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Biomedical subjects

Alexandra Papaioannou

Publications and source records attributed to Alexandra Papaioannou.

At least 19 recordsLinked to original sources

Changes to osteoporosis prevalence according to method of risk assessment.

UNLABELLED: The impact of clinical risk factor-based absolute risk methods on the prevalence of high risk for osteoporotic fracture is unknown. We applied absolute risk methods to 6646 subjects and found that the prevalence of elderly women deemed to be at high risk increased substantially, whereas the overall prevalence was highly dependent on the threshold used to designate high risk. INTRODUCTION: Many groups have advocated using absolute risk methods that incorporate clinical risk factors to target patients for osteoporosis therapy. We examined how the application of such absolute risk classification systems influences the prevalence of those considered to be at high risk for osteoporotic fracture and compared these systems to one based solely on BMD. MATERIALS AND METHODS: Using 6646 subjects from the Canadian Multicentre Osteoporosis Study (CaMos), a prospective, randomly selected, population-based cohort, we assessed three different systems for determining prevalence of high risk for osteoporotic fracture: a BMD-based system; a simplified risk factor system incorporating age, sex, BMD, and two clinical risk factors; and a comprehensive system, incorporating age, sex, BMD, and seven clinical risk factors. The 10-year absolute risks of incident fragility fracture were compared across systems using three different high-risk thresholds. RESULTS: The prevalence of a T score < or = -2.5 was 18.8% (95% CI: 17.7-19.9%) in women and 3.9% (95% CI: 3.0-4.7%) in men. Using a 15% 10-year risk of fracture threshold, the prevalence of women at high risk increased to 46.9% (95% CI: 45.4-48.4) and 42.5% (95% CI: 41.1-43.9) when the comprehensive and simplified risk factor classification systems were used, respectively. Using a 25% 10-year absolute risk threshold, the prevalence of high risk was similar to that of the BMD-based system, whereas the 20% threshold gave intermediate rates. All thresholds analyzed resulted in an increased prevalence of older women at high risk for fracture, whereas only the 15% 10-year risk of fracture threshold resulted in an increase in the prevalence of men at high risk. CONCLUSIONS: The application of risk factor-based systems results in an increased prevalence of older women at high risk. The prevalence of individuals at high risk may increase with changes to the methods used to determine those who are eligible for therapy. These data have important implications for the pattern of care and costs of treating osteoporotic fractures.

Absorptiometry, Photon↗

Patient adherence to osteoporosis medications: problems, consequences and management strategies.

Adherence to osteoporosis medications is relatively poor. Approximately 20-30% of patients taking daily or weekly treatments may suspend their treatment within 6 to 12 months of initiating therapy. Patients with poor adherence increase their risk of osteoporotic fractures and hospitalisation. The majority of patients who discontinue therapy appear to do so because of drug-induced adverse effects. Fear of adverse effects or other health risks is another commonly cited reason for discontinuing therapy. Factors associated with medication adherence include fractures, regular exercise, female sex, fewer non-osteoporosis medications and co-morbidities, early menopause, willingness to take medications, awareness of osteoporosis status based on a diagnostic test, anti-inflammatory therapy and corticosteroid therapy. Factors associated with non-adherence include adverse effects, pain and being unsure about bone mineral density (BMD) test results. Bisphosphonates, a common class of drugs for treating osteoporosis, have specific administration requirements (e.g. fasting, remaining upright and not ingesting other medications concomitantly). Patient surveys indicate that 12-18% of patients report non-compliance with at least one administration rule. Strategies to increase adherence include reducing administration frequency to weekly or monthly, monitoring patients with bone markers and BMD testing, providing adequate instructions, practitioner feedback and support, and educational materials and sessions. Future studies are needed regarding strategies to increase adherence to osteoporosis medications.

Aged↗

What is the number of older Canadians needed to screen by measurement of bone density to detect an undiagnosed case of osteoporosis? a population-based study from CaMos.

