Low bone mass in patients with motor disability: prevalence and risk factors in 59 Finnish children.
OBJECTIVE
Children with motor disabilities are at increased risk of compromised bone health. This study evaluated prevalence and risk factors of low bone mass and fractures in these children.


METHODS
This cross-sectional cohort study evaluated bone health in 59 children (38 males, 21 females; median age 10 y 11 mo) with motor disability (Gross Motor Function Classification System levels II-V). Bone mineral density (BMD) in the lumbar spine was measured with dual-energy X-ray absorptiometry; BMD values were corrected for bone size (bone mineral apparent density [BMAD]) and skeletal maturity, and compared with normative data. Spinal radiographs were obtained to assess vertebral morphology. Blood biochemistry included vitamin D concentration and other parameters of calcium homeostasis.


RESULTS
Ten children (17%) had sustained in total 14 peripheral fractures; lower-limb fractures predominated. Compression fractures were present in 25%. The median spinal BMAD z-score was -1.0 (range -5.0 to 2.0); it was -0.6 in those without fractures and -1.7 in those with fractures (p=0.004). Vitamin D insufficiency was present in 59% of participants (serum 25-hydroxyvitamin D <50 nmol/l) and hypercalciuria in 27%. Low BMAD z-score and hypercalciuria were independent predictors for fractures.


CONCLUSIONS
Children with motor disability are at high risk of peripheral and vertebral fractures and low BMD. Evaluation of bone health and prevention of osteoporosis should be included in the follow-up.
Kilpinen-Loisa
Päivi
P
Department of Paediatric Neurology, Päijät-Häme Central Hospital, Lahti, Finland. paivi.kilpinen-loisa@phsotey.fi
Paasio
Taava
T
Soiva
Martti
M
Ritanen
Ulla Maija
UM
Lautala
Pentti
P
Palmu
Petri
P
Pihko
Helena
H
Mäkitie
Outi
O
D015502:Absorptiometry, Photon / Q000295:instrumentation; D015519:Bone Density / Q000502:physiology*; D001847:Bone Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology*; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005260:Female; D005387:Finland / Q000453:epidemiology; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000453:epidemiology; D006801:Humans; D053565:Hypercalciuria / Q000453:epidemiology; D008297:Male; D009069:Movement Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D010024:Osteoporosis / Q000175:diagnosis; D011237:Predictive Value of Tests; D015995:Prevalence; D012307:Risk Factors; D014808:Vitamin D Deficiency / Q000453:epidemiology