eGFR 60 to 89 mL/min/1.73m²

KDIGO labels 60 to 89 "Mildly decreased" and adds, in the same table footnote, "Relative to the young adult level. In the absence of evidence of kidney damage, neither G1 nor G2 fulfills the criteria for CKD." That footnote is the whole rule for this band. A 72 with a normal urine albumin-to-creatinine ratio is a common finding in a healthy adult, especially past midlife; a 72 with an ACR of 30 mg/g or higher, persisting 3 months, is chronic kidney disease.

Age, in KDIGO's own words. The guideline recognizes "an average age-associated GFR decline observed in longitudinal and cross-sectional studies, but with substantial variation among individuals within the population, such that not all individuals will have a significant GFR decline with age." It considered proposals to raise the CKD threshold to 75 for younger adults and lower it to 45 for older adults, and declined both: "the existing CKD staging is appropriate among both younger and older adults." Its advice for a younger adult in this band is prevention rather than a label: "Efforts should be directed at people with higher risk with GFR levels >60 ml/min per 1.73 m2 to prevent the incidence of CKD or further reductions in GFR." For older adults it warns the other way, that creatinine-based eGFR "will overestimate GFR in the elderly (and others) with sarcopenia leading to drug overdosing."

What to do. Check the urine ACR; KDIGO confirms an incidental result on a first-morning sample and does not diagnose chronicity from a single value. With a normal ACR the monitoring figure says screen once a year. With albuminuria the G2 row matches G1: treat, with measurement once a year at A2 and three times a year at A3. KDIGO's laboratory standard flags an eGFR only when it is under 60, so a report will not flag this band; the reason to look at the ACR is exactly that.

Treatment that switches on with albuminuria. The ACE inhibitor or ARB recommendations (3.6.1 to 3.6.3) cover G1 through G4 by albuminuria category, with or without high blood pressure. SGLT2 inhibitors are recommended for type 2 diabetes with CKD, or for an ACR of 200 mg/g or higher, or heart failure (3.7.1 and 3.7.2, both 1A). A statin is recommended for adults 50 and older with CKD at G1 or G2 (3.15.1.2, 1B); for adults 18 to 49, KDIGO suggests one with coronary disease, diabetes, prior ischemic stroke or a 10-year coronary risk over 10 percent (3.15.1.3, 2A). Before any of that, KDIGO's practice point on creatinine applies to everyone: a cooked meat or fish meal can raise serum creatinine enough to move eGFR by about 20 points for a few hours, and waiting at least 12 hours after one "best avoids this effect."