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R Rizzoli

Publications and source records attributed to R Rizzoli.

At least 37 records · Page 2Linked to original sources
PubMed2004

The need for clinical guidance in the use of calcium and vitamin D in the management of osteoporosis: a consensus report.

A European Union (EU) directive on vitamins and minerals used as ingredients of food supplements with a nutritional or physiological effect (2002/46/EC) was introduced in 2003. Its implications for the use of oral supplements of calcium and vitamin D in the prevention and treatment of osteoporosis were discussed at a meeting organized with the help of the World Health Organization (WHO) Collaborating Center for Public Health Aspects of Rheumatic Diseases (Liège, Belgium) and the support of the WHO Collaborating Center for Osteoporosis Prevention (Geneva, Switzerland). The following issues were addressed: Is osteoporosis a physiological or a medical condition? What is the evidence for the efficacy of calcium and vitamin D in the management of postmenopausal osteoporosis? What are the risks of self-management by patients in osteoporosis? From their discussions, the panel concluded that: (1) osteoporosis is a disease that requires continuing medical attention to ensure optimal therapeutic benefits; (2) when given in appropriate doses, calcium and vitamin D have been shown to be pharmacologically active (particularly in patients with dietary deficiencies), safe, and effective for the prevention and treatment of osteoporotic fractures; (3) calcium and vitamin D are an essential, but not sufficient, component of an integrated management strategy for the prevention and treatment of osteoporosis in patients with dietary insufficiencies, although maximal benefit in terms of fracture prevention requires the addition of antiresorptive therapy; (4) calcium and vitamin D are a cost-effective medication in the prevention and treatment of osteoporosis; (5) it is apparent that awareness of the efficacy of calcium and vitamin D in osteoporosis is still low and further work needs to be done to increase awareness among physicians, patients, and women at risk; and (6) in order that calcium and vitamin D continues to be manufactured to Good Manufacturing Practice standards and physicians and other health care professionals continue to provide guidance for the optimal use of these agents, they should continue to be classified as medicinal products.

Aged↗
PubMed2004

A new selective estrogen receptor modulator HMR-3339 fully corrects bone alterations induced by ovariectomy in adult rats.

The selective estrogen receptor modulator (SERM) raloxifene has been shown to reduce the risk of vertebral fracture, but without significant effect on nonvertebral fractures. However, there is a need for SERMs capable of improving mechanical competence and reducing the risk of fractures at multiple skeletal sites, with minimal side effects. We investigated the effects of a new steroidal SERM, HMR-3339, compared to raloxifene, on bone strength and its determinants (BMD, microarchitecture, dimensions) at various skeletal sites (lumbar spine, tibia, and femur) of adult ovariectomized rats in both prevention and intervention protocols. In a prevention study, HMR-3339 and raloxifene treatments fully prevented alterations of bone strength. In an intervention protocol, where treatment was started 8 weeks after ovariectomy, HMR-3339 fully restored mechanical properties by influencing both areal BMD and outer diameter. This effect was observed at skeletal sites formed of cancellous and cortical bone or of cortical bone only. In contrast, raloxifene positively influenced structures containing mainly cancellous bone. In HMR-3339-treated rats, IGF-I plasma levels were higher than in ovariectomized controls; this was not observed with raloxifene. In conclusion, these results indicate that HMR-3339 increased not only bone mineral mass, but also restored bone mechanical strength at multiple sites in adult osteoporotic rats. In contrast to raloxifene, HMR-3339 also influenced skeletal sites predominantly formed of cortical bone.

Animals↗
PubMed2004

Upper gastrointestinal and overall tolerability of alendronate once weekly in patients with osteoporosis: results of a randomized, double-blind, placebo-controlled study.

