Evaluation of Body Composition in Paediatric Osteogenesis Imperfecta.

Osteogenesis Imperfecta (OI) is a skeletal disorder characterised by a predisposition to recurrent fractures and bone deformities. Clinically OI is defined by features such as short stature, however, less is known regarding body composition. Assess body composition, both lean mass and fat mass, in a paediatric OI population. Children with OI attending the Bone service at the Royal Hospital for Children Glasgow were included; who had a dual-energy x-ray absorptiometry (DXA) scan performed 2015-2018. Height and body-mass-index (BMI) were converted to standard-deviation scores (SDS) using UK population references. DXA-derived lean mass and fat mass were used to generate lean-mass-index (LMI) and fat-mass-index (FMI) by dividing the covariates by height squared. LMI and FMI were converted to age-and-gender-adjusted SDS using DXA data from 198 local healthy children. Thirty-eight children (20 males) with median age 11.95 (range: 4.8, 18.3) years were included. Median height SDS was -1.08 (-3.64, 1.62) and was significantly lower than the healthy population (p<0.0001). Median BMI SDS was -0.10 (-2.31, 2.95), and not significantly different from the healthy population (p = 0.53). Median LMI SDS was -2.52 (-6.94, 0.77), and significantly lower than healthy controls (p<0.0001); 61% (23/38) had an SDS below -2.0. Median FMI SDS was 0.69 (-0.45, 2.72), significantly higher than healthy controls (p < 0.0001). BMI SDS cut-offs of -0.15 and 1.33, from ROC analysis, identified children with LMI SDS <-2, with a positive predictive value of 95% and a negative predictive value of 70%; and FMI SDS >2 with a positive predictive value of 44% and a negative predictive value of 100%. A contemporary population of children with ranging severities of OI present with significant reduction in height and lean mass, and relatively high fat mass. Standard BMI SDS cut-offs for identifying children with malnutrition and obesity have poor prognostic validity in OI.

A survey of the feasibility of developing osteoporosis clinical trials in Duchenne muscular dystrophy: Survey of the opinion of young people with Duchenne muscular dystrophy, families and clinicians.

BACKGROUND/AIMS: Given the extent of osteoporosis in people with Duchenne muscular dystrophy treated with glucocorticoids and the limited evidence of bone-protective therapies, clinical trials are needed. We conducted surveys to obtain the opinion of young people with Duchenne muscular dystrophy, parents/guardians and neuromuscular clinicians on the feasibility of osteoporosis clinical trials in this population. METHODS: Online surveys were sent to three groups: (a) people with a confirmed diagnosis of Duchenne muscular dystrophy (≥14 years), (b) parents and guardians and (c) neuromuscular clinicians in the UK NorthStar Clinical Network. Surveys (a) and (b) were distributed via the UK Duchenne muscular dystrophy Registry. RESULTS: Survey respondents included 52 people with Duchenne muscular dystrophy with a median age of 17 years (range: 14, 40) and 183 parents/guardians. Fourteen out of 23 (61%) NorthStar centres responded. Of the 52 people with Duchenne muscular dystrophy, 13 (25%) were very concerned about their bone health and 21 (40%) were slightly concerned. Of the 183 parents/guardians, 75 (41%) were very concerned about their son's bone health and 90 (49%) were slightly concerned. Fractures and quality of life were the top two main outcome measures identified by people with Duchenne muscular dystrophy. Fractures and bone density were the top two main outcome measures identified by parents/guardians and neuromuscular clinicians. Thirty percent of people with Duchenne muscular dystrophy and 40% of parents/guardians would not take part if an osteoporosis trial involved a placebo that was administered parenterally. Only 2 of the 14 NorthStar centres (14%) would enrol people with Duchenne muscular dystrophy if a parenteral placebo was used in an osteoporosis trial in Duchenne muscular dystrophy. CONCLUSION: There is great awareness of bone health and the need for bone-protective trials among people with Duchenne muscular dystrophy and their carers. However, a proportion of people with Duchenne muscular dystrophy and parents are reluctant to participate in a placebo-controlled osteoporosis trial that included a parenteral therapy. A larger proportion of health care experts are unwilling to enrol their patients in such a trial. Our finding is relevant for the design of bone-protective studies in Duchenne muscular dystrophy.

Assessing Osteoporosis in the Young Adult.

Osteoporosis in the young adult is a relatively rare phenomenon, and its diagnosis needs careful assessment of the affected person. The emphasis in the assessment of bone health is gradually shifting from a simple quantitative assessment of bone mineral density to one that includes bone quality. This may be particularly important in the young adult, where the aetiological cause of osteoporosis may be a primary genetic condition or secondary to another chronic condition.