Which statement best reflects malnutrition indicators in laboratory values?

• A. Decreased prealbumin and BUN
• B. Increased prealbumin and BUN
• C. Decreased bilirubin and ALT
• D. Normal albumin

Answer: (A)

In malnutrition, the body has limited protein intake and stores, so certain lab proteins change quickly while others stay relatively stable longer. Prealbumin (transthyretin) is a visceral protein with a short half-life, meaning it responds rapidly to changes in nutritional status. When someone is protein deficient, prealbumin levels drop promptly, signaling inadequate recent protein intake or absorption.

BUN reflects nitrogen coming from dietary protein to the liver for urea production. With insufficient protein intake or severely depleted protein stores, there is less substrate to form urea, so BUN levels tend to fall as well. So seeing both decreased prealbumin and decreased BUN together points toward protein-calorie malnutrition.

Other patterns don’t fit as well. An increased prealbumin would suggest adequate or improving protein status rather than malnutrition. A high BUN can occur with dehydration, high protein intake, or kidney dysfunction, not specifically with malnutrition. Bilirubin and ALT aren’t direct indicators of nutritional status; they relate more to liver injury or biliary problems. Albumin changes slowly and may remain normal in acute malnutrition, making it a less reliable early indicator.