Variation in bone mineral density and fractures over 20 years among Canadians: a comparison of the Canadian Multicenter Osteoporosis Study and the Canadian Longitudinal Study on Aging.

International variations in osteoporosis and fracture rates have been reported, with temporal trends differing between populations. We observed higher BMD and lower fracture prevalence in a recently recruited cohort compared to that of a cohort recruited 20 years ago, even after adjusting for multiple covariates. PURPOSE: We explored sex-specific differences in femoral neck bone mineral density (FN-BMD) and in prevalent major osteoporotic fractures (MOF) using two Canadian cohorts recruited 20 years apart. METHODS: We included men and women aged 50-85 years from the Canadian Multicentre Osteoporosis Study (CaMos, N = 6,479; 1995-1997) and the Canadian Longitudinal Study on Aging (CLSA, N = 19,534; 2012-2015). We created regression models to compare FN-BMD and fracture risk between cohorts, adjusting for important covariates. Among participants with prevalent MOF, we compared anti-osteoporosis medication use. RESULTS: Mean (SD) age in CaMos (65.4 years [8.6]) was higher than in CLSA (63.8 years [9.1]). CaMos participants had lower mean body mass index and higher prevalence of smoking (p < 0.001). Adjusted linear regression models (estimates [95%CI]) demonstrated lower FN-BMD in CaMos women (- 0.017 g/cm2 [- 0.021; - 0.014]) and men (- 0.006 g/cm2 [- 0.011; 0.000]), while adjusted odds ratios (95%CI) for prevalent MOF were higher in CaMos women (1.99 [1.71; 2.30]) and men (2.33 [1.82; 3.00]) compared to CLSA. In women with prevalent MOF, menopausal hormone therapy use was similar in both cohorts (43.3% vs 37.9%, p = 0.076), but supplements (32.0% vs 48.3%, p < 0.001) and bisphosphonate use (5.8% vs 17.3%, p < 0.001) were lower in CaMos. The proportion of men with MOF who received bisphosphonates was below 10% in both cohorts. CONCLUSION: Higher BMD and lower fracture prevalence were noted in the more recently recruited CLSA cohort compared to CaMos, even after adjusting for multiple covariates. We noted an increase in bisphosphonate use in the recent cohort, but it remained very low in men.

Implementing and Evaluating the Impact of BoneRx: A Healthy Bone Prescription for Men with Prostate Cancer Initiating Androgen Deprivation Therapy.

Background: The initiation of Androgen Deprivation Therapy (ADT) results in rapid and profound hypogonadism, resulting in significant bone and muscle loss, increasing the risk for osteoporosis (OP), falls, and fractures. Despite this, there exist very low rates of guideline adherent care regarding bone health in this population. We developed and implemented a healthy bone prescription tool entitled BoneRx to facilitate the uptake of guideline-concordant bone health care into practice and increase patient awareness and promote the uptake of health bone behaviours (HBBs). Methods: We conducted a cross-sectional pre-BoneRx implementation (n = 143) vs. post-implementation (n = 149) cohort study to evaluate the impact on (i) bone health care, patient engagement in HBB, and patient knowledge and health beliefs regarding OP. Results: There was a significant difference pre- vs. post BoneRx implementation on receipt of baseline BMD (34.7% vs. 59.5%, p < 0.0001) and bone health counselling (32.4% vs. 59.9%, p < 0.0001). More participants in the post-BoneRx implementation cohort reported taking vitamin D supplements 57% vs. 81% (p < 0.001) and calcium supplements 39% vs. 61% (p < 0.001). Physical activity levels also significantly increased (p = 0.021). No differences were detected in OP knowledge or feelings of OP susceptibility, seriousness, or health motivation. Conclusion: BoneRx is a simple, cost-effective, and acceptable strategy that could improve the care of PCa survivors receiving ADT.

Hip load capacity cut-points for Astronaut Skeletal Health NASA Finite Element Strength Task Group Recommendations.