Routine bone mineral densitometry (BMD) screening has been recommended for women aged >or=65 yr (Osteoporosis Canada [OC], International Society for Clinical Densitometry [ISCD], Canadian and United States Task Forces on Preventative Healthcare, and National Osteoporosis Foundation) and for men >or=65 yr (OC) or >or=70 yr (ISCD). We estimated the number of older Canadians needed to screen (NNS) by BMD to detect an undiagnosed case of osteoporosis, using prospective, multicenter, population-based data from the Canadian Multicentre Osteoporosis Study (CaMos). We included participants aged >or=65 yr with baseline dual-energy X-ray absorptiometry (DXA) BMDs at the femoral neck and lumbar spine (L1-L4). Osteoporosis was defined by a T-score or=65 yr. The percentage prevalence and 95% confidence intervals were determined. In individuals aged >or=65 yr, the prevalence of osteoporosis was 25.6% in women (95% confidence interval, 24.0%, 27.3%) and 8.9% in men (7.3%, 10.8%). In 652 men aged >or=70 yr, the prevalence of osteoporosis was 11.3% (9.1%, 14.0%). Of the participants with BMD-defined osteoporosis, 76.6% of woman aged >or=65 yr (73.2%, 79.6%; 516 of 674 women), 93.4% of men aged >or=65 yr (86.4%, 96.9%; 85 of 91), and 93.2% of men >or=70 yr (84.9%, 97.0%; 68 of 73) were not aware of it. Thus, the minimum NNS by BMD testing to detect one previously undiagnosed case of osteoporosis in Canada is: 6 women aged >or=65 yr, 13 men aged >or=65 yr, and 10 men aged >or=70 yr.

Absorptiometry, Photon↗

Parathyroid hormone for the treatment of osteoporosis: a systematic review.

BACKGROUND: Human parathyroid hormone (hPTH)(1-34) was approved in 2004 for the treatment of severe osteoporosis. Members of the Osteoporosis Canada clinical guidelines committee conducted a systematic review of randomized controlled trials (RCTs) to assess the efficacy and safety of hPTH for fracture prevention in postmenopausal women and men with osteoporosis. METHODS: We searched MEDLINE, EMBASE, HTA, Current Contents and the Cochrane Controlled Trials Registry for published data from 1966 to February 2005. A systematic literature search for RCTs was conducted using the Cochrane Collaborative approach. We identified 12 trials that randomly assigned patients either to hPTH or placebo or to hPTH or an active comparator and were at least 1 year in duration. Outcomes included change in bone mineral density (BMD), fractures, back pain and adverse events. Two independent reviewers abstracted data on study characteristics and outcomes. RESULTS: hPTH(1-34) significantly increases lumbar spine BMD, with smaller increases at the femoral neck and total hip. hPTH(1-84) significantly increases lumbar spine BMD. The data show a significant reduction in both vertebral and nonvertebral fractures with hPTH(1-34) in postmenopausal women with previous vertebral fractures. There were no data on fractures comparing the approved dose of hPTH(1-34) with active comparators. INTERPRETATION: There is Level I evidence that hPTH(1-34) significantly increases BMD at all skeletal sites except the radius and significantly reduces the risk of new vertebral and nonvertebral fractures in postmenopausal women with prior fractures.

Adrenal Cortex Hormones↗

The effects of antifracture therapies on the components of bone strength: assessment of fracture risk today and in the future.

OBJECTIVE: To summarize the current knowledge regarding the impact of the most common antifracture medications on the various determinants of bone strength. METHODS: Relevant English-language articles acquired from Medline from 1966 to January 2005 were reviewed. Searches included the keywords bone AND 1 of the following: strength, remodeling, microcrack, structure, mineralization, collagen, organic, crystallinity, osteocyte, porosity, diameter, anisotropy, stress risers, or connectivity AND alendronate, estrogen, etidronate, hormone replacement therapy, parathyroid hormone, risedronate, OR teriparatide. Abstracts from relevant conference proceedings were also reviewed for pertinent information. RESULTS: Antiresorptive therapies increase bone strength through decreasing bone turnover. This lower bone turnover results in a higher mean mineralization and decreases the number of active resorption pits within bone at any given time. These resorption pits are speculated to be areas of focal weakness and a higher number of them would, if all other things were equal, result in greater fragility. Parathyroid hormone therapy increases the rate of bone remodeling, which introduces many resorption pits, but this source of strength loss is thought to be compensated by rapid increases in bone mass. CONCLUSIONS: Both the antiresorptives, particularly bisphosphonates, and the parathyroid hormone therapy increase bone strength; however, the changes that are elicited to achieve this differ significantly.

