Changes In Bone-specific Alkaline Phosphatase Research Articles

Ker-050 Treatment Reduced Iron Overload and Increased Bone Specific Alkaline Phosphatase in Participants with Lower-Risk MDS Supporting Potential to Restore Balance to the Osteohematopoietic Niche

Background: Iron overload (IO) in myelodysplastic syndromes (MDS) contributes to the deterioration of the osteohematopoietic niche (OHN), where hematopoietic and osteogenic precursors interact to regulate hematopoiesis and bone metabolism. Excess iron exacerbates ineffective hematopoiesis, inflammation, and bone loss via direct effects on resident hematopoietic and osteogenic precursors. Iron chelation therapy (ICT) is associated with improved event-free survival in patients with MDS but does not address the underlying cause of IO and introduces patient burden due to tolerability and cost. KER-050 is an investigational, modified activin receptor type IIA ligand trap designed to inhibit select TGF-β superfamily ligands (activins A, B, GDFs 8, 11) and promote differentiation and maturation of erythroid and megakaryocytic precursors. KER-050 has potential to reduce dependence on red blood cell transfusions and increase iron utilization via erythropoiesis, possibly mitigating IO at its source. As previously reported from an ongoing Phase 2 study (NCT04419649), KER-050 treatment in participants with lower-risk (LR) MDS resulted in rates of modified IWG 2006 Hematological Improvement-Erythroid (HI-E) and transfusion independence (TI) of 51.4% and 42.3%, respectively, with a mean decrease in ferritin (322 ng/mL at Week 24) among HI-E and/or TI responders. KER-050 treatment also demonstrated effects on osteogenic precursors, including prevention of bone loss in a mouse model of MDS and dose-dependent increases in bone specific alkaline phosphatase (BSAP), a marker of bone formation, observed in healthy postmenopausal women. Thus, KER-050 has potential to address the multifaceted pathogenesis of MDS, including IO. Here, we present new data from the ongoing Phase 2 study in MDS, exploring the potential of KER-050 to provide benefit beyond hematologic responses and to ameliorate IO in MDS. Methods: This ongoing Phase 2 study is evaluating KER-050 in participants with LR MDS. Data from exploratory assessments of markers of IO, hematopoiesis, and bone turnover are presented as of a cutoff date of April 3, 2023, for all participants who had received the recommended Part 2 dose (RP2D; 3.75-5 mg/kg q4wks). Results: Baseline ferritin levels in RP2D participants (N=59) were generally elevated, while levels of mean corpuscular hemoglobin and reticulocyte hemoglobin were in the normal range (Table 1). After KER-050 treatment, sustained decreases in serum ferritin were observed among participants with baseline levels ≥1000 ng/mL (Figure 1), likely driven in part by reduced transfusion burden in responders. Concomitant increases observed in soluble transferrin receptor (sTfR; Figure 1) suggest that increased erythropoiesis may also have contributed. Mean decreases in ferritin observed in non-transfused (NT) participants (-228 ng/mL at Week 24, n=7) indicate potential for KER-050 to affect iron homeostasis by mechanisms other than transfusion reduction. In 1 NT participant receiving ICT, the baseline ferritin of 1632 ng/mL decreased to <500 ng/mL over 32 weeks, leading to ICT discontinuation and coinciding with an increase in hemoglobin (Hgb) from 9.2 g/dL at baseline to 11.3 g/dL over the same period. In another NT participant not receiving ICT, ferritin decreased from 1094 ng/mL at baseline to 884 ng/mL and 583 ng/mL at Weeks 24 and 68, respectively, while Hgb gradually increased from 9.94 g/dL at baseline to 10.7 and 12.2 g/dL at Weeks 24 and 68. KER-050 treatment was also associated with increases in BSAP, a new finding in this MDS population that is consistent with prior observations in preclinical and healthy volunteer studies. Despite some heterogeneity, mean increases of 8.47% (n=23) and 10.4% (n=13) were observed at Weeks 24 and 48, respectively; 3 participants with erythroid responses had increases in BSAP of ≥30% at these time points. Summary: Exploratory data indicate potential for KER-050 to drive meaningful decreases in ferritin in participants with LR MDS, particularly among those with IO. While transfusion reduction likely contributes, observations in NT participants highlight the potential for enhancement of erythropoiesis to improve IO, irrespective of transfusions. Observed changes in BSAP suggest that KER-050 is also acting on osteogenic precursors, with the potential to provide functional improvements within the OHN. Updated results will be provided at the presentation.

