Hypoalbuminemia and Clinical Outcomes: What is the Mechanism behind the Relationship?

Abstract

Albumin has a number of important physiologic functions, which include maintaining oncotic pressure, transporting various agents (fatty acids, bile acids, cholesterol, metal ions, and drugs), scavenging free oxygen radicals, acting as an antioxidant, and exerting an antiplatelet effect. Hypoalbuminemia in adults, defined by an intravascular albumin level of <3.5 g/dL, is associated with poor postoperative outcomes in patients undergoing surgical intervention. Although the relationship of hypoalbuminemia and poor surgical outcome has been known for many years, the pathophysiology behind the relationship is unclear. Three theoretical constructs might explain this relationship. First, albumin might serve as a nutritional marker, such that hypoalbuminemia represents poor nutritional status in patients who go on to experience poor postoperative outcomes. Second, albumin has its own pharmacologic characteristics as an antioxidant or transporter, and therefore, the lack of albumin might result in a deficiency of those functions, resulting in poor postoperative outcomes. Or third, albumin is known to be a negative acute phase protein, and as such hypoalbuminemia might represent an increased inflammatory status of the patient, potentially leading to poor outcomes. A thorough review of the literature reveals the fallacy of these arguments and fails to show a direct cause and effect between low albumin levels per se and adverse outcomes. Interventions designed solely to correct preoperative hypoalbuminemia, in particular intravenous albumin infusion, do little to change the patient's course of hospitalization. While surgeons may use albumin levels on admission for their prognostic value, they should avoid therapeutic strategies whose main endpoint is correction of this abnormality.

Morbidity, mortality and temporal trends in the surgical management of retroperitoneal sarcoma: An ACS‐NSQIP follow up analysis

“…In addition, the use of MVR was not associated with worse overall or severe morbidity on multivariate analyses. Instead, we observed that other variables typically associated with a greater risk of surgical complications, such as malnutrition (hypoalbuminemia) and tumor size >10 cm, were significant predictors of surgical complications following RPS resection in our analysis. Although retrospective in nature, these data provide further evidence suggesting that MVR for RPS can be performed with acceptable morbidity and mortality, including at a cross‐section of NSQIP hospitals.…”

Association between nutritional risk index and outcomes for head and neck cancer patients receiving concurrent chemo‐radiotherapy

“…Low albumin in oncology patients is often due to increased capillary membrane permeability, lack of protein intake, and systemic inflammatory state (negative acute phase protein). [26][27][28] Albumin is responsible for physiologic functions such as oncotic pressure maintenance and fatty acid, toxin, and drug transport. 25,26 However, it is unclear whether low albumin is the cause or indicator of systemic process associated with poor outcomes.…”

A Study of the Prognostic Significance of Serum Albumin Levels in Myelodysplastic Syndrome

“…The pathophysiology involves various cytogenetic changes with gene mutations with widespread hypomethylations in the genome. 1,2 The clinical manifestations result from various combination of cytopenias-anaemias, leucopenias and thrombo-cytopenias. Diagnosis involves peripheral blood examination and bone marrow examinations showing a variety of changes in the different subtypes of myelodysplastic syndrome ranging from cytopenias to hyperproliferation with dysplasias and variable amount of blast cells.…”

“…2,3 The mechanism postulated for low serum albumin in inflammation is by various cytokines like TNF, IL-6, causing high vascular permeability, high albumin degradation and TNF alpha mediated downregulation of albumin gene transcription. 2 Decrease in serum albumin in various medical conditions by as low as 10 g/L causes mortality to increase by 137% and morbidity by 89%. The exact mechanism that causes low serum albumin to cause high mortality and morbidity is unknown.…”

“…That is low serum albumin represents high inflammatory states. 2,3 Various prognostic indicators used in previous studies in myelodysplastic syndrome include clinical factors like age, gender, comorbidities and laboratory variables like haemoglobin levels, serum albumin, red cell distribution width, mean corpuscular volume, serum ferritin and lactate dehydrogenase. 4,5,6,7,8,9 Multiple studies from the west have shown serum albumin levels at presentation to correlate well with prognosis of patients.…”