GFR for stage 1 kidney damage with normal or high GFR?

• A. > 90 mL/min/1.73 M2
• B. 60-80 mL/min/1.73 M2
• C. 30-59 mL/min/1.73 M2
• D. 15-20 mL/min/1.73 M2

Answer: (A)

Stage 1 CKD is defined by kidney damage with a normal or high GFR. Normal/high GFR is 90 mL/min/1.73 m^2 or greater, so the GFR threshold for stage 1 is at least 90, as long as there is evidence of kidney damage such as albuminuria or imaging/biopsy findings. Values below that fall into later stages (stage 2: 60–89 with damage; stage 3: 30–59; stage 4: 15–29; stage 5: <15). The important point is that stage 1 requires both kidney damage and a GFR in the normal/high range.