Successful results of pamidronate treatment in children with osteogenesis imperfecta with emphasis on the interpretation of bone mineral density for local standards.
OBJECTIVE
To assess the long-term effect of pamidronate therapy on bone mineral metabolism and bone mineral density (BMD) in children with osteogenesis imperfecta (OI) and to evaluate BMD results with respect to national standards.


METHODS
Pamidronate was administered intravenously on 3 consecutive days every 3 to 4 months at a dose of 1 mg/kg/d in 35 patients. Infusion cycles ranged from 4 to 17. Serum calcium, phosphorus, bone turnover markers, L1-L4 areal BMD (aBMD), and fracture rate were evaluated. Areal BMD Z scores were compared with national sex-specific reference data and volumetric BMD Z scores.


RESULTS
In all children, linear growth continued along the same percentile during treatment. All parameters of bone turnover showed a decrease. L1 to L4 aBMD and Z score increased markedly, and fracture rate decreased in all patients during therapy. The mean annual percent gain in aBMD was highest in the first year and slowed down in subsequent years. Mean L1 to L4 aBMD Z scores according to Turkish reference data were higher than that of manufacturer values (P = 0.004). Correction of L1 to L4 vertebrae for bone size yielded to a decrease in osteoporosis in OI patients (41.5% vs 22.3%).


CONCLUSIONS
Bone mineral density increased and fracture rate decreased in children and infants with OI during pamidronate treatment. Prevalence of osteoporosis decreased after correction for national standard and volumetric BMD. Use of an appropriate reference database and method of data analysis are very important for correct evaluation of osteoporosis.
Pediatric Endocrinology Unit, Department of Pediatrics, Faculty of Medicine, Istanbul University, Istanbul, Turkey. sukranpoyrazoglu@yahoo.com
Sukran
S
Poyrazoglu
Hulya
H
Gunoz
Feyza
F
Darendeliler
Firdevs
F
Bas
Filiz
F
Tutunculer
Sema Kabatas
SK
Eryilmaz
Ruveyde
R
Bundak
Nurcin
N
Saka
D000293:Adolescent; D000893:Anti-Inflammatory Agents; D015519:Bone Density / Q000187:drug effects*; D050071:Bone Density Conservation Agents / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D004164:Diphosphonates / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007275:Injections, Intravenous; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D008297:Male; D010013:Osteogenesis Imperfecta / Q000000981:diagnostic imaging / Q000188:drug therapy*; D000077268:Pamidronate; D011859:Radiography; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
D000893:Anti-Inflammatory Agents; D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D000077268:Pamidronate