Overview of the clinical efficacy and safety of eldecalcitol for the treatment of osteoporosis

SummaryEldecalcitol (ELD) is a new oral analog of the active form of vitamin D with anti-resorptive properties. We conducted a meta-analysis to investigate the efficacy and safety of ELD in osteoporosis. Compared with alfacalcidol, ELD significantly lowered vertebral facture risk, increased bone mineral density, but also had a higher risk of hypercalciuria.PurposeThis study aimed to investigate the efficacy and safety of eldecalcitol (ELD) in osteoporosis by examining fracture rates, bone mineral density (BMD), bone turnover markers, and adverse events as outcomes.MethodsPubMed, EMBASE, and Cochrane Library were searched up to July 20, 2020, to identify eligible randomized controlled trials. The odds ratio (OR) or weighted mean difference (WMD) with 95% confidence interval was calculated by the random-effects model.ResultsELD significantly increased lumbar BMD (WMD: 2.80; 95% CI: 1.60, 4.00; P < 0.001, 2 studies involved), total hip BMD (WMD: 2.11; 95% CI: 0.68, 3.55; P = 0.004, 2 studies involved), and femoral neck BMD (WMD: 1.78; 95% CI: 0.76, 2.79; P = 0.001, 1 study involved) compared with alfacalcidol. Moreover, ELD caused a significantly lower rate of vertebral fracture (OR: 0.52; 95% CI: 0.29–0.95; P = 0.034, 2 studies involved) than alfacalcidol, but did not lower the rate of non-vertebral facture (OR: 0.44; 95% CI: 0.06–3.05; P = 0.405, 2 studies involved) compared with alfacalcidol. ELD significantly reduced the percentage change in bone-specific alkaline phosphatase (WMD: − 15.40; 95% CI: − 20.30, − 10.60; P < 0.001, 1 study involved) and serum type I collagen C-telopeptide (WMD: − 38.50; 95% CI: − 50.00, − 27.10; P < 0.001, 1 study involved) as compared with alfacalcidol. ELD was also associated with higher risk of hypercalciuria compared with alfacalcidol (OR: 1.64; 95% CI: 1.22, 2.20; P = 0.001, 2 studies involved).ConclusionsThis systematic review indicated that ELD was superior than alfacalcidol for improving vertebral fracture risk and BMD. Further large-scale trials should be conducted to verify the long-term effects and safety of ELD in osteoporosis.Prospero registration numberCRD42020147518.

Predictive Power of Bone Turnover Biomarkers to Estimate Bone Mineral Density after Kidney Transplantation with or without Denosumab: A post hoc Analysis of the POSTOP Study

Background: Low bone mineral density (BMD) represents a major risk factor for bone fractures in patients with chronic kidney disease (CKD) as well as after kidney transplantation. However, modalities to solidly predict patients at fracture risk are yet to be defined. Better understanding of bone turnover biomarkers (BTMs) may close this diagnostic gap. This study strives to correlate BTMs to BMD in kidney transplant recipients. Methods: Changes in BTMs – procollagen type I N-terminal propeptide (P1NP), bone-specific alkaline phosphatase (BSAP), β-isomer of the C-terminal telopeptide of type I collagen, and urine deoxypyridinoline/Cr – at the time of transplant and 3 months were correlated to changes in BMD measured by dual-energy X-ray absorptiometry at the time of transplant, 6, and 12 months, respectively. Half of the collective was treated with denosumab twice yearly in addition to the standard treatment with calcium and vitamin D. Results: Changes in bone formation markers BSAP and P1NP within 3 months showed a significant negative correlation to changes in BMD at the hip within 6 months in denosumab-naïve patients. This correlation was abrogated by denosumab treatment. Conclusions: Changes in BSAP and P1NP showed promise in short-term prediction of BMD. We suggest further trials expanding on the knowledge of these BTMs with assessment of fracture risk, sequential measurements of BTMs within the first 6 months, and the additional use of computed tomography to assess BMD.

