title: Impaired bone health and asymptomatic vertebral compressions in fracture-prone children: a case-control study.
abstract: Frequent fractures in children may be a sign of impaired bone health, but it remains unestablished when and how fracture-prone children should be assessed. This prospective study elucidated skeletal characteristics and predisposing factors in children with recurrent fractures. Findings were used to establish guidelines for screening. During a 12-month period we recorded fracture history for all children (n = 1412) treated for an acute fracture at a large university hospital. All apparently healthy children over 4 years of age, who had sustained: (1) at least one vertebral fracture; (2) two long-bone fractures before age 10 years; or (3) three long-bone fractures before age 16 years, were recruited. They underwent dual-energy X-ray absorptiometry (DXA), laboratory tests, and spinal radiography. Information regarding family history and lifestyle factors were collected. Findings were compared with healthy controls. Sixty-six fracture-prone children (44 males, mean age 10.7 years; 5% of all children with fractures) were identified. Altogether, they had sustained 183 long-bone fractures (median 3, range 0–7); 11 children had sustained vertebral fracture(s). Patients had significantly lower bone mineral density (BMD) at lumbar spine (p < 0.001), hip (p = 0.007), and whole body (p < 0.001) than the controls; only 5 children (8%) had a BMD Z-score < −2.0. Asymptomatic vertebral compressions were prevalent, especially in those under 10 years of age. Hypercalciuria (11%) and hyperphosphaturia (22%) were significantly more prevalent than in controls. Serum concentration of 25-hydroxyvitamin D (S-25OHD) was below 50 nmol/L in 55%; low levels were associated with low BMD and vertebral compressions. The fracture-prone children had lower calcium intake, less physical activity, and more often had siblings with fractures than the controls. The findings suggest that a thorough pediatric evaluation, including DXA and spinal radiography, is often indicated already after a second significant low-energy fracture in children, in order to detect potentially preventable adverse lifestyle factors and nutritional deficits and to identify those with compromised overall bone health.
authors.affiliation: Children's Hospital, Helsinki University Central Hospital and University of Helsinki, Stenbäckinkatu 11, HUS, Helsinki, Finland. mervi.mayranpaa@helsinki.fi
authors.forename: Mervi K
authors.initials: MK
authors.lastname: Mäyränpää
authors.forename: Heli T
authors.initials: HT
authors.lastname: Viljakainen
authors.forename: Sanna
authors.initials: S
authors.lastname: Toiviainen-Salo
authors.forename: Pentti E
authors.initials: PE
authors.lastname: Kallio
authors.forename: Outi
authors.initials: O
authors.lastname: Mäkitie
mesh_terms: D015519:Bone Density; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D002118:Calcium / Q000652:urine; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003710:Demography; D005260:Female; D005387:Finland / Q000453:epidemiology; D050815:Fractures, Compression / Q000097:blood / Q000150:complications / Q000453:epidemiology* / Q000652:urine; D006262:Health; D006801:Humans; D008297:Male; D010024:Osteoporosis / Q000097:blood / Q000150:complications / Q000453:epidemiology / Q000652:urine; D010710:Phosphates / Q000652:urine; D015995:Prevalence; D011859:Radiography; D012307:Risk Factors; D016103:Spinal Fractures / Q000097:blood / Q000150:complications / Q000453:epidemiology* / Q000652:urine; D014807:Vitamin D / Q000097:blood
chemical_list: D010710:Phosphates; D014807:Vitamin D; D002118:Calcium