Concerns raised at a 2010 Bone Summit held for National Aeronautics and Space Administration Johnson Space Center led experts in finite element (FE) modeling for hip fracture prediction to propose including hip load capacity in the standards for astronaut skeletal health. The current standards for bone are based upon areal bone mineral density (aBMD) measurements by dual X-ray absorptiometry (DXA) and an adaptation of aBMD cut-points for fragility fractures. Task Group members recommended (i) a minimum permissible outcome limit (POL) for post-mission hip bone load capacity, (ii) use of FE hip load capacity to further screen applicants to astronaut corps, (iii) a minimum pre-flight standard for a second long-duration mission, and (iv) a method for assessing which post-mission physical activities might increase an astronaut's risk for fracture after return. QCT-FE models of eight astronaut were analyzed using nonlinear single-limb stance (NLS) and posterolateral fall (NLF) loading configurations. QCT data from the Age Gene/Environment Susceptibility (AGES) Reykjavik cohort and the Rochester Epidemiology Project were analyzed using identical modeling procedures. The 75th percentile of NLS hip load capacity for fractured elderly males of the AGES cohort (9537N) was selected as a post-mission POL. The NLF model, in combination with a Probabilistic Risk Assessment tool, was used to assess the likelihood of exceeding the hip load capacity during post-flight activities. There was no recommendation to replace the current DXA-based standards. However, FE estimation of hip load capacity appeared more meaningful for younger, physically active astronauts and was recommended to supplement aBMD cut-points.

Vitamin K and musculoskeletal health in postmenopausal women.

Aside from its important role in blood clotting, vitamin K is an important dietary factor in regulating bone and cartilage mineralization. The vitamin K requirements to maintain musculoskeletal health may be more than the current recommendations and subclinical vitamin K deficiency may be involved in the pathogenesis of osteoporosis and osteoarthritis. Observational studies suggest that diets low in vitamin K are associated with increased risk of fractures and osteoarthritis in older adults. However, so far randomized controlled trials of vitamin K supplementation in Caucasian populations have not shown clinically significant improvements in bone mineral density at major skeletal sites. Supplementation with vitamin K may reduce the risk of fractures, but this conclusion comes from clinical trials with methodological limitations. At this time, only one randomized controlled trial has examined the effect of vitamin K supplementation on radiographic hand osteoarthritis and found no overall effect. Large well-designed randomized controlled trials are needed to compare the efficacies of vitamin K1 and K2 on fractures and osteoarthritis among older adults. In summary, currently there is not enough evidence to recommend the use of vitamin K supplements for the prevention of bone loss, fractures, or osteoarthritis in postmenopausal women.

Effects of adjuvant exemestane versus anastrozole on bone mineral density for women with early breast cancer (MA.27B): a companion analysis of a randomised controlled trial.

BACKGROUND: Treatment of breast cancer with aromatase inhibitors is associated with damage to bones. NCIC CTG MA.27 was an open-label, phase 3, randomised controlled trial in which women with breast cancer were assigned to one of two adjuvant oral aromatase inhibitors-exemestane or anastrozole. We postulated that exemestane-a mildly androgenic steroid-might have a less detrimental effect on bone than non-steroidal anastrozole. In this companion study to MA.27, we compared changes in bone mineral density (BMD) in the lumbar spine and total hip between patients treated with exemestane and patients treated with anastrozole. METHODS: In MA.27, postmenopausal women with early stage hormone (oestrogen) receptor-positive invasive breast cancer were randomly assigned to exemestane 25 mg versus anastrozole 1 mg, daily. MA.27B recruited two groups of women from MA.27: those with BMD T-scores of -2·0 or more (up to 2 SDs below sex-matched, young adult mean) and those with at least one T-score (hip or spine) less than -2·0. Both groups received vitamin D and calcium; those with baseline T-scores of less than -2·0 also received bisphosphonates. The primary endpoints were percent change of BMD at 2 years in lumbar spine and total hip for both groups. We analysed patients according to which aromatase inhibitor and T-score groups they were allocated to but BMD assessments ceased if patients deviated from protocol. This study is registered with ClinicalTrials.gov, NCT00354302. FINDINGS: Between April 24, 2006, and May 30, 2008, 300 patients with baseline T-scores of -2·0 or more were accrued (147 allocated exemestane, 153 anastrozole); and 197 patients with baseline T-scores of less than -2·0 (101 exemestane, 96 anastrozole). For patients with T-scores greater than -2·0 at baseline, mean change of bone mineral density in the spine at 2 years did not differ significantly between patients taking exemestane and patients taking anastrozole (-0·92%, 95% CI -2·35 to 0·50 vs -2·39%, 95% CI -3·77 to -1·01; p=0·08). Respective mean loss in the hip was -1·93% (95% CI -2·93 to -0·93) versus -2·71% (95% CI -4·32 to -1·11; p=0·10). Likewise for those who started with T-scores of less than -2·0, mean change of spine bone mineral density at 2 years did not differ significantly between the exemestane and anastrozole treatment groups (2·11%, 95% CI -0·84 to 5·06 vs 3·72%, 95% CI 1·54 to 5·89; p=0·26), nor did hip bone mineral density (2·09%, 95% CI -1·45 to 5·63 vs 0·0%, 95% CI -3·67 to 3·66; p=0·28). Patients with baseline T-score of -2·0 or more taking exemestane had two fragility fractures and two other fractures, those taking anastrozole had three fragility fractures and five other fractures. For patients who had baseline T-scores of less than -2·0 taking exemestane, one had a fragility fracture and four had other fractures, whereas those taking anastrozole had five fragility fractures and one other fracture. INTERPRETATION: Our results demonstrate that adjuvant treatment with aromatase inhibitors can be considered for breast cancer patients who have T-scores less than -2·0. FUNDING: Canadian Cancer Society Research Institute, Pfizer, Canadian Institutes of Health Research.

