title: Low bone mineral density and fractures are highly prevalent in pediatric patients with spinal muscular atrophy regardless of disease severity.
abstract: Patients with Spinal Muscular Atrophy (SMA) are at risk for poor bone health. The prevalence of fractures, low areal bone mineral density (aBMD; Z-score ≤-2.0) of the lateral distal femur and of osteoporosis by SMA subtype is not known. We aimed to describe the natural history of bone health in patients with SMA prior to bisphosphonate treatment. We reviewed data from 85 eligible patients with SMA ages 12 months to 18 years, seen at a single institution between January 2005 and July 2016. Fracture history was reported at annual clinic visits. aBMD was obtained from dual energy x-ray absorptiometry scans of the lumbar spine, total body, and lateral distal femur. 85% of patients had aBMD Z-scores ≤-2.0 SD and were progressively lower with worsening SMA severity. Longitudinal aBMD Z-scores of the lateral distal femur decreased with age. Fractures occurred in 38% (32/85) of patients with the femur being the most common location (25 of 57 fractures). Thirteen percent of patients fulfilled criteria for osteoporosis. Low aBMD and femur fractures are highly prevalent in all SMA subtypes from a young age; however, few patients met the criteria for osteoporosis. Poor bone health may be an under-recognized comorbidity of SMA.
authors.affiliation: Cincinnati Children's Hospital Medical Center, Division of Endocrinology, 3333 Burnet Ave, MLC 7012, Cincinnati, OH 45229, USA. Electronic address: halley.wasserman@cchmc.org.
authors.forename: Halley M
authors.initials: HM
authors.lastname: Wasserman
authors.affiliation: Cincinnati Children's Hospital Medical Center, Division of Biostatistics and Epidemiology, 3333 Burnet Ave, MLC 5041, Cincinnati, OH 45229, USA.
authors.forename: Lindsey N
authors.initials: LN
authors.lastname: Hornung
authors.affiliation: Cincinnati Children's Hospital Medical Center, Division of Endocrinology, 3333 Burnet Ave, MLC 7012, Cincinnati, OH 45229, USA.
authors.forename: Peggy J
authors.initials: PJ
authors.lastname: Stenger
authors.affiliation: Cincinnati Children's Hospital Medical Center, Division of Endocrinology, 3333 Burnet Ave, MLC 7012, Cincinnati, OH 45229, USA.
authors.forename: Meilan M
authors.initials: MM
authors.lastname: Rutter
authors.affiliation: Cincinnati Children's Hospital Medical Center, Division of Child Neurology, 3333 Burnet Ave, MLC 2015, Cincinnati, OH 45229, USA.
authors.forename: Brenda L
authors.initials: BL
authors.lastname: Wong
authors.affiliation: Cincinnati Children's Hospital Medical Center, Division of Child Neurology, 3333 Burnet Ave, MLC 2015, Cincinnati, OH 45229, USA.
authors.forename: Irina
authors.initials: I
authors.lastname: Rybalsky
authors.affiliation: Cincinnati Children's Hospital Medical Center, Division of Endocrinology, 3333 Burnet Ave, MLC 7012, Cincinnati, OH 45229, USA; Cincinnati Children's Hospital Medical Center, Division of Biostatistics and Epidemiology, 3333 Burnet Ave, MLC 5041, Cincinnati, OH 45229, USA.
authors.forename: Jane C
authors.initials: JC
authors.lastname: Khoury
authors.affiliation: Cincinnati Children's Hospital Medical Center, Division of Gastroenterology, Hepatology and Nutrition, 3333 Burnet Ave, MLC 2010, Cincinnati, OH 45229, USA.
authors.forename: Heidi J
authors.initials: HJ
authors.lastname: Kalkwarf
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D015519:Bone Density / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D007223:Infant; D008297:Male; D009134:Muscular Atrophy, Spinal / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology*; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D015995:Prevalence; D012720:Severity of Illness Index
keywords: Children; Dual energy x-ray absorptiometry; Osteoporosis