Raloxifene plus ossein-hydroxyapatite compound versus raloxifene plus calcium carbonate to control bone loss in postmenopausal women: a randomized trial

Efficacy and safety of ossein-hydroxyapatite complex versus calcium carbonate to prevent bone loss

Objective: This study aimed to compare the efficacy and safety of ossein-hydroxyapatite complex (OHC) versus calcium carbonate (CC) for preventing bone loss during perimenopause in current clinical practice.Methods: The prospective, comparative, non-randomized, open-label study included 851 perimenopausal women with basal bone mineral density (BMD) T-score ≥-2 standard deviations (SDs). Participants received either OHC (712 mg calcium/day) or CC (1000 mg calcium/day) over 3 years. BMD was evaluated by dual-energy X-ray absorptiometry at the lumbar spine (L2-L4) at baseline and after 18 and 36 months of follow-up. Adverse drug reactions (ADRs) were also recorded.Results: In women receiving OHC, BMD at the L2-L4 site remained stable over the 3-year follow-up period (mean [SD] change 0.00 [0.11] g/cm²). BMD in the CC arm decreased -3.1% (mean [SD] - 0.03 [0.11] g/cm²). Between-group differences were statistically significant (p < 0.001) and favored OHC. ADRs were more frequent in the CC group (7.7% vs. 2.7% in the OHC group; p = 0.001), affecting primarily the gastrointestinal system.Conclusion: OHC showed greater efficacy and tolerability than CC for bone loss prevention in perimenopausal women in real-world practice. As the daily dose of calcium was higher in the CC group, the differences might be linked to the ossein compound in OHC.

Acute and 3-month effects of microcrystalline hydroxyapatite, calcium citrate and calcium carbonate on serum calcium and markers of bone turnover: a randomised controlled trial in postmenopausal women

Ca supplements are used for bone health; however, they have been associated with increased cardiovascular risk, which may relate to their acute effects on serum Ca concentrations. Microcrystalline hydroxyapatite (MCH) could affect serum Ca concentrations less than conventional Ca supplements, but its effects on bone turnover are unclear. In the present study, we compared the acute and 3-month effects of MCH with conventional Ca supplements on concentrations of serum Ca, phosphate, parathyroid hormone and bone turnover markers. We randomised 100 women (mean age 71 years) to 1 g/d of Ca as citrate or carbonate (citrate-carbonate), one of two MCH preparations, or a placebo. Blood was sampled for 8 h after the first dose, and after 3 months of daily supplementation. To determine whether the acute effects changed over time, eight participants assigned to the citrate dose repeated 8 h of blood sampling at 3 months. There were no differences between the citrate and carbonate groups, or between the two MCH groups, so their results were pooled. The citrate-carbonate dose increased ionised and total Ca concentrations for up to 8 h, and this was not diminished after 3 months. MCH increased ionised Ca concentrations less than the citrate-carbonate dose; however, it raised the concentrations of phosphate and the Ca-phosphate product. The citrate-carbonate and MCH doses produced comparable decreases in bone resorption (measured as serum C-telopeptide (CTX)) over 8 h and bone turnover (CTX and procollagen type-I N-terminal propeptide) at 3 months. These findings suggest that Ca preparations, in general, produce repeated sustained increases in serum Ca concentrations after ingestion of each dose and that Ca supplements with smaller effects on serum Ca concentrations may have equivalent efficacy in suppressing bone turnover.

Use of ossein-hydroxyapatite complex in the prevention of bone loss: a review

BACKGROUND AND OBJECTIVE

The ossein-hydroxyapatite complex (OHC) is a microcrystalline form of calcium which provides a number of additional minerals (magnesium, phosphorus, potassium, zinc), and proteins (osteocalcin, type I collagen, type I insulin growth factor I and II, transforming growth factor beta) associated with bone metabolism. The objective of this review is to examine the role of OHC in preventing bone loss in different conditions.

MATERIAL AND METHODS

A review of clinical trials assessing the relationship between OHC and bone loss was made using the following data sources: Medline (from 1966 to December 2013), the Cochrane Controlled Clinical Trials Register, Embase (up to December 2013), contact with companies marketing the supplements studied, and reference lists.

RESULTS

Different randomized, clinical trials and meta-analysis suggest that OHC is more effective than calcium supplements in maintaining bone mass in postmenopausal women and in different conditions related to bone loss. In addition, OHC improves pain symptoms and accelerates fracture consolidation in patients with osteopenia or osteoporosis.

CONCLUSION

The ossein-hydroxyapatite complex is significantly more effective in preventing bone loss than calcium carbonate.