Vitamin K and bone health.

Vitamin K has been purported to play an important role in bone health. It is required for the gamma-carboxylation of osteocalcin (the most abundant noncollagenous protein in bone), making osteocalcin functional. There are 2 main forms (vitamin K1 and vitamin K2), and they come from different sources and have different biological activities. Epidemiologic studies suggest a diet high in vitamin K is associated with a lower risk of hip fractures in aging men and women. However, randomized controlled trials of vitamin K1 or K2 supplementation in white populations did not increase bone mineral density at major skeletal sites. Supplementation with vitamin K1 and K2 may reduce the risk of fractures, but the trials that examined fractures as an outcome have methodological limitations. Large well-designed trials are needed to compare the efficacies of vitamin K1 and K2 on fractures. We conclude that currently there is not enough evidence to recommend the routine use of vitamin K supplements for the prevention of osteoporosis and fractures in postmenopausal women.

Breast cancer and osteoporosis.

PURPOSE OF REVIEW: Over the past few years, a number of studies have examined the relationship between breast cancer and osteoporosis, the effect of breast cancer treatment on bone health, and the effect of osteoporosis therapies on aromatase inhibitor-induced bone loss and breast cancer recurrence. New guidelines have been released on the prevention of osteoporotic fractures in women with breast cancer who are on aromatase inhibitors for adjuvant therapy. RECENT FINDINGS: Despite common factors linking high bone mineral density and increased risk of breast cancer, women with breast cancer are not protected from osteoporosis or osteoporotic fractures. Recent data suggest that aromatase inhibitors have a detrimental effect on bone mineral density and can increase the risk of fractures. Bisphosphonate therapy not only preserves aromatase inhibitor-induced bone loss, but may also improve disease-free survival and decrease risk of death in select women with breast cancer (i.e., postmenopausal women). SUMMARY: Osteoporosis and breast cancer are common in women, especially in postmenopausal women. Current guidelines suggest that we need to pay special attention to those on aromatase inhibitors to prevent adverse bone outcomes.

Effects of vitamin E on bone turnover markers among US postmenopausal women.

Increased oxidative stress and inflammation resulting from aging and declining estrogen levels can lead to increased bone loss in postmenopausal women. Alpha-tocopherol and gamma-tocopherol, the two predominant isomers of vitamin E, have antioxidant and anti-inflammatory properties, but their effects on bone metabolism have not been well studied in humans. We examined the associations between dietary and total (diet and supplements) alpha-tocopherol intake, serum alpha-tocopherol and gamma-tocopherol levels and their ratio, and bone turnover markers (BTMs) among postmenopausal women aged ≥45 years. We used cross-sectional data from the National Health and Nutrition Examination Survey 1999­2002. Multiple regression models with adjustments for relevant confounders were used to examine the associations between intake and serum levels of tocopherols, and serum bone-specific alkaline phosphatase (BAP), a biomarker of bone formation, and urinary N-telopeptides/creatinine (uNTx/Cr), a biomarker of bone resorption. The study sample included 497 postmenopausal women who were not taking estrogen, steroids, or osteoporosis medications, were free from kidney and liver disease, cancer, and rheumatoid arthritis, and were fasting >9 hours prior to examination. Participants had a mean age of 65.5 ± 0.6 years and over 45% used vitamin E (alpha-tocopherol) supplements in the past month. Vitamin E supplement users had significantly lower serum gamma-tocopherol, higher serum alpha-tocopherol levels, and higher ratio of serum alpha-tocopherol to gamma-tocopherol than nonusers. High serum gamma-tocopherol levels and low ratio of serum alpha-tocopherol to gamma-tocopherol were associated with increased BAP levels (p < 0.01 for both). There were no associations between any of the vitamin E variables and uNTx/Cr. In conclusion, we hypothesize that gamma-tocopherol may uncouple bone turnover, resulting in more bone formation than resorption. Vitamin E supplements in the form of alpha-tocopherol suppress serum gamma-tocopherol levels and may have negative effects on bone formation. Further research is needed to investigate the potential anabolic effect of gamma-tocopherol from food sources on bone.

