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Kerry Siminoski

Publications and source records attributed to Kerry Siminoski.

12 recordsLinked to original sources
PubMed2007

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↗
PubMed2007

Osteoporosis-related kyphosis and impairments in pulmonary function: a systematic review.

UNLABELLED: We conducted a systematic review to examine the relationship between osteoporotic vertebral fractures, kyphosis, and pulmonary function. Findings suggest modest but predictable declines in vital capacity related to the degree of kyphosis. However, there were only four studies, and all had significant methodologic limitations. Further high-quality research is needed. INTRODUCTION: Our objective was to systematically review the extent to which osteoporosis-related vertebral fractures and kyphosis affect pulmonary function. MATERIALS AND METHODS: We used a literature search from 1966 to 2006 (using Medline, EMBASE, and hand searches of references) for studies examining pulmonary function in patients without known lung disease who had vertebral fractures or kyphosis secondary to osteoporosis. Two reviewers independently abstracted data. Heterogeneity precluded formal meta-analysis. RESULTS: Initial searches yielded 453 articles. After applying eligibility criteria, only four case-control studies of limited quality (e.g., only one study was blinded) remained. Since 1966, only 109 patients (6 men) have been studied. All four studies reported reductions in vital capacity (VC), with values ranging from 68% to 94% of predicted values. This was quantified as a 9% reduction in predicted VC per vertebral fracture in one study. The degree of kyphosis clinically (one study) or radiographically (three studies) correlated with declines in VC; impairments were most notable at kyphotic angles>55 degrees. Statistically significant differences in percent predicted VC were obtained only when arm span or recalled height, rather than measured height, was used (two studies). CONCLUSIONS: Despite conventional teaching, the evidence relating osteoporotic vertebral fractures or kyphosis to pulmonary function is limited. On the basis of available studies, declines in VC secondary to kyphosis seem modest and directly related to the number of vertebral fractures or degree of kyphosis. Future studies need longitudinal follow-up of larger numbers of men and women, appropriate proxies for height, standardized measures for pulmonary function and kyphosis, and efforts to blind outcomes ascertainment.

Female↗
PubMed2006

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↗
PubMed2006

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↗
PubMed2005

Randomized trial of etidronate plus calcium and vitamin D for treatment of low bone mineral density in Crohn's disease.

BACKGROUND & AIMS: Crohn's disease causes an increase in osteopenia and osteoporosis. This study assessed the efficacy of adding etidronate to calcium and vitamin D supplementation for treatment of low bone mineral density in Crohn's disease. METHODS: One hundred fifty-four patients with Crohn's disease with decreased bone mineral density, determined by using dual-energy x-ray absorptiometry, were randomly assigned to receive etidronate (400 mg orally) or not for 14 days; both groups were then given daily calcium (500 mg) and vitamin D (400 IU) supplementation for 76 days. This cycle was repeated 8 times during a period of 24 months. Biochemical characteristics and bone mineral densities were assessed at 6, 12, and 24 months. RESULTS: After 24 months bone mineral density significantly increased from baseline in both the etidronate- and the non-etidronate-treated groups (both groups receiving calcium and vitamin D supplementation) at the lumbar spine (P < .001), ultradistal radius (P < .001), and trochanter (P = .004) sites, but not at the total hip. The increase in bone mineral density was similar in each treatment group. No bone mineral density differences were found when groups were analyzed according to gender, corticosteroid use, bone mineral density at baseline, or age. CONCLUSIONS: Low bone mineral density is frequently associated with Crohn's disease. Supplementation with daily calcium and vitamin D is associated with increases in bone mineral density. The addition of oral etidronate does not further enhance bone mineral density.

Absorptiometry, Photon↗
PubMed2005

Recommendations for bone mineral density reporting in Canada.

