3D-DXA Based Finite Element Modelling for Femur Strength Prediction: Evaluation Against QCT.

Osteoporosis is characterised by the loss of bone density resulting in an increased risk of fragility fractures. The clinical gold standard for diagnosing osteoporosis is based on the areal bone mineral density (aBMD) used as a surrogate for bone strength, in combination with clinical risk factors. Finite element (FE) analyses based on quantitative computed tomography (QCT) have been shown to estimate bone strength better than aBMD. However, their application in the osteoporosis clinics is limited due to exposure of patients to increased X-rays radiation dose. Statistical modelling methods (3D-DXA) enabling the estimation of 3D femur shape and volumetric bone density from dual energy X-ray absorptiometry (DXA) scan have been shown to improve osteoporosis management. The current study used 3D-DXA based FE analyses to estimate femur strength from the routine clinical DXA scans and compared its results against 151 QCT based FE analyses, in a clinical cohort of 157 subjects. The linear regression between the femur strength predicted by QCT-FE and 3D-DXA-FE models correlated highly (coefficient of determination R2 = 0.86) with a root mean square error (RMSE) of 397 N. In conclusion, the current study presented a 3D-DXA-FE modelling tool providing accurate femur strength estimates noninvasively, compared to QCT-FE models.

Is vitamin-D supplementation not useful in patients at risk of fractures and falls?

To evaluate numerous publications that question the bone and extraosseous benefits of vitamin D diet supplementation based on results, which often transcend to public opinion, but are not well interpreted. This may have negative consequences on compliance of patients under vitamin D supplementation. Critical appraisal of several articles on vitamin D supplementation and its relationship with fractures, falls, cardiovascular diseases, and cancer incidence. Such publications have certain limitations (i.e. patients excluded because of a diagnosis of osteoporosis, or at a higher risk for fractures and falls, or because they have a vitamin D deficiency, etc.), and conclusions and/or subsequent recommendations should be approached with caution. Our research shows that patients with osteoporosis, vitamin D deficiency, and at high risk of fractures and falls should not discontinue vitamin D supplementation (often associated with calcium). It is becoming increasingly evident that patients with hypovitaminosis D are those that gain a maximal benefit from vitamin D supplementation.

High Serum Retinol as a Relevant Contributor to Low Bone Mineral Density in Postmenopausal Osteoporotic Women.

There is controversial information about the impact of vitamin A on bone. Some epidemiological studies show that excessive intake of vitamin A, or an excess of serum vitamin A, has related with adverse impact on bone mass; however, other studies did not find these links, and some authors have proposed that this vitamin might promote a better bone health. The present work aims to contribute to clarify the real role of vitamin A in bone tissue. For this purpose, a cross-sectional study of 154 osteoporotic non-treated postmenopausal women (> 65 years old) was carried out. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. We assessed concentrations of serum retinol, osteocalcin, parathyroid hormone, alkaline phosphatase, calcium, and phosphorus. We also studied demographic and anthropometric parameters. Spearman's correlations between retinol levels and other variables found negative correlations with BMD in both lumbar spine (R = - 0.162, P < 0.01) and femoral neck (R = - 0.182, P < 0.01), as well as alkaline phosphatase (R = - 0.110; P < 0.05) and phosphorus (R = - 0.110; P < 0.05). A positive correlation between retinol and fertile window was observed (R = 0.158; P < 0.01). After multivariable adjustment, we still found a negative correlation between serum retinol and BMD, both at the lumbar spine (R = - 0.210; P < 0.01) and at the femoral neck (R = - 0.324, P < 0.001). It is concluded that elevated serum-retinol levels are associated with an increased risk of low bone mass and thus with osteoporotic fractures. Therefore, osteoporosis-risk assessment should include quantification of serum metabolite of vitamin A.

Effects of teriparatide and risedronate on new fractures in post-menopausal women with severe osteoporosis (VERO): a multicentre, double-blind, double-dummy, randomised controlled trial.

BACKGROUND: No clinical trials have compared osteoporosis drugs with incident fractures as the primary outcome. We compared the anti-fracture efficacy of teriparatide with risedronate in patients with severe osteoporosis. METHODS: In this double-blind, double-dummy trial, we enrolled post-menopausal women with at least two moderate or one severe vertebral fracture and a bone mineral density T score of less than or equal to -1·50. Participants were randomly assigned to receive 20 µg of teriparatide once daily plus oral weekly placebo or 35 mg of oral risedronate once weekly plus daily injections of placebo for 24 months. The primary outcome was new radiographic vertebral fractures. Secondary, gated outcomes included new and worsened radiographic vertebral fractures, clinical fractures (a composite of non-vertebral and symptomatic vertebral), and non-vertebral fractures. This study is registered with ClinicalTrials.gov (NCT01709110) and EudraCT (2012-000123-41). FINDINGS: We enrolled 680 patients in each group. At 24 months, new vertebral fractures occurred in 28 (5·4%) of 680 patients in the teriparatide group and 64 (12·0%) of 680 patients in the risedronate group (risk ratio 0·44, 95% CI 0·29-0·68; p<0·0001). Clinical fractures occurred in 30 (4·8%) of 680 patients in the teriparatide group compared with 61 (9·8%) of 680 in the risedronate group (hazard ratio 0·48, 95% CI 0·32-0·74; p=0·0009). Non-vertebral fragility fractures occurred in 25 (4·0%) patients in the teriparatide group and 38 (6·1%) in the risedronate group (hazard ratio 0·66; 95% CI 0·39-1·10; p=0·10). INTERPRETATION: Among post-menopausal women with severe osteoporosis, the risk of new vertebral and clinical fractures is significantly lower in patients receiving teriparatide than in those receiving risedronate. FUNDING: Lilly.