Controlled Pilot Study of High-Impact Low-Frequency Exercise on Bone Loss and Vital-Sign Stabilization in Adolescents With Eating Disorders

PurposeAdolescents with anorexia nervosa (AN) face an increased lifetime risk of bone fragility. This randomized controlled study examined the efficacy and safety of a high-impact activity program on markers of bone turnover and stabilization of vital signs (VSS). MethodsForty-one hospitalized adolescents with AN were randomly assigned to routine care or routine care plus 20 jumps twice daily. Bone markers were measured at baseline days 1–3 (T1), days 4–6 (T2), and days 7–9 (T3). The primary outcome was change in bone-specific alkaline phosphatase (BSAP) at T3 adjusted for BSAP and % median body mass index at T1. Secondary outcomes were serum N-telopeptide (NTX) and osteocalcin at T3. Safety was determined by comparing weight gain, time to VSS and length of stay for each group. ResultsBSAP, NTX, or osteocalcin did not differ between groups at baseline or at T3. BSAP and NTX at T3 were not associated with group of enrollment or % median body mass index. VSS was significantly reduced in the intervention group compared with the control group (11.6 ± 5.7 days vs. 17 ± 10.5 days, p = .049). There was no significant difference in weight gain or length of stay between groups. ConclusionsTwice-daily jumping activity failed to influence markers of bone turnover in adolescents with AN but was well tolerated, shortened time to vital-sign stabilization and did not slow weight gain.

Direct effects of physical training on markers of bone metabolism and serum sclerostin concentrations in older adults with low bone mass.

BackgroundBoth gravitational loading and the forces generated by muscle contraction have direct effects on serum markers of bone metabolism. The object of this study was to examine the direct effects of a single session of resistance exercise or walking on biochemical markers of bone metabolism in participants with low bone mass.MethodsA total of 150 otherwise healthy female subjects (mean age = 59.1 ± 7.1 years) diagnosed with osteoporosis or osteopenia were randomly allocated to either a resistance exercise group (RG; n = 50), walking group (WG; n = 50), or control group (CG; n = 50). Changes in bone-specific alkaline phosphatase (BALP), carboxy-terminal cross-linked telopeptide of type I collagen (CTX), and serum sclerostin concentrations were measured before and immediately after a single exercise intervention.ResultsThere was no significant change in BALP values in any of the groups. Sclerostin levels increased in the RG and WG, and there was significant difference between the WG and CG after the exercise intervention (P < 0.01). In contrast, the changes in CTX concentrations from baseline were significant in the RG (P < 0.01) but not in the WG (P = 0.11), and there was a significant difference between resistance exercise and walking (P < 0.01).ConclusionsIn participants with low bone mass, resistance exercise influenced the serum concentrations of CTX, a marker of bone resorption, but walking did not.Trial registrationCurrent Controlled Trials ISRCTN16329455; retrospectively registered on 05/05/2016.

Chondroprotective effects of zoledronic acid on articular cartilage in dogs with experimentally induced osteoarthritis

