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Resume Propos Le but de cette etude etait de determiner les facteurs associes a la valeur de la densite minerale osseuse (DMO) mesuree au niveau du col du femur dans un groupe de femmes d'âge moyen considerees a risque d'osteoporose (statut precaire en vitamine D [25(OH)D3 36 pg/mL]). Methodes Cette etude a ete conduite en deux temps chez 122 femmes de la cohorte SUVIMAX (supplementation en vitamines et mineraux antioxydants). L'impact de differentes variables, dont l'âge, l'indice de masse corporelle (IMC), le statut en vitamine D, la consommation d'alcool, l'intensite d'exposition au soleil et le phototype sur la DMO a ete teste a l'aide de modeles de regression. Resultats Aucun lien significatif n'a ete retrouve entre la DMO et les variables documentant le statut en vitamine D et le taux de parathormone, ni le phototype. Cependant, les phototypes les plus clairs ont tendance a etre associes avec les valeurs les plus basses de DMO. En revanche, la valeur moyenne de la DMO diminue significativement avec l'âge et augmente avec l'indice de masse corporelle et le niveau d'activite physique. Conclusion Quel que soit leur phototype, les femmes a statut precaire en vitamine D devraient adopter une supplementation en vitamine D associee a un apport adapte en calcium tout au long de l'annee, sans negliger l'adoption de mesures de protection solaire et le maintien d'un niveau satisfaisant d'activite physique, pour ameliorer leur densite osseuse et prevenir le risque fracturaire.

Objective: To assess the cost implications for a preventive treatment strategy for institutionalised elderly women with a combined 1200 mg/day calcium and 800 IU/day vitamin D3 supplementation in seven European countries. Design: Retrospective cost effectiveness analysis based on a prospective placebo-controlled randomised clinical trial. Data sources: Recently published cost studies in seven European countries. Clinical results from Decalyos, a 3-year placebo-controlled study in elderly institutionalised women. Trials: Decalyos study, with 36 months follow-up of 3270 mobile elderly women living in 180 nursing homes, allocated to two groups. One group received 1200 mg/day elemental calcium in the form of tricalcium phosphate together with 800 IU/day (20 μg) of cholecalciferol (vitamin D3), the other placebo. Results: In the 36 months analysis of the Decalyos study, 138 hip fractures occurred in the group of 1176 women, receiving supplementation and 184 hip fractures in the placebo group of 1127 women. The mean duration of treatment was 625.4 days. Adjusted to 1000 women, 46 hip fractures were avoided by the calcium and vitamin D3 supplementation. For all countries, the total costs in the placebo group were higher than in the group receiving supplementation, resulting in a net benefit of €79 000–711 000 per 1000 women. Conclusion: This analysis suggests that the supplementation strategy is cost saving. The results may underestimate the net benefits, as this treatment has also shown to be effective in decreasing the incidence of other non-vertebral fractures in elderly institutionalised women.

The early effects of two doses of sodium fluoride (NaF) on bone remodeling was studied in 14 ewes divided into two groups. Group I received orally 1 mg NaF/kg/day and group II received a five-fold greater dose. No calcium supplement was given. Transiliac bone biopsies and blood samples were taken before treatment (T0) and after 45 (T45) days of treatment. Bone fluoride content significantly increased in group II. In both groups, a significant decrease of serum calcium and phosphorus, and a slight but nonsignificant augmentation in serum parathyroid hormone were noted. Osteoid perimeter and area were significantly increased. The osteoid width significantly increased in both groups, but was twice higher in group II than I. At T45, the osteoblast perimeter increased in both groups. Osteoid perimeter was significantly correlated with serum osteocalcin values (r = 0.74; p less than 0.001) and bone fluoride content (r = 0.64; p less than 0.01). The bone formation rate at tissue level tended to increase in both groups. Concerning the apposition rate, a decrease was noted which was 1.5-fold higher in group II than in I. The increased formation period resulted from a prolonged inactive period in group II. These results point out a stimulatory effect of fluoride on the birth rate of osteoblasts. However, fluoride prolonged the lifespan of osteoblasts that had reduced activity.

