Review of the safety and efficacy of risedronate for the treatment of male osteoporosis

Osteoporosis in men is an increasingly recognized problem with associated fracture morbidity and mortality. Treatment is limited, with the bisphosphonates being the mainstay of therapy. Risedronate has demonstrated fracture efficacy in women and efficacy has been recently been investigated in men. In men, risedronate either maintains or increases bone mineral density. In placebo controlled trials it has been shown to be safe and effective in preventing fractures

The association between compliance and persistence with bisphosphonate therapy and fracture risk: A review

BACKGROUND: Sub optimal levels of compliance and persistence with bisphosphonates are potentially compromising the reduction of post menopausal osteoporotic (PMO) fracture risk. METHODS: A structured literature search (1990–2006) was performed to identify primary research studies evaluating the relationship between compliance and persistence with bisphosphonates and post menopausal osteoporotic (PMO) fracture risk in clinical practice. Search criteria were: bisphosphonates; osteoporosis/osteopenia in postmenopausal women; all types of fractures; compliance and persistence. RESULTS: Only two retrospective studies using prescription databases have specifically evaluated bisphosphonates. A cohort study tracking 35,537 women reported that in those with a Medication Possession Ratio (MPR) of ≥80% over 24 months the risk of fracture was lower than in those with an MPR of <80% (8.5% v 10.7%, p < 0.001, Relative Risk Reduction (RRR) 21%). In women who persisted with treatment (refill gap <30 days) the risk of fracture was also lower (7.7% v 10.3%, p < 0.001, RRR 29%). A nested case control study reported that 12 months persistence (refill gap <50% previous prescription (Rx) length) was associated with a 26% reduced risk of fracture (p < 0.05) and 24 months with a 32% reduced risk (p < 0.05). Four other studies, not specific to bisphosphonates, reported that compliance ≥12 months decreased fracture risk by ~25%. CONCLUSION: Sub optimal compliance and persistence with bisphosphonates is not providing the best possible protection against the risk of PMO fracture, however, more research is needed to delineate this relationship in clinical practice

If you don’t take it – it can’t work: the consequences of not being treated or nonadherence to osteoporosis therapy

Osteoporosis is a growing problem worldwide, linked to an increasingly aging population. Despite the availability of a wide variety of treatments for osteoporosis, a significant number of patients are either not being prescribed treatment or discontinue therapy as early as 6 months after initiation. The reasons for a lack of adherence are many but poor adherence increases the risk of fracture and, therefore, the disease burden to the patient and society. Results from large-scale, randomized clinical studies have shown that different osteoporosis treatments are efficacious in reducing the risk of fracture. Studies assessing the effects of discontinuing osteoporosis therapies show that some treatments appear to continue to protect patients from the risk of future fracture even when treatment is stopped. However, these trials involve patients who have been compliant with treatment for between 2 and 5 years, a situation not reflective of real-world clinical practice. In reality, patients who discontinue therapy within the first 6 months may never achieve the optimum protection from fracture regardless of which treatment they have been prescribed. Clinicians need to develop management strategies to enable patients to adhere to their treatment. This will ultimately result in better prevention of fracture and a lower burden of disease to society and patients

Development and validation of a new tool to measure the facilitators, barriers and preferences to exercise in people with osteoporosis

Abstract Background Despite the widely known benefits of exercise and physical activity, adherence rates to these activities are poor. Understanding exercise facilitators, barriers, and preferences may provide an opportunity to personalize exercise prescription and improve adherence. The purpose of this study was to develop the Personalized Exercise Questionnaire (PEQ) to identify these facilitators, barriers, and preferences to exercise in people with osteoporosis. Methods This study comprises two phases, instrument design and judgmental evidence. A panel of 42 experts was used to validate the instrument through quantitative (content validity) and qualitative (cognitive interviewing) methods. Content Validity Index (CVI) is the most commonly used method to calculate content validity quantitatively. There are two kinds of CVI: Item-CVI (I-CVI) and Scale-level CVI (S-CVI). Results Preliminary versions of this tool showed high content validity of individual items (I-CVI range: 0.50 to 1.00) and moderate to high overall content validity of the PEQ (S-CVI/UA = 0.63; S-CVI/Ave = 0.91). Through qualitative methods, items were improved until saturation was achieved. The tool consists of 6 domains and 38 questions. The 6 domains are: 1) support network; 2) access; 3) goals; 4) preferences; 5) feedback and tracking; and 6) barriers. There are 35 categorical questions and 3 open-ended items. Conclusions Using an iterative approach, the development and evaluation of the PEQ demonstrated high item-content validity for assessing the facilitators, barriers, and preferences to exercise in people with osteoporosis. Upon further validation it is expected that this measure might be used to develop more client-centered exercise programs, and potentially improve adherence

The Mechanism behind Erosive Bursts in Porous Media

Erosion and deposition during flow through porous media can lead to large erosive bursts that manifest as jumps in permeability and pressure loss. Here we reveal that the cause of these bursts is the re-opening of clogged pores when the pressure difference between two opposite sites of the pore surpasses a certain threshold. We perform numerical simulations of flow through porous media and compare our predictions to experimental results, recovering with excellent agreement shape and power-law distribution of pressure loss jumps, and the behavior of the permeability jumps as function of particle concentration. Furthermore, we find that erosive bursts only occur for pressure gradient thresholds within the range of two critical values, independent on how the flow is driven. Our findings provide a better understanding of sudden sand production in oil wells and breakthrough in filtration.Comment: 7 pages, 8 figure

Ultra long range plasmonic waveguides using quasi two dimensional metallic layers