To assess effects of zoledronic acid on biomarkers, radiographic scores, and gross articular cartilage changes in dogs with induced osteoarthritis. 21 purpose-bred hound-type dogs. The left stifle joint of each dog was examined arthroscopically to determine initial articular cartilage status, which was followed by cranial cruciate ligament (CrCL) transection to induce osteoarthritis. Dogs were assigned to 3 groups (control group, low dose [10 μg of zoledronic acid/kg], or high dose [25 μg of zoledronic acid/kg). Treatments were administered SC every 3 months for 1 year beginning the day after CrCL transection. Serum and synovial fluid samples and radiographs were obtained 0, 1, 3, 6, 9, and 12 months after transection. At 12 months, each joint was scored for cartilage defects. Serum and synovial fluid biomarkers of bone and cartilage turnover (bone-specific alkaline phosphatase, type I and II collagen, carboxy-propeptide of type II collagen, and chondroitin sulfate 846) were analyzed with ELISAs. The high-dose group had fewer total articular defects and lower severity scores in CrCL-transected stifle joints than did the control group. In addition, the high-dose group had significantly less change in collagenase cleavage of type I or II collagen in the synovial fluid at 1 and 3 months after CrCL transection than did the control group and also had greater changes in bone-specific alkaline phosphatase in synovial fluid at 3 months after CrCL transection than did the control group. Zoledronic acid had a chondroprotective effect in dogs with a transected CrCL.

Changes in Bone Alkaline Phosphatase and Procollagen Type-1 C-Peptide After Static and Dynamic Exercises

We investigated the effects of two types of nonweight-bearing exercise on changes in bone-specific alkaline phosphatase (BAP) and procollagen type 1 C-peptide (P1P). BAP is a specific marker of bone synthesis, whereas P1P reflects synthesis of type 1 collagen in other organs as well as bone. Eight participants performed static and dynamic unilateral knee extensions. BAP and P1P were measured before, and at 1, 2, 24, 48, and 72 hr after exercise. P1P increased at 24 hr after a static knee extension exercise, whereas BAP did not change during the experimental period. We found no changes in these markers after dynamic exercise. These results imply that type 1 collagen synthesis in tendons increases after static exercise.

Plasma C‐type natriuretic peptide forms and thyroid status in prepubertal children with acquired thyroid disease

C-type natriuretic peptide (CNP) and thyroid hormone (TH) are essential for normal skeletal growth. Plasma CNP peptides correlate with growth velocity, but the relationship between thyroid status and CNP production is unknown. This study examined the impact of restoring normal TH levels on CNP and height velocity (HV) in children with acquired hypo- and hyperthyroidism. We performed a prospective, observational study in prepubertal children with acquired hypothyroidism (n = 15) and hyperthyroidism (n = 12). Blood levels of CNP, amino-terminal proCNP (NTproCNP), bone-specific alkaline phosphatase (BSAP), IGF-I and TH levels were measured before and during the first 6 months of standard treatment for hypo- and hyperthyroidism, and correlations were determined. At baseline, HV, CNP, NTproCNP and BSAP were significantly higher in hyper- than in hypothyroid subjects. Changes in TH after treatment were closely coupled to change in CNP and NTproCNP in hyperthyroid, but not in hypothyroid, children. In addition, a positive association of HV with CNP peptides was found during treatment of hyperthyroidism. Normalizing TH did not correlate with changes in BSAP or IGF-I in either group. Plasma CNP peptides are higher in children with hyperthyroidism than in those with hypothyroidism at diagnosis and, in hyperthyroid children, change concordantly with TH and HV during treatment. Differential responses of CNP in the two groups suggest CNP production is dependent on growth plate activity and not a direct effect of TH on CNP gene expression. Our findings suggest novel mechanisms underlying changes in skeletal response during treatment in children with acquired thyroid disease.

Long-term treatment with raloxifene, but not bisphosphonates, reduces circulating sclerostin levels in postmenopausal women