Bone Density↗

Bone strength: the whole is greater than the sum of its parts.

OBJECTIVE: To summarize the current knowledge regarding the various determinants of bone strength. METHODS: Relevant English-language articles acquired from Medline from 1966 up to January 2005 were reviewed. Searches included the keywords bone AND 1 of the following: strength, remodeling, microcrack, structur*, mineralization, collagen, organic, crystallinity, osteocyte, porosity, diameter, anisotropy, stress risers, or connectivity. Abstracts from applicable conference proceedings were also reviewed for pertinent information. RESULTS: Bone strength is determined from both its material and its structural properties. Material properties such as its degree of mineralization, crystallinity, collagen characteristics, and osteocyte viability have substantial impacts on bone strength. Structural properties such as the diameter and thickness of the cortices, the porosity of the cortical shell, the connectivity and anisotropy of the trabecular network, the thickness of trabeculae, and the presence of trabecular stress risers and microcracks impact bone strength in diverse manners. Remodeling activity either directly or indirectly impacts all of these processes. CONCLUSIONS: Bone strength is dependent on numerous, interrelated factors. Remodeling activity has a direct impact on almost all of the components of bone strength and requires further investigation as to its impact on these factors in isolation and in unison.

Bone Density↗

Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency: a systematic review of randomized controlled trials.

BACKGROUND: Vitamin B(12) deficiency is common, increasing with age. Most people are treated in primary care with intramuscular vitamin B(12). Several studies have reported equal efficacy of oral administration of vitamin B(12). OBJECTIVES: We set out to identify randomized controlled trial (RCT) evidence for the effectiveness of oral versus intramuscular vitamin B(12) to treat vitamin B(12) deficiency. METHODS: We conducted a systematic review searching databases for relevant RCTs. Outcomes included levels of serum vitamin B(12), total serum homocysteine and methylmalonic acid, haemoglobin and signs and symptoms of vitamin B(12) deficiency. RESULTS: Two RCTs comparing oral with intramuscular administration of vitamin B(12) met our inclusion criteria. The trials recruited a total of 108 participants and followed up 93 of these from 90 days to 4 months. In one of the studies, mean serum vitamin B(12) levels were significantly higher in the oral (643 +/- 328 pg/ml; n = 18) compared with the intramuscular group (306 +/- 118 pg/ml; n = 15) at 2 months (P < 0.001) and 4 months (1005 +/- 595 versus 325 +/- 165 pg/ml; P < 0.0005) and both groups had neurological responses. In the other study, serum vitamin B(12) levels increased significantly in those receiving oral vitamin B(12) and intramuscular vitamin B(12) (P < 0.001). CONCLUSIONS: The evidence derived from these limited studies suggests that 2000 microg doses of oral vitamin B(12) daily and 1000 microg doses initially daily and thereafter weekly and then monthly may be as effective as intramuscular administration in obtaining short-term haematological and neurological responses in vitamin B(12)-deficient patients.

Administration, Oral↗

Canadian Consensus Conference on osteoporosis, 2006 update.

OBJECTIVE: To provide guidelines for the health care provider on the diagnosis and clinical management of postmenopausal osteoporosis. OUTCOMES: Strategies for identifying and evaluating high-risk individuals, the use of bone mineral density (BMD) and bone turnover markers in assessing diagnosis and response to management, and recommendations regarding nutrition, physical activity, and the selection of pharmacologic therapy to prevent and manage osteoporosis. EVIDENCE: MEDLINE and the Cochrane database were searched for articles in English on subjects related to osteoporosis diagnosis, prevention, and management from March 2001 to April 2005. The authors critically reviewed the evidence and developed the recommendations according to the Journal of Obstetrics and Gynaecology Canada's methodology and consensus development process. VALUES: The quality of evidence is rated using the criteria described in the report of the Canadian Task Force on the Periodic Health Examination. Recommendations for practice are ranked according to the method described in this report. SPONSORS: The development of this consensus guideline was supported by unrestricted educational grants from Berlex Canada Inc., Lilly Canada, Merck Frosst, Novartis, Novogen, Novo Nordisk, Proctor and Gamble, Schering Canada, and Wyeth Canada.