¿Realmente es tan prevalente la deficiencia de vitamina D en España? Situación actual, causas y población de riesgo / No disponible

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Effect of Teriparatide or Risedronate in Elderly Patients With a Recent Pertrochanteric Hip Fracture: Final Results of a 78-Week Randomized Clinical Trial.

We present final results of a study comparing teriparatide 20 µg every day (QD) with risedronate 35 mg once per week (QW) started within 2 weeks after surgery for a pertrochanteric hip fracture. Patients with BMD T-score ≤ -2.0 and 25OHD ≥9.2 ng/mL were randomized to receive 26-week double-dummy treatment plus calcium and vitamin D, followed by 52-week open-label treatment with the same assigned active drug. Primary endpoint was change from baseline in lumbar spine (LS) BMD at 78 weeks. Secondary and exploratory endpoints were change in BMD at the proximal femur, function, hip pain (Charnley score and 100 mm Visual Analog Scale [VAS]), quality of life (Short Form-36), radiology outcomes, and safety. Data were analyzed with mixed models for repeated measures (MMRM) and logistic regression. Totally, 224 patients were randomized; 171 (teriparatide: 86) contributed to the efficacy analyses (mean ± SD age: 77 ± 7.7 years, 77% females). Mean baseline LS, femoral neck (FN), and total hip (TH) T-scores were -2.16, -2.63, and -2.51, respectively. At 78 weeks, BMD increased significantly more with teriparatide compared to risedronate at the LS (+11.08% versus +6.45%; p < 0.001) and FN (+1.96% versus -1.19%; p = 0.003), with no significant between-group difference in TH BMD. Timed up-and-go (TUG) test was significantly faster with teriparatide at 6, 12, 18, and 26 weeks (differences: -3.2 to -5.9 s; p = 0.045 for overall difference). Hip pain during TUG test by 100 mm VAS was significantly lower with teriparatide at 18 weeks (adjusted difference: -11.3 mm, p = 0.033; -10.0 and -9.3 mm at 12 and 26 weeks, respectively; p = 0.079 for overall difference). Other secondary and exploratory outcomes were not different. Teriparatide group showed two new hip fractures versus seven with risedronate (p = 0.171) and more frequent hypercalcemia and hyperuricemia. In conclusion, 78-week treatment with teriparatide showed significantly greater increases in LS and FN BMD, less pain, and a faster TUG test versus risedronate. © 2016 American Society for Bone and Mineral Research.

Low calcium intake and inadequate vitamin D status in postmenopausal osteoporotic women.

UNLABELLED: An observational cross-sectional study was conducted to assess calcium intake and vitamin D status by measurement of 25-hydroxyvitamin D (25(OH)D), in postmenopausal osteoporotic women (PMOW) treated and untreated for osteoporosis. To assess the influence of sunlight exposure on vitamin D status, the study group was categorized on the basis of sunlight exposure (above or below 2500 sunlight h/year). A group of 336 PMOW older than 65 years was identified (190 [56.5%] treated and 146 [43.5%] untreated for osteoporosis). The demographic and clinical data of the PMO women included history of prior fractures, pharmacological treatments and dietary calcium intake. BMD was measured by DEXA and 25(OH)D was determined by an HPLC method. RESULTS: vitamin D serum levels were lower in the untreated group as compared with the treated group (58±27 vs. 67±27nmol/l; p=0.006). Prevalence of vitamin D deficiency (cut-off point set at <50nmol/l) was higher in the non-treated group (43.8% vs. 29.5%; p=0.009). Nearly all PMOW, whether treated or not for osteoporosis had a total calcium intake of less than 1200mg. Sunlight exposure did not influence the vitamin D status. CONCLUSIONS: vitamin D deficiency and an insufficient calcium intake are highly prevalent in both treated and untreated Spanish PMOW older than 65 years. This can be related to low therapeutic adherence and/or insufficient prescription. Therefore physician's and patient's knowledge regarding the optimization of vitamin D status and calcium intake should be improved and implemented. This article is part of a Special Issue entitled 'Vitamin D workshop'.