Bone density and structure in healthy postmenopausal women treated with exemestane for the primary prevention of breast cancer: a nested substudy of the MAP.3 randomised controlled trial.

BACKGROUND: Exemestane can prevent breast cancer in postmenopausal women. Because of potential widespread use, we examined the safety of exemestane on bone health. METHODS: In this nested safety substudy of the MAP.3 trial (a randomised, placebo-controlled, double-blind trial of exemestane 25 mg a day for the primary prevention of breast cancer), we included postmenopausal women from five centres who were eligible to participate in MAP.3, not osteoporotic, not receiving drugs for bone-related disorders, with baseline lumbar spine, total hip, and femoral neck T-scores above -2·0. The primary endpoint was percent change from baseline to 2 years in total volumetric bone mineral density (BMD) at the distal radius by high-resolution peripheral quantitative CT. The primary analysis was per protocol using a non-inferiority margin. This analysis was done earlier than originally planned because of the impending announcement of MAP.3 results and subsequent unmasking of patients to treatment assignment. This study is registered with ClinicalTrials.gov, number NCT01144468, and has been extended to 5 years of unmasked follow-up. FINDINGS: 351 women (176 given exemestane, 175 given placebo; median age 61·3 years [IQR 59·2-64·9]) met our inclusion criteria and completed baseline assessment. At the time of clinical cutoff, 242 women had completed 2-year follow-up (124 given exemestane, 118 given placebo). From baseline to 2 years, the mean percent change in total volumetric BMD at the distal radius was -6·1% (95% CI -7·0 to -5·2) in the exemestane group and -1·8% (-2·4 to -1·2) in the placebo group (difference -4·3%, 95% CI -5·3 to -3·2; p<0·0001). The lower limit of the 95% CI was lower than our non-inferiority margin of negative 4% (one-sided test for non-inferiority p=0·70), meaning the hypothesis that exemestane was inferior could not be rejected. At the distal tibia, the mean percent change in total volumetric BMD from baseline to 2 years was -5·0% (95% CI -5·5 to -4·4) in the exemestane group and -1·3% (-1·7 to -1·0) in the placebo group (difference -3·7%, 95% CI -4·3 to -3·0; p<0·0001). The mean percent change in cortical thickness was -7·9% (SD 7·3) in the exemestane group and -1·1% (5·7) in the placebo group at the distal radius (difference -6·8%, 95% CI -8·5 to -5·0; p<0·0001) and -7·6% (SD 5·9) in the exemestane group and -0·7% (4·9) in the placebo group at the distal tibia (difference -6·9%, -8·4 to -5·5; p<0·0001). Decline in areal BMD, as measured by dual-energy x-ray absorptiometry, in the exemestane group compared with the placebo group occurred at the lumbar spine (-2·4% [95% CI -3·1 to -1·7] exemestane vs -0·5% [-1·1 to 0·2] placebo; difference -1·9%, 95% CI -2·9 to -1·0; p<0·0001), total hip (-1·8% [-2·3 to -1·2] exemestane vs -0·6% [-1·1 to -0·1] placebo; difference -1·2%, -1·9 to -0·4; p=0·004), and femoral neck (-2·4% [-3·2 to -1·7] exemestane vs -0·8% [-1·5 to 0·1] placebo; difference -1·6%, -2·7 to -0·6; p=0·002). INTERPRETATION: 2 years of treatment with exemestane worsens age-related bone loss in postmenopausal women despite calcium and vitamin D supplementation. Women considering exemestane for the primary prevention of breast cancer should weigh their individual risks and benefits. For women taking exemestane, regular bone monitoring plus adequate calcium and vitamin D supplementation are important. To assess the effect of our findings on fracture risk, long-term follow-up is needed. FUNDING: Canadian Breast Cancer Research Alliance (Canadian Institutes of Health Research/Canadian Cancer Society).

