Which laboratory value change is associated with kidney disease?

Serum creatinine is a key indicator of kidney function. In the context of kidney disease, an increase in serum creatinine levels signifies the kidneys' diminished ability to filter waste and maintain homeostasis. A serum creatinine level greater than 4 mg/dL indicates severely compromised kidney function, often suggesting conditions such as acute kidney injury or chronic kidney disease. Maintaining normal creatinine levels is crucial, as significant elevations can reflect the degree of renal impairment.

While changes in other lab values can occur in various conditions, they do not specifically correlate as directly with kidney function. For example, serum albumin levels can be affected by a range of factors, including liver function and nutritional status, but do not directly indicate kidney disease alone. Similarly, elevated serum sodium levels and low serum calcium levels can occur due to numerous other conditions unrelated to kidney disease. Thus, a serum creatinine level exceeding 4 mg/dL is the most definitive indicator of serious kidney dysfunction among the choices provided.