Serum creatinine level: a supplemental index to distinguish Duchenne muscular dystrophy from Becker muscular dystrophy.

BACKGROUND: To improve assessment of dystrophinopathy, the aim of this study was to identify whether serum creatinine (Crn) level reflects disease severity.

METHODS: Biochemical, Vignos score, and genetic data were collected on 212 boys with dystrophinopathy.

RESULTS: Serum Crn level had a strong inverse correlation with Vignos score by simple correlation (r = -0.793) and partial correlation analysis after adjustment for age, height, and weight (r = -0.791; both P < 0.01). Serum Crn level was significantly higher in patients with in-frame than out-of-frame mutations (Z = -4.716,  P < 0.01) and in Becker muscular dystrophy (BMD) patients than Duchenne muscular dystrophy (DMD) patients at ages 4, 5, 7, and 9 yr (all P < 0.0125). After adjusting for age, height, and weight, BMD patients still had a significantly higher serum Crn level than DMD patients (β = 7.140,  t = 6.277,  P < 0.01).

CONCLUSIONS: Serum Crn level reflected disease severity and may serve as a supplemental index to distinguish DMD from BMD in clinical practice.