OBJECTIVE: To compare the upper gastrointestinal (GI) and overall tolerability profiles of alendronate 70 mg once weekly with placebo. RESEARCH DESIGN AND METHODS: This 12-week international, multi-center, randomized, double-blind, placebo-controlled trial included 449 postmenopausal women and men with osteoporosis at 44 sites in 19 countries in Europe, the Americas, Africa, and Asia-Pacific. Subjects were randomized to alendronate 70 mg once weekly or matching placebo in a 1:1 ratio. MAIN OUTCOME MEASURES: The safety and tolerability of weekly alendronate and placebo were captured as clinical and laboratory adverse events. The primary endpoint was upper GI tolerability based on the incidence of upper GI tract adverse events. Secondary endpoints included the percentage of subjects who discontinued therapy due to a drug-related upper GI adverse event. Change from baseline in bone turnover as measured by the urinary N-telopeptide-collagen crosslinks corrected for creatinine (NTx/Cr) was assessed at 12 weeks as an indicator of efficacy. RESULTS: The percentages of subjects reporting an upper GI tract adverse event in the alendronate 70 mg once weekly group (9.8%) and the placebo group (9.4%) were similar. The risk difference between the two treatment groups (alendronate minus placebo) was 0.4% [95% confidence interval (CI), -5.1%, 5.9%]. Percentages of subjects who discontinued due to a drug-related upper GI adverse event were also similar (alendronate 2.7%; placebo 2.2%; risk difference 0.4%, 95% CI, -2.4, 3.3). The overall tolerability profile of alendronate 70 mg once weekly, as measured by the percentage 8.0% (95% CI, 1.4%, 15.0%) increase in the of subjects reporting any adverse event, was similar to that of placebo (risk difference 2.1%, 95% CI -6.9, 11.0). There was a significant 43.3% (95% CI, -47.9%, -38.3%) decrease from baseline in urinary NTx/Cr in the alendronate group compared with an placebo group at Week 12. CONCLUSION: Alendronate 70 mg administered once weekly to women and men with osteoporosis has an upper GI and overall tolerability profile similar to that of placebo.

Administration, Oral↗
PubMed2004

Functional importance of Myc-associated zinc finger protein for the human parathyroid hormone (PTH)/PTH-related peptide receptor-1 P2 promoter constitutive activity.

The aim of the present study was to analyze the functional importance for the parathyroid hormone (PTH)/PTH-related peptide (PTHrP) receptor (PTHR1) gene P2 promoter activity of the putative proximal Myc-associated zinc finger protein (MAZ) site localized at position bp -45 to -39 bp, taking advantage of a G/A mutation identified at position -40 in the human sequence. Wild-type 'full-length' (1285P2) and truncated (760P2) promoter sequences were inserted upstream to the luciferase basic (pLucB) and enhancer (pLucE) reporter gene expression vectors. Transient transfections in osteoblast-like SaOS-2 cells and renal cells (RC.SV3A2) showed that the -40 G/A mutation significantly impaired transcriptional activity of wild-type 1285P2-pLucB and 760P2-pLucE promoter constructs. Further truncation of the P2 sequence demonstrated that the sequence -109/-37 bp was essential for promoter activity. Co-transfection with a MAZ expression vector did not modify the wild-type 1285P2-pLucB construct reporter activity but significantly increased 2-fold the mutated construction activity (P<0.05). Electrophoretic mobility shift assays using SaOS-2 nuclear extracts and a double-stranded DNA fragment encompassing the -45 to -39 putative MAZ site (ds-MAZ-oligo) disclosed two specific DNA-protein complexes. Complex II (fast moving) had a lower affinity for the mutated MAZ motif than for the wild-type MAZ motif while complex I (slow moving) had the same affinity for both wild-type or mutated MAZ sequences. Competition studies with Sp1 consensus oligonucleotide (ds-Sp1-oligo) markedly reduced complex I intensity, with a concomitant increase in that of complex II. Finally, ribonuclease protection assays showed that P2-specific PTHR1 mRNA transcript expression was significantly decreased in SaOS-2 cells transfected with ds-MAZ-oligo as compared with that for control (P<0.001) and ds-Sp1-oligo (P<0.05). Taken together, our studies suggest that the putative -45 to -39 MAZ-binding site regulates the constitutive activity of human PTHR1 P2 promoter.

Cell Nucleus↗
PubMed2003

Efficacy and safety of ibandronate in the treatment of hypercalcemia of malignancy: a randomized multicentric comparison to pamidronate.