Effect of 12 months of whole-body vibration therapy on bone density and structure in postmenopausal women: a randomized trial.

BACKGROUND: Although data from studies in animals demonstrated beneficial effects of whole-body vibration (WBV) therapy on bone, clinical trials in postmenopausal women showed conflicting results. OBJECTIVE: To determine whether WBV improves bone density and structure. DESIGN: A 12-month, single-center, superiority, randomized, controlled trial with 3 parallel groups. (ClinicalTrials.gov registration number: NCT00420940) SETTING: Toronto General Hospital, Ontario, Canada. PARTICIPANTS: 202 healthy postmenopausal women with bone mineral density (BMD) T-scores between -1.0 and -2.5 who were not receiving prescription bone medications. INTERVENTION: Participants were randomly assigned to 1 of 3 groups (1:1:1 ratio) by using a block-randomization scheme and sealed envelopes. They were asked to stand on a low-magnitude (0.3g) 90-Hz or 30-Hz WBV platform for 20 minutes daily or to serve as control participants; all participants received calcium and vitamin D. MEASUREMENTS: Bone outcome assessors, who were blinded to group assignment, determined trabecular volumetric BMD and other measurements of the distal tibia and distal radius with high-resolution peripheral quantitative computed tomography and areal BMD with dual-energy x-ray absorptiometry at baseline and at 12 months. RESULTS: 12 months of WBV therapy had no significant effect on any bone outcomes compared with no WBV therapy. For the primary outcome of tibial trabecular volumetric BMD, mean change from baseline was 0.4 mg/cm(3) (95% CI, -0.4 to 1.2 mg/cm(3)) in the 90-Hz WBV group, -0.1 mg/cm(3) (CI, -1.0 to 0.8 mg/cm(3)) in the 30-Hz WBV group, and -0.2 mg/cm(3) (CI, -1.1 to 0.6 mg/cm(3)) in the control group (P = 0.55). Changes in areal BMD at the femoral neck, total hip, and lumbar spine were also similar among the groups. Overall, low-magnitude WBV at both 90 and 30 Hz was well-tolerated. LIMITATIONS: Adherence to WBV ranged from 65% to 79%. Double-blinding was not possible. CONCLUSION: Whole-body vibration therapy at 0.3g and 90 or 30 Hz for 12 months did not alter BMD or bone structure in postmenopausal women who received calcium and vitamin D supplementation.

Validation of a calcium assessment tool in postmenopausal Canadian women.

UNLABELLED: Adequate calcium intake is important for optimal bone health. Assessing dietary calcium intake, however, is neither widely done nor standardized in North American clinical practices. OBJECTIVE: Our goal was to validate a calcium assessment tool (CAT), a modified version of the Calcium Calculator™, against the 3-day food record. METHODS: Data were obtained from 348 participants in the ECKO (Evaluation of the Clinical use of vitamin K supplementation in postmenopausal women with Osteopenia) trial. In this study, CAT data was collected at baseline and 3-day food records (FRs) were collected at baseline and 3 months by trained study coordinators. CAT and 3-day FR data were compared using correlations and Bland-Altman plots. Additionally, receiver operator characteristic (ROC) curves of CAT were constructed to identify subjects with low calcium intake at thresholds of 500 mg/day and 1000 mg/day on the 3-day FR curves. RESULTS: Mean calcium intake values per day were 902 mg for the 3-day FRs and 781 mg for the CAT. The Pearson correlation was 0.57 (95% CI: 0.50-0.64). Areas under the ROC curves at thresholds of 500 and 1000 mg calcium were 0.81 (95% CI: 0.73-0.89) and 0.82 (95% CI: 0.78-0.86), respectively. CONCLUSIONS: The CAT is a valid tool for the measurement of dietary calcium intake using cut-off values of 500 mg and 1000 mg in postmenopausal women, even though there is only moderate correlation between the CAT and 3-day FR. This tool may facilitate the determination of whether calcium supplements are needed in the clinical setting.

A scoping review of strategies for the prevention of hip fracture in elderly nursing home residents.