We determined whether suppression of sclerostin levels by estrogen treatment was mediated by anti-resorptive effect. Raloxifene, but not bisphosphonates, suppressed circulating sclerostin concentration, suggesting that sclerostin may mediate the action of estrogen on bone metabolism, independently of their anti-resorptive effects. Circulating sclerostin concentrations are higher in postmenopausal than in premenopausal women, and estrogen treatment suppresses sclerostin levels in both men and women. We determined whether anti-resorptives may suppress the circulating sclerostin levels. We conducted a retrospective observational study. Eighty postmenopausal women were treated with raloxifene for 19.4 ± 7.7 months (n = 16), bisphosphonates for 19.2 ± 6.7 months (n = 32), or were untreated (n = 32) for 17.1 ± 4.6 months. Plasma sclerostin concentrations were measured before and after treatment. Plasma sclerostin levels after treatment were significantly lower in the raloxifene than in the control group (55.8 ± 23.4 pmol/l vs. 92.1 ± 50.4 pmol/l, p = 0.046), but were similar between the bisphosphonate and control groups. Relative to baseline, raloxifene treatment markedly reduced plasma sclerostin concentration (-40.7 ± 22.8%, p < 0.001), with respect to both control (-7.5 ± 29.1%) and bisphosphonate (-3.1 ± 35.2%) groups. Changes in bone-specific alkaline phosphatase and osteocalcin levels showed reverse associations with sclerostin concentration changes in the raloxifene (γ = -0.505, p = 0.017) and control (γ = -0.410, p = 0.020) groups. Raloxifene, but not bisphosphonates, significantly suppressed circulating sclerostin concentration, suggesting that sclerostin may mediate the action of estrogen on bone metabolism, independently of their anti-resorptive effects.

The Effect of Soy Food Intake on Mineral Status in Premenopausal Women

Soy foods have been substituted for meat in recent years because of proposed health benefits. Research indicates, however, that soy protein and phytate in soy products inhibit the absorption of divalent cations. Our study was primarily designed to determine the effect of consuming two to three servings per day of soy foods, providing ∼19 g protein and ∼36 mg isoflavones, on iron and zinc status in premenopausal women during a 10-weeks period. As secondary outcomes, we also tested the effect of soy foods on biochemical markers of bone and thyroid hormones. Nonsmoking women (18-28 years) without chronic disease, anemia, pregnancy, or irregular menstrual cycles were randomly assigned to either the soy food (SF, n=31) or animal food (AF, n=32) group. Blood and urine samples and 3-day dietary records were collected at baseline and postintervention. At baseline, iron and zinc status, bone markers, and thyroid hormones were not different between groups. After intervention, no significant changes were observed in hemoglobin, transferrin saturation, serum iron, ferritin, or transferrin receptor (TFR) concentrations. Plasma zinc, but not serum alkaline phosphatase, significantly decreased in both groups (-0.8 μmol/L). The change in bone-specific alkaline phosphatase was significant between SF (1.5 U/L) and AF (-0.7 U/L) groups. No significant changes were observed in bone resorption, thyroid-stimulating hormone (TSH), or free thyroxine after soy food intake. Incorporating ∼19 g soy protein from soy foods for 10 weeks had no significant effect on iron or zinc status, bone resorption or formation, or thyroid hormone status in premenopausal women.

Relationship between 3-month changes in biochemical markers of bone remodelling and changes in bone mineral density and fracture incidence in patients treated with strontium ranelate for 3 years

From two randomised controlled trials, it is shown that 3-month changes in biochemical markers of bone formation (bone-specific alkaline phosphatase and C-terminal propeptide of type I procollagen) were associated with 3-year bone mineral density (BMD) changes, but not fracture incidence in patients treated with strontium ranelate. The purpose of this study was to assess if short-term change in biochemical markers of bone remodelling is associated with long-term BMD change and fracture incidence observed during treatment with strontium ranelate. From the SOTI and TROPOS trials, bone-specific alkaline phosphatase (BALP), C-terminal propeptide of type I procollagen (PICP), serum C-terminal telopeptides (S-CTX) and urine N-terminal telopeptides of type I collagen (U-NTX) were assessed at baseline and after 3 months. Two thousand three hundred seventy-three women were included in this study. Multiple regression analysis showed that 3-month changes in PICP and BALP but not s-CTX I nor s-NTX I were significantly (p < 0.001) associated with 3-year BMD changes at the lumbar spine and the femoral neck. Changes in s-CTX I, PICP and BALP were significantly associated with change in total proximal femur BMD. Changes in biochemical markers explain less than 8% of the BMD changes. The 3-month changes in BALP, PICP s-CTX I and s-NTX I were not significantly associated with fracture incidence. Short-term changes in biochemical markers of bone formation are associated with future BMD changes in patients treated with strontium ranelate, suggesting a bone-forming activity of this treatment, but are not appropriate to monitor the efficacy of strontium ranelate at the individual level.