GOALS: To compare the efficacy and safety of ibandronate and pamidronate in patients with hypercalcemia of malignancy (HCM). PATIENTS AND METHODS: Seventy-two patients with HCM [albumin-corrected serum calcium (CSC) >2.7 mmol/l] were treated with a single infusion of ibandronate (2 or 4 mg) or pamidronate (15, 30, 60, or 90 mg) on day 0. The dose was dependent on the severity of hypercalcemia (baseline CSC level). CSC was assessed daily until day 4, then at intervals until day 28. The primary endpoint was lowering of CSC at day 4. Secondary endpoints included the number of patients responding and time to re-increase following response. MAIN RESULTS: Using the CSC baseline approach, the most frequently administered doses were 4 mg ibandronate (78.4%) and 60 mg pamidronate (50.0%). Mean lowering of CSC at day 4 was 0.6 mmol/l for ibandronate and 0.41 mmol/l for pamidronate. The 95% confidence interval for the difference ibandronate pamidronate had a lower limit of 0.05 mmol/l, indicating that ibandronate was as effective as pamidronate. The number of patients responding to the two agents was also similar; 76.5% of ibandronate patients and 75.8% of pamidronate patients were rated as responders after the first dose of study medication. The median time to re-increase after response was longer for ibandronate (14 days) than pamidronate (4 days) ( P=0.0303). In the subgroup of 17 patients with high baseline CSC (>3.5 mmol/l), ibandronate appeared to be more effective than pamidronate. The safety profile of both agents was similar. CONCLUSIONS: Ibandronate is at least as effective as pamidronate in the treatment of HCM. Furthermore, in patients with higher baseline CSC ibandronate appears to be more effective than pamidronate. The duration of response is significantly longer with ibandronate than pamidronate.

Administration, Oral↗
PubMed2003

Bone strength and its determinants.

Osteoporosis is a disease defined by decreased bone mass and alteration of microarchitecture which results in increased bone fragility and increased risk of fracture. The major complication of osteoporosis, i.e., fracture, is due to a lower bone strength. Thus, any treatment of osteoporosis implies an improvement in bone strength. Bone strength is determined by bone geometry, cortical thickness and porosity, trabecular bone morphology, and intrinsic properties of bony tissue. Bone strength is indirectly estimated by bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA). Since DXA-measured BMD accounts for 60-70% of the variation in bone strength, some important factors are not captured by DXA in the progression of osteoporosis and the effects of antiosteoporotic treatment. Geometry and trabecular microarchitecture have also to be taken into account. Thus, the assessment of intrinsic mechanical quality of bony tissue should provide a better understanding of the role of tissue quality in determining bone strength. The careful investigation of all the determinants of bone strength (bone tissue included) should be considered in the pathophysiology of osteoporosis and in the mechanisms of action of antiosteoporotic drugs.

Biomechanical Phenomena↗
PubMed2003

A comprehensive review of treatments for postmenopausal osteoporosis.

The aim of this review is to assess the efficacy of treatments for postmenopausal osteoporosis in women with low bone mass or with an existing vertebral fracture. We searched the literature for studies (randomized, double-masked, placebo-controlled and prospective) that reported on drugs registered in Europe or North America. We included 41 reports on 12 agents. To assess the consistency among the studies for each drug, we plotted the percent change in bone mineral density (BMD) for the control group against the percent change in BMD for the treated group for lumbar spine and femoral neck. We used methods of cluster analysis to determine consistency among the studies. For each agent we summarized the relative risk for vertebral fracture (patients with new fracture) and for hip fractures. The duration of the studies ranged from 1 to 4.3 years. The proportion of patients who discontinued treatment ranged from 4% to 80%. Most of the studies reported on change in BMD. Twenty-six studies (10 drugs) provided data on new vertebral fractures and 12 (6 drugs) on hip fractures. Apart from fluoride effects on spine BMD, increases in BMD with bisphosphonates were greater than those seen with the remaining treatments. Generally, for each agent the changes in BMD (relative to placebo) were consistent among the studies. The exceptions were calcitriol and calcitonin for changes in BMD of the spine and of the femoral neck. Alendronate, calcitonin, risedronate and raloxifene caused significant reductions in the risk of vertebral fractures. Alendronate, risedronate or the combination of calcium plus vitamin D had a significant effect on the risk of hip fracture. Most therapies are effective in increasing BMD; some decrease the risk of vertebral fracture. For hip fracture, alendronate and risedronate reduce the risk in women with osteoporosis, and calcium and vitamin D reduce the risk in institutionalized patients.

Aged↗
PubMed2003

Comparison of three bone ultrasounds for the discrimination of subjects with and without osteoporotic fractures among 7562 elderly women.