BACKGROUND: Elderly nursing home residents are at increased risk of hip fracture; however, the efficacy of fracture prevention strategies in this population is unclear. OBJECTIVE: We performed a scoping review of randomized controlled trials of interventions tested in the long-term care (LTC) setting, examining hip fracture outcomes. METHODS: We searched for citations in 6 respective electronic searches, supplemented by hand searches. Two reviewers independently reviewed all citations and full-text papers; consensus was achieved on final inclusion. Data was abstracted in duplicate. FINDINGS: We reviewed 22,349 abstracts or citations and 949 full-text papers. Data from 20 trials were included: 7--vitamin D (n = 12,875 participants), 2--sunlight exposure (n = 522), 1--alendronate (n = 327), 1--fluoride (n = 460), 4--exercise or multimodal interventions (n = 8,165), and 5--hip protectors (n = 2,594). Vitamin D, particularly vitamin D(3) > or = 800 IU orally daily, reduced hip fracture risk. Hip protectors reduced hip fractures in included studies, although a recent large study not meeting inclusion criteria was negative. Fluoride and sunlight exposure did not significantly reduce hip fractures. Falls were reduced in three studies of exercise or multimodal interventions, with one study suggesting reduced hip fractures in a secondary analysis. A staff education and risk assessment strategy did not significantly reduce falls or hip fractures. In a study underpowered for fracture outcomes, alendronate did not significantly reduce hip fractures in LTC. CONCLUSIONS: The intervention with the strongest evidence for reduction of hip fractures in LTC is Vitamin D supplementation; more research on other interventions is needed.

Vitamin K supplementation in postmenopausal women with osteopenia (ECKO trial): a randomized controlled trial.

BACKGROUND: Vitamin K has been widely promoted as a supplement for decreasing bone loss in postmenopausal women, but the long-term benefits and potential harms are unknown. This study was conducted to determine whether daily high-dose vitamin K1 supplementation safely reduces bone loss, bone turnover, and fractures. METHODS AND FINDINGS: This single-center study was designed as a 2-y randomized, placebo-controlled, double-blind trial, extended for earlier participants for up to an additional 2 y because of interest in long-term safety and fractures. A total of 440 postmenopausal women with osteopenia were randomized to either 5 mg of vitamin K1 or placebo daily. Primary outcomes were changes in BMD at the lumbar spine and total hip at 2 y. Secondary outcomes included changes in BMD at other sites and other time points, bone turnover markers, height, fractures, adverse effects, and health-related quality of life. This study has a power of 90% to detect 3% differences in BMD between the two groups. The women in this study were vitamin D replete, with a mean serum 25-hydroxyvitamin D level of 77 nmol/l at baseline. Over 2 y, BMD decreased by -1.28% and -1.22% (p = 0.84) (difference of -0.06%; 95% confidence interval [CI] -0.67% to 0.54%) at the lumbar spine and -0.69% and -0.88% (p = 0.51) (difference of 0.19%; 95% CI -0.37% to 0.75%) at the total hip in the vitamin K and placebo groups, respectively. There were no significant differences in changes in BMD at any site between the two groups over the 2- to 4-y period. Daily vitamin K1 supplementation increased serum vitamin K1 levels by 10-fold, and decreased the percentage of undercarboxylated osteocalcin and total osteocalcin levels (bone formation marker). However, C-telopeptide levels (bone resorption marker) were not significantly different between the two groups. Fewer women in the vitamin K group had clinical fractures (nine versus 20, p = 0.04) and fewer had cancers (three versus 12, p = 0.02). Vitamin K supplements were well-tolerated over the 4-y period. There were no significant differences in adverse effects or health-related quality of life between the two groups. The study was not powered to examine fractures or cancers, and their numbers were small. CONCLUSIONS: Daily 5 mg of vitamin K1 supplementation for 2 to 4 y does not protect against age-related decline in BMD, but may protect against fractures and cancers in postmenopausal women with osteopenia. More studies are needed to further examine the effect of vitamin K on fractures and cancers. TRIAL REGISTRATION: ClinicalTrials.gov (#NCT00150969) and Current Controlled Trials (#ISRCTN61708241).

Prevention and management of osteoporosis in men receiving androgen deprivation therapy: a survey of urologists and radiation oncologists.

