acid level, a test that measures carbon dioxide that is dissolved in the blood (serum bicarbonate) is conducted. Bicarbonate is a base and helps maintain the body’s acid-base balance. Healthy kidneys remove acid from the body through urine, but patients with CKD cannot do this effectively thus leading to metabolic acidosis. Normal levels of serum bicarbonate are 22-29mEq/L.9 If a patient's levels drop below 22mEq/L they will be in metabolic acidosis. Metabolic acidosis stimulates protein catabolism and decreases protein synthesis, thus leading to hypoalbuminemia.¹
Renal dietitian tip: Check patients CO2 lab value to ensure it is within the 22-29mEq/L range. If their lab value drops below 22, notify your charge nurse as the patient will be in metabolic acidosis and at risk for hypoalbuminemia.
Vitamin D 25(OH) Deficiency
The Clinical Journal of the American Society of Nephrology conducted a study on Vitamin D deficiency in dialysis patients and found that low serum albumin levels are associated with increased risk of vitamin D deficiency.⁶ Vitamin D is poorly soluble in water and must be transported via the blood bound to proteins such as Vitamin D-binding protein and albumin. Hypoalbuminemia could reduce the carrying capacity for Vitamin D and hinder its ability to be delivered to the tissues.⁷
Vitamin D deficiency can be dangerous for renal patients. It’s most important role in the body is the maintenance of bone health, and it’s ability to increase absorption of calcium to maintain strong bones. Healthy kidneys convert vitamin D from supplements and the sun into its active form. This helps keep phosphorus and calcium balanced in the body by controlling absorption of these minerals from our food and regulating parathyroid hormone (PTH).
In CKD/ESRD the kidneys cannot perform this function properly. Without activated vitamin D to control calcium and phosphorus levels in the blood, PTH will try to overcompensate and go out of range. Chronic hyperparathyroidism puts the patient at risk for developing osteoporosis, and overall bone and joint pain.
Renal dietitian tip: Check vitamin D levels and adjust active Vitamin D (Hectorol/Calcitriol) doses appropriately. Educate patients on the importance of taking their binders with meals and monitoring their calcium/phosphorus intake.
Factors to consider when patients are hospitalized include: weight loss, poor PO intake, and changes in living situations that lead to lack of protein intake. When patients are unable to consume adequate oral intake due to feeling unwell or being on an NPO diet, for instance, their decreased intake of protein can lead to overall body protein loss which will in turn lead to decreased albumin levels. Serum albumin level is an important prognostic indicator, which can be used to estimate the chance of recovery or recurrence from a disease. Among hospitalized patients, lower serum albumin levels correlate with an increased risk of morbidity and mortality.⁴
Renal dietitian tip: Upon discharge, check the status of your patients living situation and if they have had any changes in access to food. Monitoring weight loss after a hospitalization stay is very important to determine a proper dry weight.
Download our hospitalization passport to share with your renal patients in order to help them track important health information!
Infection and Inflammation
Inflammation and infection can suppress albumin synthesis in the liver leading to hypoalbuminemia. Dialysis vascular access infections, gum disease, poor dental health, foot ulcers, uremia or poor functioning transplanted kidneys are other inflammatory factors for people with CKD/ESRD. Many of these factors as well as others lead to inflammation which causes an increased vascular permeability which allows albumin to diffuse into the extravascular space.
Other causes of low albumin due to inflammation include:
- Bladder infections
- Antibiotic therapy for acute infection
- Chronic diseases such as: lupus, arthritis, CKD, cancer, diabetes, cardiovascular disease, IBD, autoimmune disease, periodontal disease
Renal dietitian tip: Check in with your patients with hypoalbuminemia to see if they have any of these underlying conditions.
Malnutrition also suppresses albumin synthesis in the liver. Clinicians can check patients for the following to help albumin:
- Diet/overall protein and calorie intake
- Checking appropriate diet order for extracellular fluid (ECF)
- Dysphagia evaluation
Protein recommendations based on patients lab values and comorbidities
Indications for treatment such as ONS, enteral nutrition and IDPN.
Renal dietitian tip: Educate patients on vitamin D and protein rich foods to help increase their albumin through diet as appropriate.
It is clear that there are a variety of factors that influence albumin status beyond appetite. In order to assess the patient's overall health it is important to remember the underlying conditions that could be contributing to hypoalbuminemia.
Brady JP, Hasbargen JA. Correction of metabolic acidosis and its effect on albumin in chronic hemodialysis patients.
Albumin and Edema. LHSC.
MediLexicon International. Hypoalbuminemia: Causes, treatment, and symptoms. Medical News Today. https://www.medicalnewstoday.com/articles/321149
Ruben Peralta, M. D. Hypoalbuminemia. Background, Pathophysiology, Etiology.
Inflammation and chronic kidney disease. DaVita.
- Ishir Bhan, Sherri-Ann M. Burnett-Bowie, Jun Ye, Marcello Tonelli, Ravi Thadhani. Clinical Measures Identify Vitamin D Deficiency in Dialysis.
Bikle, D.D., Vitamin D Insufficiency/Deficiency in Gastrointestinal Disorders.
Facts about Metabolic Acidosis and Chronic Kidney Disease. National Kidney Foundation.
Colombo J. A Commentary on Albumin in Acidosis.