Duchenne Muscular Dystrophy with Extreme Emaciation and a Discrepancy between Cystatin C-based eGFR and Inulin Clearance.

We describe the case of a 25-year-old male with Duchenne muscular dystrophy and acute kidney injury who was receiving mechanical ventilation. The patient's estimated glomerular filtration rate (eGFR) was assessed using formulas based on creatinine, cystatin C, and inulin levels over time during the recovery of his renal function. The creatinine-based eGFR was extremely high throughout the study period. The cystatin C-based eGFR was also higher than the inulin clearance. These findings suggest that cystatin C-based eGFR may also exceed inulin clearance in patients with an extremely reduced fat mass, in addition to a reduced muscle mass.