J. Bange

Bone health measures in glucocorticoid-treated ambulatory boys with Duchenne muscular dystrophy

Osteoporosis is a major problem in boys with Duchenne Muscular Dystrophy (DMD), attributable to muscle weakness and glucocorticoid therapy. Consensus regarding bone health assessment and management is lacking. Lumbar spine areal bone mineral density (defined as bone mass per area of bone) by dual-energy X-ray absorptiometry (DXA) is frequently the primary measure used, but has limitations for boys with DMD. We retrospectively studied 292 ambulant glucocorticoid-treated boys with DMD categorized by functional mobility score, FMS 1, 2 or 3. We assessed DXA whole body and lumbar spine areal bone mineral density and content Z-scores adjusted for age and height, lateral distal femur areal bone mineral density Z-scores, frequency of fractures, and osteoporosis by International Society for Clinical Densitometry 2013 criteria. Whole body and femoral DXA indices decreased, while spine fractures increased, with declining motor function. Lumbar spine areal bone mineral density Z-scores appeared to improve with declining motor function. Bone mineral content Z-scores were consistently lower than corresponding bone mineral density Z-scores. Our findings highlight the complexity of assessing bone health in boys with DMD. Bone health indices worsened with declining motor function in ambulant boys, but interpretation was affected by measure and skeletal site examined. Whole body bone mineral content may be a valuable measure in boys with DMD. Lumbar spine areal bone mineral density Z-score as an isolated measure could be misleading. Comprehensive management of osteoporosis in boys with DMD should include vertebral fracture assessment.

G.P.171

Osteoporosis is a major problem in Duchenne Muscular Dystrophy (DMD) patients due to long term glucocorticoid (GC) therapy and immobility. There is neither age-specific prevalence data nor consensus on management of osteoporosis in DMD. To determine age-specific prevalence of osteoporosis and frequency of poor bone health indices in pediatric DMD patients. Methods: We retrospectively examined age-specific prevalence of osteoporosis and poor bone health indices in GC-treated DMD patients seen between January 2005 and July 2012 at Cincinnati Children’s Hospital. Outcomes of interest were fractures (total, vertebral, long bone), and low age- and height-adjusted z -scores ( z -scores also increased with age, and varied with site of measurement. Osteoporosis is frequent in DMD patients from a young age. Our study is the first to examine age-specific prevalence of osteoporosis and frequency of poor bone health indices throughout the pediatric age span in a large DMD cohort. These data also highlight the complexity of bone health measures, and the urgent need to improve detection, prevention and treatment of osteoporosis in DMD.

MYOCARDIAL SCAR BURDEN INCREASES WITH AGE AND IS ASSOCIATED WITH DECLINE IN LEFT VENTRICULAR SYSTOLIC FUNCTION IN YOUNG PATIENTS WITH BECKER MUSCULAR DYSTROPHY

Duchenne Muscular Dystrophy (DMD) patients develop myocardial fibrosis with associated systolic dysfunction. Despite milder skeletal myopathy, cardiomyopathy onset is thought to occur earlier in Becker Muscular Dystrophy (BMD) than DMD. 1) BMD patients show age-related late gadolinium enhancement (

G.P.178

DMD patients on long term daily glucocorticoid (GC) therapy are at risk for excessive weight gain and linear growth failure. The impact of excessive weight gain and short stature on motor function is unclear. Objective : To evaluate height, weight and BMI of DMD patients on long term glucocorticoid therapy; and to study the correlation of height, weight and BMI with timed motor function. Cross-sectional retrospective case series review of GC treated DMD patients Results : 110 males aged 7 to ⩽13years were treated with daily GC for 4.8±1.5years and followed at our clinic for 4.8±1.6years. 7.3% were on metformin for insulin resistance and 17.3% were on growth hormone for growth failure. There was no excessive weight growth in 62% of patient; observed weight %tiles vs normal weight %tiles had a correlation coefficient, r >0.99. 61% of patients had heights rd %tile (53% of 7– 10years old). 26% of patients were overweight (BMI 85th −95th %tile) and 34% were obese (BMI>95th %tile). Height %tiles were not correlated with timed 30 foot run (run), Gower (G) and North Star Ambulatory Assessment (NSAA) Scores. Weight %tiles correlated positively with times for G ( p 0.027) and negatively with NSAA ( p 0.004). BMI %tiles correlated positively with times for run ( p 0.011) and G ( p 0.005); and negatively with NSAA ( p 0.0009). The weight and BMI correlations were stronger for patients older than 10years of age. The mean NSAA score and times for run and Gower for the overweight and obese patients (BMI>85th %tile) reflected worse motor function than patients with normal BMI p 0.011; G p 0.013; NSAA p 0.004). For daily GC treated DMD patients, excessive weight gain is not a complication in 62%; short stature