Albumin

Albumin is the principal soluble protein in human plasma, synthesized mainly by the liver. It helps maintain plasma colloid osmotic pressure and transports a range of endogenous and exogenous substances, including fatty acids, hormones, metabolites, and some medicines. Serum albumin concentration is therefore influenced by hepatic synthesis, nutritional and inflammatory states, fluid balance, and protein loss, and is commonly interpreted as a clinical marker rather than as an isolated measure of nutritional status.

In the literature represented here, albumin is used in nutritional, inflammatory, renal, infectious, and oncological risk assessment. It contributes to composite measures such as the albumin-derived neutrophil-to-lymphocyte ratio, geriatric nutritional risk index, prognostic nutritional index, and C-reactive protein/albumin ratio, and is incorporated with body mass index, hemoglobin, creatinine, C-reactive protein, and neutrophil-to-lymphocyte ratio in prognostic or predictive models. Reported applications include associations with survival in colorectal cancer, oral squamous cell carcinoma, lymphoma, and extensive-stage small-cell lung cancer; renal progression in type 2 diabetes; infection risk in systemic lupus erythematosus; and clinical outcomes in ulcerative colitis. Albumin-to-creatinine ratio is a related urinary measure used to assess albumin excretion and its relationship to glycemic control, and should be distinguished from the serum albumin concentration.