Effect of Strontium Ranelate on Lumbar Spine Bone Mineral Density in Women with Established Osteoporosis Previously Treated with Teriparatide

Teriparatide (TPTD - recombinant human parathyroid hormone 1-34) markedly increases bone mineral density (BMD) and reduces fracture risk. Sequential treatment with an antiresorptive agent is believed to preserve or further increase BMD. Strontium ranelate (SR) is thought to uncouple bone remodeling resulting in increased BMD and reduced fracture risk. We aimed to evaluate the effect of SR on BMD in women with established osteoporosis previously treated with TPTD. Nineteen out of the consecutive 23 initially recruited postmenopausal Caucasian women (aged 65.9+/-1.8 years) with established osteoporosis completed treatment with TPTD, 20 microg daily for 18 months, followed by SR 2 g daily for 12 months. Lumbar spine BMD was measured by dual-energy X-ray absorptiometry (DXA) pre- and post-TPTD administration, as well as twelve months post-SR administration. Blood samples for bone-specific alkaline phosphatase (BSAP) and C-terminal telopeptide of type 1 collagen (CTx) were obtained at the same time points. Lumbar spine BMD increased significantly after 18 months of TPTD (p<0.001) and further improved with sequential SR treatment (p=0.033). Serum BSAP and CTx increased significantly with TPTD (p=0.008 and 0.017, respectively) and reduced to baseline levels after SR treatment (p=0.031 and 0.019, respectively). The change in BSAP was positively correlated with the change in CTx during both TPTD (r=0.641, p=0.007) and SR treatment (r=0.539, p=0.026). In conclusion, our data suggest that SR following TPTD administration further increases BMD and could represent an effective sequential treatment.

Bone-specific alkaline phosphatase (BSAP) and serum N-telopeptide (sNTX) as predictors of bone loss in postmenopausal women with early breast cancer receiving letrozole as adjuvant therapy: a 5-year study (Z-FAST).

Abstract Abstract #2067 Background: Changes in biochemical markers of bone turnover are expected to be predictors of long-term changes in bone mineral density (BMD). We studied the potential of bone-specific alkaline phosphatase (BSAP) and serum N-telopeptide (sNTX) at 6 and 12 months (mo) in predicting BMD of the lumber spine (LS) and total hip (TH) at 48 mo in Z-FAST study.&amp;#x2028; Methods: Postmenopausal women with ER+ and/or PR+ early stage breast cancer were randomized 1:1 into Up-front (U) or Delayed (D) arms (N=301 in each). Patients (pts) in U received zoledronic acid (ZOL) 4 mg IV q6 mo starting at baseline; pts in D started ZOL q6 mo when their LS or TH T-score fell below -2. All pts started Letrozole 2.5 mg/day for 5 years. Levels of BSAP and sNTX were assessed at screening and every 6 mo on a subset of pts. LS and TH BMD were assessed by dual-energy x-ray absorptiometry (DEXA) at screening, 6 mo and every 12 mo thereafter for all available pts. This is an exploratory analysis to investigate the correlation between short-term % changes from baseline in BSAP and sNTX and long-term % changes from baseline in BMD. Pearson correlations and Receiver Operating Characteristics (ROC) analysis were performed. We report the results based on 48 mo data.&amp;#x2028; Results: The Pearson correlations between % change in BSAP at 6 mo and LS BMD at 48 mo were -0.13 [(N=38, not significant (NS)] and -0.17 (N=39, NS) in arms U and D respectively. The correlations between % change in BSAP at 12 mo and LS BMD at 48 mo were -0.15 (N=39, NS) in U and -0.43 (N=38, p=0.0077) in D. Very similar correlations were obtained for % change in sNTX at 6, 12 mo and LS BMD at 48 mo in D, but in U the correlations were smaller and positive. The correlations between % change of both markers at 6, 12 mo and TH BMD at 48 mo were all NS at 0.05. ROC analysis showed that at best performance (maximum of sensitivity plus specificity), for any increase in sNTX at 12 mo, the sensitivity (SE), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) to predict LS BMD loss at 48 mo was 74%, 77%, 85% and 63% in D. For BSAP change of 3%, the four ROC parameters were 71%, 71%, 81% and 59% respectively. For prediction of TH BMD loss, the SE, SP and NPV were lower for both markers with higher PPV. In U, the SE, SP and PPV were all much lower with very high NPV for both markers and BMD loss.&amp;#x2028; Conclusion: Interim results of Z-FAST data show that short-term changes in BSAP and sNTX have the potential for predicting long-term bone loss. The weaker correlations in U also suggest that zoledronic acid may have a direct preventive effect on bone loss independent of changes in the markers. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2067.