We calculate the bound plasmonic modes of a quantum metamaterial slab, comprised of multiple quasi two dimensional electron gas (Q2DEG) layers, whose thickness is much smaller than the optical wavelength. For the first order transverse magnetic (TM) optical and the surface plasmonic modes we find propagation constants which are independent of both the electron density and of the scattering rates in the Q2DEGs. This leads to extremely long propagation distances. In a detailed case study of a structure comprising a slab of GaAs/AlGaAs multiple quantum well (MQW) material, we find propagation lengths of 100s of mm. In addition, the electric field enhancement associated with the plasmonic resonance is found to be sufficient to induce the condition of strong coupling between the slab modes and the intersubband transitions in the MQWs

Determining known-group validity and test-retest reliability in the PEQ (personalized exercise questionnaire)

© 2019 The Author(s). Background: To determine the known-group validity, a type of construct validity, and the test-retest reliability of a newly developed tool, the Personalized Exercise Questionnaire (PEQ), that assesses the barriers, facilitators, and preferences to exercise in individuals with low bone mass and osteoporosis. Methods: A comparative design was used to assess known-group validity and a test-retest design to examine the reproducibility. Ninety-five participants with low bone mass and osteoporosis were recruited from an outpatient clinic in Hamilton, Ontario. The questionnaire was administered to 95 participants at baseline and a subset of 42 participants completed the survey again one week later. The known-group validity of the PEQ was determined using four hypotheses that compared two known groups based on employment level, age, socioeconomic status, and physical activity level. The reproducibility of individual responses was analyzed using the Kappa Coefficient (κ). Results: There was known-group validity for three of the four hypotheses. Test-retest reliability scores ranged from no agreement to almost perfect agreement; seven items had almost perfect agreement (κ: 0.81-1.00), 12 substantial agreement (κ: 0.68-0.74), six moderate agreement (κ: 0.56-0.60), two fair agreement (κ: 0.36-0.40), one slight agreement (κ = 0.23) and one no agreement (κ = - 0.03). Conclusion: Preliminary support for the usefulness of the PEQ is indicated since the majority of the items had at least substantial agreement and known-group validity was moderately supported for some items. Trial registration: This study was retrospectively registered with ClinicalTrials.gov, NCT03125590, on April 24, 2017

Frailty index of deficit accumulation and falls: data from the Global Longitudinal Study of Osteoporosis in Women (GLOW) Hamilton cohort

BACKGROUND: To investigate the association between frailty index (FI) of deficit accumulation and risk of falls, fractures, death and overnight hospitalizations in women aged 55 years and older. METHODS: The data were from the Global Longitudinal Study of Osteoporosis in Women (GLOW) Hamilton Cohort. In this 3-year longitudinal, observational cohort study, women (N=3,985) aged ≥ 55 years were enrolled between May 2008 and March 2009 in Hamilton, Canada. A FI including co-morbidities, activities of daily living, symptoms and signs, and healthcare utilization was constructed using 34 health deficits at baseline. Relationship between the FI and falls, fractures, death and overnight hospitalizations was examined. RESULTS: The FI was significantly associated with age, with a mean rate of deficit accumulation across baseline age of 0.004 or 0.021 (on a log scale) per year. During the third year of follow-up, 1,068 (31.89%) women reported at least one fall. Each increment of 0.01 on the FI was associated with a significantly increased risk of falls during the third year of follow-up (odds ratio [OR]: 1.02, 95% confidence interval [CI]: 1.02-1.03). The area under the curve (AUC) of the predictive model was 0.69 (95% CI: 0.67-0.71). Results of subgroup and sensitivity analyses indicated the relationship between the FI and risk of falls was robust, while bootstrap analysis judged its internal validation. The FI was significantly related to fractures (hazard ratio [HR]: 1.02, 95% CI: 1.01-1.03), death (OR: 1.05, 95% CI: 1.03-1.06) during the 3-year follow-up period and overnight hospitalizations (incidence rate ratio [IRR]: 1.02, 95% CI: 1.02-1.03) for an increase of 0.01 on the FI during the third year of follow-up. Measured by per standard deviation (SD) increment of the FI, the ORs were 1.21 and 1.40 for falls and death respectively, while the HR was 1.17 for fractures and the IRR was 1.18 for overnight hospitalizations respectively. CONCLUSION: The FI of deficit accumulation increased with chronological age significantly. The FI was associated with and predicted increased risk of falls, fractures, death and overnight hospitalizations significantly

Osteoporosis in Canadian adult cystic fibrosis patients: A descriptive study

BACKGROUND: Cystic fibrosis is the most common fatal autosomal recessive genetic disease in the Caucasian population. Osteoporosis is increasingly being recognised as an important complication in people with cystic fibrosis. METHODS: A descriptive study of adult cystic fibrosis patients receiving care at a Canadian tertiary care hospital was conducted to evaluate the prevalence of osteoporosis, the prevalence of non-vertebral fractures, and the change in bone mineral density during the course of a year. Data on bone mineral density were obtained for 40 adult cystic fibrosis patients by reviewing dual x-ray absorptiometry scans taken at baseline (when annual scans became standard clinical practice) and one year prior to baseline. Data on prevalent fractures were obtained by reviewing all available patient charts. Clinical and laboratory data were collected from an existing clinic database. RESULTS: Over half of the 40 patients had reduced T- and Z-scores at baseline. For the 27 patients who had data available one year prior to baseline, total hip and lumbar spine bone mineral density had decreased by 3.04% and 0.86% after one year while total body bone mineral density had not changed significantly. Four prior non-vertebral fractures were reported in three patients (1,146 patient-years). CONCLUSION: This study confirms that osteoporosis is a significant problem in adult cystic fibrosis patients, and constitutes the first published evidence of cystic fibrosis bone disease in Canadians