UNLABELLED: Bone ultrasound measures (QUSs) can assess fracture risk in the elderly. We compared three QUSs and their association with nonvertebral fracture history in 7562 Swiss women 70-80 years of age. The association between nonvertebral fracture was higher for heel than phalangeal QUS. INTRODUCTION: Because of the high morbidity and mortality associated with osteoporotic fractures, it is essential to detect subjects at risk for such fractures with screening methods. Because quantitative bone ultrasound (QUS) discriminated subjects with osteoporotic fractures from controls in several cross-sectional studies and predicted fractures in prospective studies, QUS could be more practical than DXA for screening. MATERIAL AND METHODS: This cross-sectional and retrospective multicenter (10 centers) study was performed to compare three QUSs (two heel ultrasounds: Achilles+ [GE-Lunar] and Sahara [Hologic]; the phalanges: ultrasound DBM sonic 1200 [IGEA]) for determining by logistic regression nonvertebral fracture odds ratio (OR) in a sample of 7562 Swiss women, 75.3 +/- 3.1 years of age. The two heel QUSs measured the broadband ultrasound attenuation (BUA) and the speed of sound (SOS). In addition, Achilles+ calculated the stiffness index (SI) and the Sahara calculated the quantitative ultrasound index (QUI) from BUA and SOS. The DBM sonic 1200 measured the amplitude-dependent SOS (AD-SOS). RESULTS: Eighty-six women had a history of a traumatic hip fracture after the age of 50, 1594 had a history of forearm fracture, and 2016 had other nonvertebral fractures. No fracture history was reported by 3866 women. Discrimination for hip fracture was higher than for the other nonvertebral fractures. The two heel QUSs had a significantly higher discrimination power than the QUSs of the phalanges, with standardized ORs, adjusted for age and body mass index, ranging from 2.1 to 2.7 (95% CI = 1.6, 3.5) compared with 1.4 (95% CI = 1.1, 1.7) for the AD-SOS of DBM sonic 1200. CONCLUSION: This study showed a high association between heel QUS and hip fracture history in elderly Swiss women. This could justify integration of QUS among screening strategies for identifying elderly women at risk for osteoporotic fractures.

Age Factors↗
PubMed2002

Is time since hip fracture influencing the discrimination between fractured and nonfractured subjects as assessed at the calcaneum by three technologically different quantitative ultrasound devices?

Because quantitative ultrasound (QUS) instruments from different manufacturers have significant technical differences, it is difficult to assess whether all of them can discriminate similarly between osteoporotic fractures and age-matched controls. Thus, to avoid any bias, reliable comparative assessment of the QUS devices should be carried out on the same population. Few studies have fulfilled this condition. Another source of variability in cross-sectional studies in which fractured and nonfractured subjects are compared is the time since osteoporotic fracture. Our study evaluated the ability of three calcaneal QUS devices to discriminate patients with osteoporotic hip fracture from control subjects, using the same population. In addition, a subset of patients was re-measured about 9 months after the hip replacement surgery to check how the time since fracture affects the discriminatory ability of the different QUS devices. Fifty postmenopausal hip-fractured patients and 46 postmenopausal age-matched controls were included in this study and measured on three QUS devices, as well as 50 young healthy controls to calculate the T-score. Odds ratio results showed that a decrease in UBIS trade mark BUA of 1 SD was associated with a significant increase in fracture risk (odds ratio adjusted = 2.30) comparable with Sahara broadband ultrasound attenuation (BUA) (OR adj. = 2.30), and Achilles BUA (OR adj. = 3.5). However, given the large overlap between the 95% intervals of each OR and for the areas under ROC curves, no significant difference was found between them. In the subset of 15 hip-fractured subjects, no significant differences were found between ultrasound parameters of the first visit and 9 months after except for the heel width (soft tissue variation). Odds ratio and areas under the curve (AUC) tend to increase from visit 1 to 2 for the BUA and decrease substantially for the SOS for all but the Lunar Achilles+. Nonsignificant correlation was found between the absolute difference of the ultrasound parameters measured at the two visits and the time since fracture, except for the Sahara SOS (r = 0.45; P < 0.04). In conclusion, no significant differences between QUS technologies were observed in their positive and significant ability to discriminate hip-fractured patient from controls. However, this statement is shadowed when taking into account the time since fracture which seems to negatively influence results obtained on dry versus wet QUS systems. As a result, it is advisable that such parameters would be taken into account when designing a study aimed to demonstrate the discriminatory ability of heel ultrasound between normal and hip-fractured patients.