Hip fracture protection by alendronate treatment in postmenopausal women with osteoporosis: a review of the literature.

Osteoporosis most commonly affects postmenopausal women, placing them at a significant risk of fractures. In particular, hip fractures are an important cause of mortality and morbidity among postmenopausal women. Anti-resorptive therapies that produce greater decreases in bone turnover markers together with greater increases in bone mineral density (BMD) are associated with greater reductions in fracture risk, especially at sites primarily composed of cortical bone such as the hip. Thus, treatment with potent anti-resorptive drugs like alendronate is a strategy for preventing hip fractures in postmenopausal women with osteoporosis. The purpose of this paper is to discuss the efficacy of alendronate against hip fractures and the mechanism for this anti-fracture efficacy in postmenopausal women with osteoporosis. A meta-analysis of randomized controlled trials has shown that alendronate reduces the risk of hip fractures by 55% in postmenopausal women with osteoporosis. According to the analyses of the Fracture Intervention Trial, each 1 standard deviation reduction in a 1-year change in bone-specific alkaline phosphatase (BSAP) is associated with 39% fewer hip fractures in alendronate-treated postmenopausal women, and those with at least 30% reduction in BSAP have a 74% lower risk of hip fractures relative to those with less than 30%. Alendronate is effective in reducing the risk of hip fractures across a spectrum of ages. The mechanism for this anti-fracture efficacy has been clarified; alendronate strongly suppresses bone turnover and subsequently increases hip BMD, decreases cortical porosity, improves parameters of hip structure geometry (cortical thickness, cross-sectional area, section modulus, and buckling ratio), and produces more uniform mineralization (increases the mean degree of mineralization of bone) in cortical bone. A once-weekly regimen of alendronate administration provides better patient compliance and persistence with the treatment than the once-daily dosing regimen, leading to greater efficacy against hip fractures. Thus, the efficacy of alendronate against hip fractures has been confirmed in postmenopausal women with osteoporosis, especially with a once-weekly dosing regimen.

Effects of alendronate and risedronate on bone mineral density and bone turnover markers in late postmenopausal women with osteoporosis

This study was undertaken to compare the effects of alendronate and risedronate on bone mineral density (BMD) and bone turnover markers (BTMs) in late postmenopausal women with osteoporosis. Thirty women older than 60 y of age were randomly assigned to receive alendronate 10 mg (n=16) or risedronate 5 mg (n=14) on a daily basis. The patients were followed every 3 mo for 12 mo. BMD measurements were taken at baseline and at the end of the study, and BTMs were measured at 3-mo intervals. By the end of the study, there were statistically significant increases in BMD in both groups at all sites at which they were measured (P<.001). However, these differences were not statistically significant between groups. By the end of the study, all BTMs had decreased significantly and to a similar extent in both groups. The most significant change was observed in the third month of the study. A negative correlation was noted between percentage change in bonespecific alkaline phosphatase and femoral neck BMD (r=-0.467). This study reported no difference between the 2 drugs in their effects on BMD and BTMs.