Which of the following lab results helps evaluate kidney function?

BUN, or blood urea nitrogen, is an important laboratory test used to assess kidney function. The kidneys play a crucial role in filtering waste products from the blood, and urea is one such waste product formed from the breakdown of proteins. In healthy individuals, the kidneys efficiently remove urea from the bloodstream, which keeps BUN levels within a normal range.

When kidney function is compromised, such as in conditions like acute or chronic kidney disease, the ability to filter out urea diminishes, leading to elevated BUN levels. Therefore, measuring BUN provides valuable information regarding the kidneys' excretory capacity and overall function, making it a key marker in assessing renal health.

The other options listed do not specifically serve as indicators of kidney function. ALT and AST are liver enzymes that help evaluate liver function, while albumin is a protein that, although it can provide some information regarding kidney function, primarily indicates nutritional status and the body's ability to synthesize proteins. Thus, BUN is the most direct indicator for evaluating kidney function among the options provided.