OBJECTIVES: To determine the current practice of clinicians in the diagnosis and management of osteoporosis among men taking androgen deprivation therapy (ADT), because ADT leads to decreased bone mineral density (BMD) and fractures. METHODS: We sent out a survey to Canadian urologists and radiation oncologists. The survey included questions about BMD testing, treatment practices, referral patterns, and risk of osteoporosis. RESULTS: The surveys were returned by 170 of 294 respondents (response rate 58%). Few respondents would obtain a baseline BMD in patients starting ADT. Forty percent would order a repeat BMD test after starting ADT if the baseline BMD were normal or unknown, but more than two thirds would if the baseline BMD showed osteoporosis. In men with a normal BMD starting ADT, respondents recommended weight-bearing exercises (58%), calcium (50%), vitamin D (47%), and bisphosphonate (6%) supplements. In men with osteoporosis at baseline, the use of nonprescription therapies increased slightly and bisphosphonate use increased to 44%. If osteoporosis were diagnosed, 11% would treat the patient themselves. The estimated risk of developing osteoporosis within 1 year of starting ADT with a normal baseline BMD ranged from 0% to 90% (median 20%). CONCLUSIONS: To our knowledge, this is the first survey of its kind. The key findings included that few physicians would order a baseline BMD test, would prescribe bisphosphonates for prevention but almost one half would consider bisphosphonates to treat established osteoporosis, and wide variations exist in the practice patterns and risk perception surrounding ADT-related osteoporosis. Evidence-based guidelines are needed to help physicians deal effectively with osteoporosis prevention and management among men taking ADT.

Isoflavones with supplemental calcium provide greater protection against the loss of bone mass and strength after ovariectomy compared to isoflavones alone.

Although hormone replacement therapy (HRT) and calcium (Ca) supplementation preserve bone mass more when combined, there is a growing concern over the safety of HRT that necessitates thorough investigation of effective, alternative treatments for bone loss. While plant-derived estrogen-like compounds such as isoflavones preserve bone, it is not known whether isoflavones and Ca supplementation attenuate losses in bone mass and strength to a greater extent when combined. This study compared the effects of an isoflavone extract + high Ca to isoflavone extract or high Ca alone on preservation of bone mineral density (BMD) and biomechanical strength in ovariectomized (ovx) rats. Rats were sham-operated (n = 10) or ovx (n = 40). Shams were fed a 0.2% Ca diet. Ovx rats were randomized to a 0.2% Ca diet alone (OVX) or with isoflavone extract (IE; 1.6 g/kg diet) or to a high Ca diet (Ca; 2.5%) alone or a high Ca diet with the isoflavone extract (IE + Ca) for 8 weeks. BMD of femur and lumbar spine were measured by dual-energy X-ray absorptiometry. The biomechanical strength of femurs and individual vertebra was measured by three-point bending and compression testing, respectively. The average food intake was lowest (P < 0.05) among sham and IE groups and greatest (P < 0.05) among the OVX group. Final body weight was lowest (P < 0.05) among shams and highest (P < 0.05) among the OVX group while IE + Ca were lighter (P < 0.05) than all ovx groups. Femur and vertebra BMD was greater (P < 0.05) among IE + Ca and sham rats compared to IE, Ca, or OVX rats. Although there were differences in femur BMD among groups, biomechanical properties at the femur midpoint did not differ among groups, possibly due to the lack of cortical bone loss at this site. Conversely, vertebra biomechanical strength was greater (P < 0.05) among IE + Ca and Ca alone groups compared to IE alone. Uterine weight was higher (P < 0.05) among shams than OVX and IE with no difference among shams, Ca, or IE + Ca rats, suggesting that the isoflavones did not have an uterotrophic effect. In conclusion, isoflavones combined with high Ca are more protective against the loss of femur and vertebra BMD than isoflavones or high Ca diet alone.

Biomechanical bone strength and bone mass in young male and female rats fed a fish oil diet.

The study objective was to determine if male and female rats fed a diet rich in fish oil had femurs and vertebrae that were stronger and more resistant to fracture than rats not fed omega-3 long chain polyunsaturated fatty acids. Weanling rats were randomized to a control or a fish oil diet for 5 weeks. Feeding fish oil to males had no effect on biomechanical strength properties of femurs and vertebrae as measured by three point bending and compression, respectively. In contrast, females fed fish oil had reduced length growth and a lower vertebral peak load. These effects may have been partly mediated by a lower food intake but were not associated with differences in serum IGF-I, estradiol or urinary calcium. The effect of consuming a fish oil diet into later adulthood should be investigated to determine if femur strength is also affected among females.