We have previously shown that elderly women with an increased serum undercarboxylated osteocalcin (ucOC) level have an increased risk of sustaining a hip fracture as compared to those with normal serum ucOC. We reassessed our findings on a larger number of hip fractures that occurred over 3 years in 183 institutionalized women (aged 70-97 years) belonging to a large prospective clinical trial. Total OC, carboxylated OC, ucOC, and alkaline phosphatase were significantly higher at baseline in those who sustained a hip fracture during the follow-up. The age-adjusted odds ratio for hip fracture was three times higher in women with increased ucOC at baseline (odds ratio = 3.1, 99.9% C.I. = 1.7-6.0, p < 0.001). In the logistic regression, ucOC was still predictive of the hip fracture when age and parathyroid hormone concentration were included into the model (odds ratio = 2.6, 95% C.I. = 1.05-6.4). These data confirm that ucOC is a marker of the increased risk of hip fracture in elderly institutionalized women. Serum ucOC may reflect some nutritional deficiency associated with increased bone fragility.

A hemodialyzed patient showing x-ray and biochemical evidence of apparently pure severe hyperparathyroidism underwent a tetracycline-labeled transiliac bone biopsy. The bone biopsy not only confirmed the hyperparathyroid bone lesions but also revealed an impairment of bone mineralization induced by aluminum. This was demonstrated by a reduction of double-labeled osteoid surfaces, a significant increase in the osteoid seam thickness, and the presence of extensive aluminum deposits in bone. The planned parathyroidectomy was postponed, and deferoxamine (DFO) therapy, 2 g once a week, was initiated. A second bone biopsy, taken 6 months later, showed recovery of normal bone mineralization but the persistence of hyperparathyroid bone lesions. This was associated with a considerable reduction in the extent of aluminum deposits on trabecular bone surfaces. This observation shows that severe and apparently pure hyperparathyroidism can be associated with an impairment of bone mineralization induced by aluminum. This suggests that bone mineralization and aluminum overload should be evaluated in dialyzed patients who are being considered for parathyroidectomy.

Calcium and vitamin D status were studied in 193 healthy elderly French people. Calcium intake was less than 500 mg/d in 62% of the patients and the vitamin D intake was less than 5 micrograms/d in all patients. They also exhibited reduced levels of serum calcium (SCa) and 25-hydroxyvitamin D (25-OHD) and high levels of parathyroid hormone (PTH) and alkaline phosphatase (SAP). The response to calcium (1000 mg/d) and ergocalciferol (20 micrograms/d) supplementation given for 6 mo was evaluated in 65 patients with 69 subjects taken as controls. The treatment induced a significant increase in SCa and in 25-OHD levels, and a subsequent decrease in PTH levels without modification of the mean calcitriol levels. The biochemical changes were more marked in long-stay hospital patients than in outpatients. All these changes were significantly different from those observed in the control group. Increasing the calcium and vitamin D intake reduces the biochemical signs of secondary hyperparathyroidism in elderly people.

Clinical and biochemical resistance to sodium etidronate therapy is not rare in patients with severe Paget's disease of bone, especially after several courses of treatment. Sixteen patients with Paget's disease of bone and well-documented resistance to sodium etidronate were treated with a new diphosphonate, aminohexane diphosphonate, given orally for three months at a daily dose of 400 mg. These patients comprised a selected population of patients with very active disease, as shown by a mean 20-fold increase of serum alkaline phosphatase levels before aminohexane diphosphonate therapy. Aminohexane diphosphonate induced a striking reduction of serum alkaline phosphatase and urinary hydroxyproline levels sustained for up to 18 months after withdrawal of treatment. Two patients had a relapse 14 to 16 months after treatment, and received a second course of aminohexane diphosphonate with the same efficacy. This was accompanied by marked clinical improvement, a reduction of the radioisotope uptake by pagetic bones, and radiologic healing of osteolytic lesions in some cases. Iliac crest biopsy specimens taken after tetracycline double-labeling showed no impairment of bone mineralization. No clinical or biochemical adverse effects have been observed.