Adult↗
PubMed2002

Evaluation of the age-adjusted incidence of hip fractures between urban and rural areas: the difference is not related to the prevalence of institutions for the elderly.

As many as 40% of hip fractures occur in institutions for the elderly. Several studies have demonstrated a higher age-adjusted incidence of hip fractures in urban areas compared with rural areas. To assess whether this difference could be due to a preferential location of institutions for the elderly in urban areas, we compared the incidence of hip fractures over a 5-year period in urban versus rural areas, as defined according to the population density (urban > 15 inhabitants/ha2). We then determined the age-adjusted incidence of hip fractures in institutional-dwelling elderly and home-dwelling elderly. Hip fracture incidence was 100.0/100,000 (150.5 in women and 43.8 in men) in urban areas, and 71.0/100,000 (107.2 in women and 32.8 in men) in rural areas (p<0.001). When only those patients living in their own homes were analyzed, the incidence was 66.7/100000 (94.6 in women and 35.7 in men) in urban regions and 36.8/100,000 (49.6 in women and 23.4 in men) in rural areas (p<0.001), a difference of even greater magnitude than when both home-dwelling and institutional-dwelling residents were considered together. In a logistic regression model including age class, gender, urban or rural areas and institutionalization for inhabitants 65 years of age and older, urban residents have a 31% significantly (p<0.001) higher incidence of hip fracture compared with rural residents; women have a 79% significantly (p<0.001) higher incidence of hip fracture compared with men; and institutional-dwelling elderly have a 351% significantly (p<0.001) higher incidence of hip fracture compared with home-dwelling elderly. These results confirm the existence of a higher age-adjusted incidence of hip fractures in urban compared with rural areas. Since this difference is increased when patients living at home were analyzed separately, it indicates that the difference between urban and rural areas is not due to a preferential urban location of institutions for the elderly.

Age Distribution↗
PubMed2002

An osteoporosis clinical pathway for the medical management of patients with low-trauma fracture.

Patients with an osteoporotic fracture have at least a 2-fold risk for additional fracture and should benefit from targeted diagnostic and treatment procedures for osteoporosis. To address this issue, we set up an osteoporosis clinical pathway (OCP) for the medical management of patients with low-trauma fracture. Following acute management of the fracture by the orthopedic team, patients are enrolled in the pathway, which is based on an interaction between the OCP multidisciplinary team, orthopedic surgeons and/or primary care physicians. After collection of patient data, suggestions for additional diagnostic examinations with their interpretation, and treatment proposals are made. Patients and their families are also invited to attend a multidisciplinary interactive educational program on physical therapy, lifestyle habits and nutrition. During a 36-month period, 385 patients (311 women, 74 men; mean age +/- SD: 73.0 +/- 13.5 years; hip fracture 45%, ankle/tibia 24%, proximal humerus 8.6%, spine 5.5%, pelvis 3.9%, distal forearm 3.6%, other sites 17.4%) were enrolled in the OCP. An osteoporosis awareness questionnaire administered within 10 days of fracture showed that 73% of patients believed that their fracture was not related to the disease. Dual-energy X-ray absorptiometry, performed in 63% of patients, showed that 86% had low bone mass or osteoporosis. Specific antiosteoporotic therapy was proposed for 33% of patients in addition to calcium and vitamin D supplements, the latter suggested for 93%. A survey performed in 216 patients 6 months later, indicated that 63% of the suggested treatments had been prescribed and that 67% of this group were continuing treatment. Such a clinical pathway for the medical management of low-trauma fracture can help to identify patients with osteoporosis in a high-risk population, provide support to the orthopedic surgeon and/or the primary care physician for diagnostic and treatment procedures, and should significantly contribute to increase awareness of the disease in patients and their families.

Accidental Falls↗
PubMed2002

Survival and potential years of life lost after hip fracture in men and age-matched women.

