Which marker best reflects hepatic synthetic function?

• A. Albumin
• B. Bilirubin
• C. Ammonia
• D. AST

Answer: (A)

The main idea here is what the liver produces in its role as a metabolic factory. Albumin is a major protein made by hepatocytes and serves as a direct measure of the liver’s ability to synthesize proteins. When the liver’s synthetic function is impaired, albumin levels fall, which is why low albumin is a classic marker of reduced hepatic production capacity and can indicate chronic liver disease or malnutrition related to liver dysfunction.

Bilirubin reflects how well the liver handles processing and excreting bile pigments, not its protein-making ability. Ammonia levels rise when the liver can’t effectively detoxify or convert ammonia to urea, but this speaks to detoxification rather than synthesis. AST is a liver enzyme that rises with hepatocellular injury, indicating damage to liver cells rather than how well the liver can synthesize proteins.

So albumin best reflects hepatic synthetic function because it directly measures the liver’s capacity to produce a key plasma protein.