Nanohydroxyapatite application to osteoporosis management

Hydroxyapatite is chemically related to the inorganic component of bone matrix as a complex structure with the formula of Ca10(OH)2(PO4)6. Previous studies have reported the application of microsized hydroxyapatite to bone regeneration, but the result is not satisfied. The limitation comes from the size of hydroxyapatite. In addition, the duration of treatment is very long. The advantages of hydroxyapatite nanocrystal are the osteoconduction, bioresorption, and contact in close distance. Crystal in osteoporotic bone is calcium phosphate hydroxide with the chemical formula of Ca10(OH)2(PO4)6. Crystal of normal bone is sodium calcium hydrogen carbonate phosphate hydrate with the chemical formula of Ca8H2(PO4)6 ·H2O-NaHCO3-H2O. The recent development is applying nanobiology approach to hydroxyapatite. This is based on the concept that the mineral atoms arranged in a crystal structure of hydroxyapatite can be substituted or incorporated by the other mineral atoms. In conclusion, the basic elements of hydroxyapatite crystals, composed of atomic minerals in a certain geometric pattern, and their relationship to the bone cell biological activity have opened opportunities for hydroxyapatite crystals supplement application on osteoporosis. Understanding of the characteristics of bone hydroxyapatite crystals as well as the behavior of mineral atom in the substitution will have a better impact on the management of osteoporosis.

Comparison of the effects of ossein-hydroxyapatite complex and calcium carbonate on bone metabolism in women with senile osteoporosis: a randomized, open-label, parallel-group, controlled, prospective study

BACKGROUND AND OBJECTIVE

Calcium and vitamin D supplementation is recommended in patients with osteopenia and osteoporosis. One group that could benefit from this treatment is women with senile osteoporosis. Two sources of supplementary calcium are ossein-hydroxyapatite complex (OHC) and calcium carbonate, but, to date, their comparative effects on bone metabolism have not been studied in women with senile osteoporosis. The objective of this study was to compare the effects of OHC and calcium carbonate on bone metabolism in women with senile osteoporosis.

METHODS

This was a randomized, open-label, parallel-group, controlled, prospective study to compare the effects of OHC (treatment group) and calcium carbonate (control group) on bone metabolism. Patients were included between 2000 and 2004 and followed up for a maximum of 3 years. The study was carried out at the bone metabolism unit of two university hospitals in Barcelona, Spain. Subjects were women aged >65 years with densitometric osteoporosis of the lumbar spine or femoral neck. The treatment group received open-label OHC (Osteopor®) at a dose of two 830 mg tablets every 12 hours (712 mg elemental calcium per day). The control group received open-label calcium carbonate at a dose of 500 mg of elemental calcium every 12 hours (1000 mg elemental calcium per day). Both groups also received a vitamin D supplement (calcifediol 266 μg) at a dose of one vial orally every 15 days. Biochemical markers of bone remodelling (osteocalcin by electrochemiluminescence, tartrate-resistant acid phosphatase using colorimetry) were measured at baseline and annually for 3 years. Bone mineral density (BMD) at the lumbar spine and femoral neck was also measured.

RESULTS

One hundred and twenty women were included (55 in the OHC group and 65 in the calcium carbonate group), of whom 54 completed 3 years of follow-up. Levels of serum osteocalcin increased to a greater extent in the OHC group compared with the calcium carbonate group (by a mean ± SD of 0.84 ± 3.13 ng/mL at year 2 and 1.86 ± 2.22 ng/mL at year 3 in the OHC group compared with a mean ± SD decrease of 0.39 ± 1.39 ng/mL at year 2 and an increase of 0.31 ± 2.51 ng/mL at year 3 in the calcium carbonate group); the differences between treatment groups were statistically significant (p < 0.05) at both years. Changes over time in serum osteocalcin level were also statistically significant (p < 0.05) in the OHC group, but not in the calcium carbonate group. Changes in mean BMD at the lumbar spine and femoral neck between baseline and year 3 were -1.1% and 2.5% for OHC and -2.3% and 1.2% for calcium carbonate, respectively.

CONCLUSION

OHC had a greater anabolic effect on bone than calcium carbonate.

Long-term safety and efficacy of raloxifene in the prevention and treatment of postmenopausal osteoporosis: an update

The integrity of bone tissue and its remodeling that occurs throughout life requires a coordinated activity of osteoblasts and osteoclasts. The decreased estrogen circulating level during postmenopausal transition, with a prevalence of osteoclastic activity over osteoblastic activity, represents the main cause of bone loss and osteoporosis. Osteoporosis is a chronic disease requiring long-term therapy and it is important to evaluate the efficacy and safety of treatments over several years, as the fear of health risks is a common reason for discontinuing therapy. Raloxifene is a selective estrogen receptor modulator (SERM) leading to estrogen-agonist effects in some tissues and estrogen-antagonist effects in others. Raloxifene is effective to prevent and treat postmenopausal vertebral osteoporosis, with reduction of spine fractures and, in post-hoc analyses, non-spine fractures in high-risk subjects. Moreover, raloxifene reduces the risk of invasive breast cancer and improves the levels of serum lipoprotein but with an increased risk of venous thromboembolism and fatal stroke, without significant change in the incidence of coronary events. For these reasons the overall risk-benefit profile is favorable. Therefore, when considering the use of raloxifene in a postmenopausal woman, we should take into account the osteoporosis-related individual risk and weigh the potential benefits, skeletal and extra-skeletal, against the health risks.