Hip fracture is associated with a higher mortality rate in men than in women. However, mean age of men and women with hip fracture differs markedly. Thus, some of the differences in the clinical pattern and outcome between genders could be related to different ages. To avoid the influence of age on gender-specific outcome, we analyzed prefracture conditions and hip fracture outcome in a cohort of men and of age-matched women. Risk factors for low bone mass were recorded in 106 men (mean age +/- SD, 80.3 +/- 9.3 years) and 264 age-matched women (mean age 81.4 +/- 8.0) with hip fracture. We compared mortality rate, survival, years of potential life lost and modification of housing conditions. These outcomes were prospectively assessed during an average 3.6 years follow-up (up to 7 years). Men with hip fracture differed from age-matched hip-fractured women by a higher alcohol and tobacco consumption, a greater frequency of living in couple, and by less prevalent fractures. Mortality rate after hip fracture was significantly higher in men (RR = 1.74, 95% CI 1.34-2.24). Since mortality is higher in the general male population, we compared reduction in life expectancy taking into account the gender-specific mortality rate. The excess mortality in each age-group of hip-fractured patients, which was measured during the whole follow-up period, and is an estimate of death attributable to fracture, did not differ between genders. Reduction in life expectancy due to hip fracture was similar in both genders (5.9 +/- 4.5 and 5.8 +/- 4.8 years, in men and women, respectively; NS), but the proportion of the years of life lost was higher in men (70 +/- 33%) than in women (59 +/- 42%, p < 0.01). It was concluded that for the same age, mortality rate after hip fracture was higher in men than in women. Although the reduction in life expectancy was similar in both genders, the proportion of the years of life lost was higher in men, suggesting a worse impact of hip fracture on survival in men, even after consideration of the higher mortality rate in the general male population.

Aged↗
PubMed2002

Recovery of proximal tibia bone mineral density and strength, but not cancellous bone architecture, after long-term bisphosphonate or selective estrogen receptor modulator therapy in aged rats.

Various bisphosphonates and the selective estrogen receptor modulator (SERM) raloxifene are approved treatments of postmenopausal osteoporosis. They increase bone mineral density (BMD), decrease bone turnover, and reduce vertebral fracture incidence through different cellular mechanisms. We investigated the bone cellular activities, architecture, mineral content/density, and strength of ovariectomized (ovx) rats on a long-term bisphosphonate or SERM treatment, at doses of either agent correcting bone strength. Eleven weeks postovariectomy, 6-month-old rats were treated with the SERM MDL 103,323 or with the bisphosphonate pamidronate for 5 months. Doses of pamidronate and MDL 103,323 were selected from previous studies showing correction of the ovx-induced decrease of ultimate strength of proximal tibia. Ultimate and yield strengths, BMD, and histomorphometric parameters were all quantified at the same site, i.e., the proximal tibia metaphysis. Long-term pamidronate decreases bone turnover and bone formation activity, leading to trabecular thinning. MDL 103,323 decreases bone turnover to a lesser extent, and slightly protects trabecular architecture by uncoupling bone resorption and formation activities. The yield strength is corrected by pamidronate, but not by MDL 103,323 treatment. However, neither compound restores the ovariectomy-induced cancellous bone loss. Total tissue area and cortical thickness are unchanged with pamidronate or MDL 103,323 treatment, indicating that cortical bone mass, thickness, and cross-sectional area are not modified. The discrepancy between proximal tibia BMD and mechanical resistance to fracture modifications, on the one hand, and cancellous bone volume, on the other hand, could be due to changes in the degree of mineralization of bone matrix and/or of the intrinsic properties of the bone matrix.

Aging↗
PubMed2002

Two-year results of once-weekly administration of alendronate 70 mg for the treatment of postmenopausal osteoporosis.

