A common age-related change in the kidneys is a lower glomerular filtration rate. Which option best describes this?

• A. Normal GFR
• B. Increased GFR
• C. Unchanged GFR
• D. Decreased GFR

Answer: (D)

As people age, the kidneys undergo changes such as loss of functioning nephrons and reduced renal blood flow, which together lower the filtration capacity. This leads to a gradual decline in the glomerular filtration rate, so describing the GFR as decreased best fits the typical aging pattern. A normal or unchanged GFR would not reflect this age-related decline, and an increased GFR is not expected with aging. In practice, recognizing a lower GFR in older adults helps explain why drug clearance can be reduced and why careful dosing and monitoring of fluids and electrolytes are important; clinicians often use estimated GFR to gauge kidney function while considering age-related changes.