Female↗

Treating osteoporosis: economic aspects of bisphosphonate therapy.

Each year, fractures associated with osteoporosis place a significant burden on healthcare spending and result in unnecessary morbidity, mortality and reductions in quality of life for individual patients. Several treatments are available that can improve the course of this chronic bone disease, and lead to significant reductions in fractures. Bisphosphonates have proven efficacy, are widely available and currently recommended as the first-line of therapy for osteoporosis in many practice guidelines. In addition to demonstrating clinical benefit, from a health-policy perspective, the economic benefits regarding prevention and treatment must be established. In recent years, several health economic studies have examined the cost-effectiveness and cost-utility of bisphosphonates in various patient groups. This paper reviews a number of these studies regarding the economic benefits of treating osteoporosis with bisphosphonates and considers for whom prevention and/or treatment is most warranted.

Cost-Benefit Analysis↗

Determinants of health-related quality of life in women with vertebral fractures.

Health-related quality of life (HRQL) is an important consideration in the management of patients with vertebral fractures. The purpose of this study was to examine patient-related factors that contribute to HRQL after vertebral fractures, including co-morbidities, medications, fracture history, family disease history, demographics, exercise, education and living environment. A total of 1,129 post-menopausal women (mean age 67.2, SD 11.9 years) was studied from the Canadian Database of Osteoporosis and Osteopenia (CANDOO). HRQL was measured using the mini-osteoporosis quality of life questionnaire (mini-OQLQ). Separate multivariable linear regression analyses [parameter estimates and corresponding 95% confidence intervals (CI)] were performed for each of the five mini-OQLQ domains: symptoms, physical functioning, emotional functioning, activities of daily living and leisure domains. A strong positive association was found between HRQL and post-secondary education, a family history of osteoporosis, working and thiazide therapy. Exercise improved HRQL; however, several hours a week were required to be meaningful. Living in long-term care had the most marked negative effect on HRQL. Smoking, past surgery of the hip or spine, sedatives, anticonvulsants, atherosclerotic disease and hypertension were also associated with a substantially decreased HRQL across several domains. Calcium channel-blockers, chemotherapy, corticosteroids, diabetes, migraines, the number of non-vertebral fractures and falls had a negative impact on selected domains. We demonstrated that several modifiable factors influence HRQL in patients with vertebral fractures, and physicians should be aware of these and other markers of reduced HRQL to enhance patient care.

Activities of Daily Living↗

Evaluation of easily measured risk factors in the prediction of osteoporotic fractures.

BACKGROUND: Fracture represents the single most important clinical event in patients with osteoporosis, yet remains under-predicted. As few premonitory symptoms for fracture exist, it is of critical importance that physicians effectively and efficiently identify individuals at increased fracture risk. METHODS: Of 3426 postmenopausal women in CANDOO, 40, 158, 99, and 64 women developed a new hip, vertebral, wrist or rib fracture, respectively. Seven easily measured risk factors predictive of fracture in research trials were examined in clinical practice including: age (< 65, 65-69, 70-74, 75-79, 80+ years), rising from a chair with arms (yes, no), weight (< 57, > or = 57 kg), maternal history of hip fracture (yes, no), prior fracture after age 50 (yes, no), hip T-score (> -1, -1 to > -2.5, < or = -2.5), and current smoking status (yes, no). Multivariable logistic regression analysis was conducted. RESULTS: The inability to rise from a chair without the use of arms (3.58; 95% CI: 1.17, 10.93) was the most significant risk factor for new hip fracture. Notable risk factors for predicting new vertebral fractures were: low body weight (1.57; 95% CI: 1.04, 2.37), current smoking (1.95; 95% CI: 1.20, 3.18) and age between 75-79 years (1.96; 95% CI: 1.10, 3.51). New wrist fractures were significantly identified by low body weight (1.71, 95% CI: 1.01, 2.90) and prior fracture after 50 years (1.96; 95% CI: 1.19, 3.22). Predictors of new rib fractures include a maternal history of a hip fracture (2.89; 95% CI: 1.04, 8.08) and a prior fracture after 50 years (2.16; 95% CI: 1.20, 3.87). CONCLUSION: This study has shown that there exists a variety of predictors of future fracture, besides BMD, that can be easily assessed by a physician. The significance of each variable depends on the site of incident fracture. Of greatest interest is that an inability to rise from a chair is perhaps the most readily identifiable significant risk factor for hip fracture and can be easily incorporated into routine clinical practice.