The aim of this study was to provide confirmation that once-weekly dosing with 70 mg of alendronate (seven times the daily oral dose) and twice-weekly dosing with 35 mg is equivalent to the 10-mg once-daily regimen and to gain more extensive safety experience with this new dosing regimen. Twelve hundred fifty-eight postmenopausal women (aged 42-95 years) with osteoporosis (bone mineral density [BMD] of either lumbar spine or femoral neck at least 2.5 SDs below peak young adult mean or prior vertebral or hip fracture) were assigned to receive oral once-weekly alendronate, 70 mg (n = 519); twice-weekly alendronate, 35 mg (n = 369); or daily alendronate 10 mg (n = 370) for a total of 2 years of double-blind experience. Mean BMD increases from baseline (95% CI) at 24 months in the once-weekly, twice-weekly, and daily treatment groups, respectively, were 6.8% (6.4, 7.3), 7.0% (6.6,7.5), and 7.4% (6.9,7.8) at the lumbar spine and 4.1% (3.8,4.5), 4.3% (3.9,4.7), and 4.3% (3.9,4.7) at the total hip. These increases in BMD as well as the BMD increases at the femoral neck, trochanter, and total body and the reductions of biochemical markers of bone resorption (urinary cross-linked N-telopeptides of type I collagen [NTx]) and bone formation (serum bone-specific alkaline phosphatase [BSAP]) were similar for the three dosing regimens. All treatment regimens were well tolerated with a similar incidence of upper gastrointestinal (GI) adverse experiences. The incidence rates of clinical fractures, captured as adverse experiences, were similar among the groups. The 2-year results confirm the conclusion reached after 1 year that once-weekly alendronate is therapeutically equivalent to daily dosing, providing patients with a more convenient dosing option that may potentially enhance adherence to therapy.

Adult↗
PubMed2002

Dietary essential amino acid supplements increase bone strength by influencing bone mass and bone microarchitecture in ovariectomized adult rats fed an isocaloric low-protein diet.

This study was designed to investigate whether the administration of dietary essential amino acid supplements in adult rats made osteoporotic by estrogen deficiency and reduced protein intake could reverse the deleterious effects caused by these maneuvers. This animal model was selected to mimic the situation observed in elderly women in whom estrogen deficiency and/or low-protein intake (but also calcium and vitamin D deficiency) are known to contribute to the pathogenesis of osteoporosis. Six-month-old rats were ovariectomized (OVX) and fed an isocaloric 2.5% casein diet for 10 weeks or sham-operated (SHAM) and fed an isocaloric 15% casein diet. The animals fed the 2.5% casein diet were given isocaloric supplements of essential amino acids in similar relative proportion to that of casein at doses of 2.5% or 5% of total diet for an additional 16 weeks. Vertebrae, femur, and tibia bone mineral density (BMD); ultimate strength; and microtomographic histomorphometry were evaluated before and after dietary essential amino acid supplements. Essential amino acid supplements increased vertebrae, femur, and tibia bone strength in OVX rats fed a low-protein diet. The mechanical changes induced by this dietary isocaloric supplement were associated with the prevention of a further BMD decrease or even with some increases and changes in microarchitecture such as from a rod to a plate trabecular spacial configuration and increased cortical thickness. Higher insulin-like growth factor (IGF) I levels, as well as greater bone formation and reduced bone resorption as assessed by biochemical markers of bone remodeling, were found in rats receiving essential amino acid supplements. In conclusion, dietary essential amino acid supplements increased bone strength through modifications of BMD, trabecular architecture, and cortical thickness possibly by an IGF-I-mediated process.

Amino Acids, Essential↗
PubMed2002

Quality controls for two heel bone ultrasounds used in the Swiss Evaluation of the Methods of Measurement of Osteoporotic Fracture Risk Study.

Because of the important morbidity and mortality associated with osteoporosis, it is essential to detect subjects at risk by screening methods, such as bone quantitative ultrasounds (QUSs). Several studies showed that QUS could predict fractures. None, however, compared prospectively different QUS devices, and few data of quality controls (QCs) have been published. The Swiss Evaluation of the Methods of Measurement of Osteoporotic Fracture Risk is a prospective multicenter study that compared three QUSs for the assessment of hip fracture risk in a population of 7609 women age >/=70 yr. Because the inclusion phase lasted 20 mo, and because 10 centers participated in this study, QC became a major issue. We therefore developed a QC procedure to assess the stability and precision of the devices, and for their cross-calibration. Our study focuses on the two heel QUSs. The water bath system (Achilles+) had a higher precision than the dry system (Sahara). The QC results were highly dependent on temperature. QUS stability was acceptable, but Sahara must be calibrated regularly. A sufficient homogeneity among all the Sahara devices could be demonstrated, whereas significant differences were found among the Achilles+ devices. For speed of sound, 52% of the differences among the Achilles+ was explained by the water s temperature. However, for broadband ultrasound attenuation, a maximal difference of 23% persisted after adjustment for temperature. Because such differences could influence measurements in vivo, it is crucial to develop standardized phantoms to be used in prospective multicenter studies.

Calcaneus↗