G.P.172: Renal function in children and adolescents with Duchenne muscular dystrophy: a prospective study

Abstract

Objectives: Improved life expectancy and the need for robust tools to monitor renal safety of emerging new therapies have fueled the interest in renal function in patients with Duchenne muscular dystrophy (DMD). We aimed to establish methodology for studying renal function in patients with DMD and using this methodology, to describe their renal function in detail. Methods: Twenty participants (5–22years old) were selected for a prospective cross-sectional study. Medical history was obtained and all patients underwent a physical examination, 24-h ambulatory blood pressure monitoring, ultrasound of the kidneys, 51 Cr-EDTA for GFR measurement (mGFR), blood and urine analysis. Results: Between February 2013 and July 2013, twenty patients were included. The median age was 15.5years. Twelve patients were treated with corticosteroids. Total protein/creatinine was increased in 17/18 patients, whereas 24-h urine protein was normal in 18/18 subjects. We detected nine patients with 51 Cr-EDTA GFR >P90 (135ml/min/m 2 ) and one patient with 51 Cr-EDTA GFR 2 . Median mGFR was 128ml/min/1.73m 2 . Nephromegaly (1 or 2 kidneys with a length >2SD) was found in 6/20 subjects. Hypertension (systolic and/or diastolic blood pressure >P95) was found in 9/20 subjects and a non-dipping profile was found in 13/20 subjects. Conclusions: This small prospective study demonstrates that urinary protein excretion expressed in mg creatinine is not reliable in DMD patients because of low urinary creatinine. We report a high prevalence of hyperfiltration, nephromegaly and hypertension corrected for body size. Our current findings on renal function and outcome in DMD patients require further studies to investigate the pathogenesis, the confounding issue of chronic steroid treatment and long-term prognosis.