Aged↗

Measurement of cervical flexor endurance following whiplash.

AIM: To investigate measurement properties of a practical test of cervical flexor endurance (CFE) in whiplash patients including inter-rater reliability, sensitivity to clinical change, criterion related validity against the Neck Disability Index (NDI), and discriminant validity for injured versus uninjured populations. METHODS: Two samples were recruited, 81 whiplash patients, and a convenience sample of 160 subjects who were not seeking treatment and met criteria for normal pain and range of motion. CFE was measured using a stopwatch while the subject, in crook lying, held their head against gravity to fatigue. RESULTS: Inter-rater reliability in whiplash patients was in a range considered 'almost perfect' (Intraclass Correlation=0.96). CFE had greater inter-subject variability than the NDI or range of motion in any of three planes. However, the effect size for improvement in CFE over treatment was as large as the effect sizes for all of those measures. In multivariate regression, CFE changes accounted for changes on the NDI better than the three ranges of motion. CFE discriminated whiplash patients who were within six months of injury (n=71) from age and gender matched normals with high effect size (ES=1.5). CONCLUSIONS: These findings provide evidence of reliability and validity for CFE measurement, and demonstrate that CFE detects clinical improvements. Variance on CFE emphasizes the need to consider inter-, and intra-subject standard deviations to interpret scores.

Adolescent↗

Does alendronate reduce the risk of fracture in men? A meta-analysis incorporating prior knowledge of anti-fracture efficacy in women.

BACKGROUND: Alendronate has been found to reduce the risk of fractures in postmenopausal women as demonstrated in multiple randomized controlled trials enrolling thousands of women. Yet there is a paucity of such randomized controlled trials in osteoporotic men. Our objective was to systematically review the anti-fracture efficacy of alendronate in men with low bone mass or with a history of prevalent fracture(s) and incorporate prior knowledge of alendronate efficacy in women in the analysis. METHODS: We examined randomized controlled trials in men comparing the anti-fracture efficacy of alendronate to placebo or calcium or vitamin D, or any combination of these. Studies of men with secondary causes of osteoporosis other than hypogonadism were excluded. We searched the following electronic databases (without language restrictions) for potentially relevant citations: Medline, Medline in Process (1966-May 24/2004), and Embase (1996-2004). We also contacted the manufacturer of the drug in search of other relevant trials. Two reviewers independently identified two trials (including 375 men), which met all inclusion criteria. Data were abstracted by one reviewer and checked by another. Results of the male trials were pooled using Bayesian random effects models, incorporating prior information of anti-fracture efficacy from meta-analyses of women. RESULTS: The odds ratios of incident fractures in men (with 95% credibility intervals) with alendronate (10 mg daily) were: vertebral fractures, 0.44 (0.23, 0.83) and non-vertebral fractures, 0.60 (0.29, 1.44). CONCLUSION: In conclusion, alendronate decreases the risk of vertebral fractures in men at risk. There is currently insufficient evidence of a statistically significant reduction of non-vertebral fractures, but the paucity of trials in men limit the statistical power to detect such an effect.

Adult↗

Do hip protectors decrease the risk of hip fracture in institutional and community-dwelling elderly? A systematic review and meta-analysis of randomized controlled trials.

Hip fractures are an important cause of morbidity and mortality in the elderly. Hip protectors are padded undergarments designed to decrease the impact of a fall on the hip. We systematically reviewed randomized controlled trials of hip protectors to determine if they reduce hip fractures in the elderly. Analyses were pooled according to participant residence--community or institutional (the latter, included nursing homes, residential group homes or seniors' hostels). We included individually randomized and statistically adjusted cluster randomized trials. Seven trials of 12- to 28-month duration were included. The Safehip brand of hip protector was used in most studies. Compliance rates in the treatment groups varied from 31 to 68%. In four trials including a total of 5,696 community-dwelling seniors, the hip fracture rates in control groups ranged from 1.1 to 7.4%, and the pooled risk difference with hip protector allocation was 0% [95% confidence intervals (CI), -1%, +1%), with a relative risk of 1.07 (0.81, 1.42). In three trials including 1,188 institutionalized elderly participants, hip fracture rates in the control groups varied from 8 to 19.4%, and the pooled risk difference for sustaining one or more hip fractures with hip protector allocation was -3.7% (95% CI, -7.4%, 0.1%), with a relative risk of 0.56 (0.31, 1.01) (with statistically significant heterogeneity of treatment effect). In a post-hoc subgroup analysis of two trials comprised of exclusively nursing home residents, the risk difference with hip protector allocation was -4.4% (-8.09, -0.76) with a relative risk of 0.50 (0.28, 0.91) (n=1,014). Thus, there is little evidence to support the use of hip protectors outside the nursing home setting. The potential benefit of hip protectors in reducing hip fractures in nursing home residents requires further confirmation.

