Idiopathic juvenile osteoporosis (IJO) is a rare form of bone demineralization that occurs during childhood. The mechanism of bone loss is unclear. Some bone hystomorphometric studies have found osteoblast failure and decreased bone formation in the affected patients whereas others have reported increased bone resorption. To elucidate this issue, we studied osteoblast function in six patients with IJO (five males, one female; aged 2.3-14.6 years) and five healthy sex- and age-matched subjects (four males, one female; aged 2.0-15.1 years) measuring serum values of osteocalcin under basal condition and during an osteoblast stimulation test performed by oral 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] administration (1.8-mu-g/1.73 m2 /daily). After a baseline day (day 0), all the subjects (patients and controls) received 1,25(OH)2D3 in four divided doses for 6 days (days 1-6). Fasting blood samples were obtained every morning (0800 h) for the determination of serum osteocalcin. Baseline osteocalcin levels were not significantly different between IJO and controls (13.58 +/- 6.05 ng/ml versus 16.04 +/- 5.09 ng/ml, respectively) even if two patients had low osteocalcin values. During 1,25(OH)2D3 administration, serum osteocalcin values significantly increased (P < 0.001) from baseline in both children with IJO and controls, reaching peak values not significantly different in the two groups. Our results do not support the hypothesis that defective osteoblast function is the primary factor of bone demineralization in IJO.

Idiopathic juvenile osteoporosis - evidence of normal osteoblast function by 1,25-dihydroxyvitamin-d3 stimulation test

SAGGESE, GIUSEPPE
1992

Abstract

Idiopathic juvenile osteoporosis (IJO) is a rare form of bone demineralization that occurs during childhood. The mechanism of bone loss is unclear. Some bone hystomorphometric studies have found osteoblast failure and decreased bone formation in the affected patients whereas others have reported increased bone resorption. To elucidate this issue, we studied osteoblast function in six patients with IJO (five males, one female; aged 2.3-14.6 years) and five healthy sex- and age-matched subjects (four males, one female; aged 2.0-15.1 years) measuring serum values of osteocalcin under basal condition and during an osteoblast stimulation test performed by oral 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] administration (1.8-mu-g/1.73 m2 /daily). After a baseline day (day 0), all the subjects (patients and controls) received 1,25(OH)2D3 in four divided doses for 6 days (days 1-6). Fasting blood samples were obtained every morning (0800 h) for the determination of serum osteocalcin. Baseline osteocalcin levels were not significantly different between IJO and controls (13.58 +/- 6.05 ng/ml versus 16.04 +/- 5.09 ng/ml, respectively) even if two patients had low osteocalcin values. During 1,25(OH)2D3 administration, serum osteocalcin values significantly increased (P < 0.001) from baseline in both children with IJO and controls, reaching peak values not significantly different in the two groups. Our results do not support the hypothesis that defective osteoblast function is the primary factor of bone demineralization in IJO.
Bertelloni, S; Baroncelli, Gi; Dinero, G; Saggese, Giuseppe
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11568/18374
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? 12
social impact