A 71-year-old woman presents with fatigue. Laboratory studie…

A 71-yeаr-оld wоmаn presents with fаtigue. Labоratory studies reveal: Laboratory Result Normal Creatinine 2.0 mg/dL 0.6–1.3 eGFR 32 mL/min/1.73m² ≥90 Review of previous records shows similar values for the past two years for both creatinine and eGFR.  Which diagnosis is most likely?