Activities of Daily Living↗

In whom and how to prevent glucocorticoid-induced osteoporosis.

Glucocorticoid use is widespread in medicine. While it is often life-saving, side-effects are well known. The most common side-effect is osteoporosis. Today we have therapies with proven efficacy for the prevention of vertebral fractures and bone loss. Consequently recognition of glucocorticoid-induced osteoporosis is extremely important given the availability of effective therapy.

Bone Density↗

Are oral bisphosphonates effective in improving lumbar bone mineral density in breast cancer survivors with osteopenia or osteoporosis?

OBJECTIVE: Breast cancer survivors with osteoporosis or osteopenia are commonly encountered in primary care and gynaecology practices. Our objective was to determine whether treatment with oral bisphosphonates (alendronate or cyclic etidronate) was more effective than calcium with vitamin D in improving lumbar spine bone mineral density (BMD) within one year in breast cancer survivors. METHODS: Breast cancer survivors with at least one year of clinical follow-up were identified from the prospective observational Canadian Database of Osteoporosis and Osteopenia (CANDOO). Analysis of covariance was used to examine the effects of bisphosphonate therapy on change in lumbar spine BMD at one year compared with the effects of calcium with vitamin D (analysis adjusted for baseline L2-L4 BMD, current tamoxifen use, number of prevalent vertebral fractures [VFs], and time since diagnosis of breast cancer, and age). RESULTS: Eighteen patients took calcium and vitamin D, 25 took cyclic etidronate, and 27 took oral alendronate. Adjusted one-year BMD increases for alendronate and cyclic etidronate compared to calcium and vitamin D were as follows: alendronate 4.53% (95% confidence interval [CI] 1.26%, 7.81%, P = 0.008), and cyclic etidronate 1.85% (-1.55%, 5.25%, P = 0.280). BMD increases were significantly greater in patients with prevalent VF compared to those without VF (P = 0.025). In contrast, time since diagnosis of breast cancer was significantly associated with a decrease in BMD (P = 0.002). We were unable to detect any effect of current tamoxifen use, baseline lumbar spine BMD, or age on changes in BMD at one year. CONCLUSION: Treatment with alendronate was associated with significantly greater improvements in lumbar spine BMD within one year in breast cancer survivors when compared with treatment with cyclic etidronate or calcium and vitamin D.

Aged↗

A systematic review of the effect of alendronate on bone mineral density in men.

Alendronate is known to increase bone mineral density (BMD) at the lumbar spine and hip in women, but less information is available in men. We conducted a systematic review of randomized controlled trials to determine whether oral alendronate improves BMD at the lumbar spine and hip in men with low bone mass or prevalent fractures, compared with men treated with placebo, calcium, or vitamin D. In three trials in men, BMD (measured by dual-energy X-ray absorptiometry) increased at 2-3 yr (compared to baseline) at the lumbar spine and femoral neck in alendronate-treated patients compared to controls. The pooled estimates of changes in BMD with 10 mg of alendronate daily compared to controls were as follows: 7.8% over 2-3 yr (95% confidence interval [CI] = 4.8- 10.8) at the lumbar spine and 3.8% (95% CI = 2.3-5.3) at the femoral neck (p < 0.001 for treatment effect in each analysis). Statistically significant heterogeneity of treatment effect was noted between trials. We conclude that 10 mg of oral daily alendronate is significantly associated with increase in BMD at the lumbar spine and hip in men over 2-3 yr and that these changes are similar to those previously observed in postmenopausal women.

Alendronate↗