Current ICD definitions of malnutrition use biochemical markers as a component of the diagnostic criteria. Explain the effect of inflammation on visceral proteins and how that may impact the clinician's ability to diagnose malnutrition

Question

What laboratory values may confirm the presence of inflammation?

Answer 1

The body down-regulates albumin synthesis so that needed positive acute-phase proteins for the immune system (antibodies, complement, cytokines, C-reactive protein), clotting (fibrinogen), and wound healing can be made.
Production of cytokines such as IL-1, IL-6, and tumor necrosis factor (TNF) is increased, which alters hormone secretion to favor a catabolic state, increasing muscle catabolism, gluconeogenesis, and lipolysis. These cytokines also inhibit protein synthesis (albumin, prealbumin, transferrin, retinol-binding protein) and muscle repair.
Extracellular fluid is expanded (due to edema), causing biochemical tests to be diluted and results to appear low.
Resting energy expenditure is elevated/increased and protein requirements are increased, making energy and protein needs difficult to accurately determine.
If the cause of metabolic stress is severe or prolonged, nutrition intervention alone will not prevent muscle protein loss in inflammation if nutritional intake is inadequate. Therefore, measurement of albumin/ prealbumin is not an accurate measure for diagnosis of malnutrition when inflammation is present.