OBJECTIVE: To propose a set of recommendations for optimal bone mineral density (BMD) reporting in postmenopausal women and older men and to provide clinicians with both a BMD diagnostic category and a useful tool to assess an individual's risk of osteoporotic fracture. OPTIONS: The current methods of BMD reporting were reviewed. In this document, we propose that an individual's 10-year absolute fracture risk, rather than BMD alone, be used for fracture risk categorization. Consequently, age, sex, BMD, fragility fracture history, and glucocorticoid use are the basis for the approach outlined in this document. OUTCOMES: An optimal BMD report as proposed in this document will provide clinicians with both a BMD diagnostic category and a useful tool to assess an individual's risk of osteoporotic fracture. A BMD report format, a checklist, and a patient questionnaire are meant to further encourage its use. EVIDENCE: All recommendations were developed using a consensus from clinicians and experts in the field of BMD testing and a standard method for the evaluation and citation of the supporting evidence. VALUES: These recommendations were developed by a multidisciplinary working group under the auspices of the Scientific Advisory Council of the Osteoporosis Society of Canada and the Canadian Association of Radiologists. BENEFITS, HARM, AND COSTS: Optimal BMD reports help the practitioner to assess an individual's risk for osteoporotic fracture and to decide whether medical therapy is warranted. RECOMMENDATIONS: The BMD report should include: patient identifiers. Dual-energy X-ray absorptiometry (DXA) scanner identifier. BMD results expressed in absolute values (g/cm2; 3 decimal places) and T-score (1 decimal place) for lumbar spine; proximal femur (total hip, femoral neck, and trochanter); and an alternate site (forearm BMD preferred: 1/3 radius, 33% radius or proximal radius) if either hip or spine is not valid. A statement about any limitations due to artifacts, if present. The fracture risk category (low, moderate, or high) as determined by using Tables 3 and 4 and by including major clinical factors that modify absolute fracture risk probability (with an indication of the corresponding absolute 10-year fracture risk of <10%, 10-20%, or >20%). A statement as to whether the change is statistically significant or not for serial measurements. The BMD centre's least significant change for each skeletal site (in g/cm2) should be included. VALIDATION: Recommendations were based on consensus opinion. Since these are the first Canadian recommendations integrating clinical risk factors in a quantitative fracture risk assessment, it is anticipated that these "Recommendations for BMD Reporting in Canada" will be a work in progress and will be updated periodically to accommodate advances in this field.

Absorptiometry, Photon↗
PubMed2004

Influence of fracture history and bone mineral density testing on the treatment of osteoporosis in two non-academic community centers.

A history of fracture and a low bone mineral density (BMD) are the strongest predictors of future osteoporotic fracture. This prospective cohort study assessed the impact of these two factors on treatment patterns in women undergoing their first BMD testing in a non-academic community setting. Successive women seen for first BMD testing at two testing centers completed a baseline questionnaire and a mailed 3-month follow-up questionnaire. Patients were grouped by history of fracture after age 20 years (present, absent) and by BMD result [osteoporosis (OP), osteopenia (OPN), normal BMD]. Thirty percent of 1144 patients at least 45 years old reported a history of fracture after age 20 years. They were no more likely than those without a history of fracture to be taking calcium (52% of total), vitamin D (31%), estrogen (31%), or a bisphosphonate (2%) before BMD testing. The BMD testing revealed OP in 20%, OPN in 45%, and normal BMD in 35%. Three months later, the percentages of patients taking treatments differed as follows: calcium (66 vs 53% in OP and OPN groups vs normal BMD), vitamin D (46 vs 37% in OPN group vs normal BMD), estrogen (25 vs 36 vs 44% in groups with OP, OPN, and normal BMD), a bisphosphonate (43 vs 11 vs 1%), and at least one of estrogen or a bisphosphonate (58 vs 43 vs 46%). Treatment decisions were influenced by first BMD testing but not significantly by a history of fracture. There is a substantial care gap in the treatment of patients with OP: either bisphosphonate or estrogen therapy was taken by only 31% of patients at least 45 years old and with a history of fracture after age 20 years before BMD testing and by only 58% of these and who also had OP by BMD.

Adult↗
PubMed2004

Risk factors associated with incident clinical vertebral and nonvertebral fractures in postmenopausal women: the Canadian Multicentre Osteoporosis Study (CaMos).

Utilizing data from the Canadian Multicentre Osteoporosis Study (CaMos), we examined the association between potential risk factors and incident vertebral and nonvertebral fractures. A total of 5,143 postmenopausal women were enrolled. Information collected during the study included data from the CaMos baseline and annually mailed fracture questionnaires, the Short Form 36 (SF-36), the Health Utilities Index, and physical measurements. Participants were followed for 3 years. Postmenopausal women were classified into four groups according to their incident fracture status since baseline: those without a new fracture; those with a new clinically recognized vertebral fracture; those with an incident nonvertebral fracture at the wrist, hip, humerus, pelvis, or ribs (main nonvertebral fracture group); and those with any new nonvertebral fracture (any-nonvertebral-fracture group). We performed multivariate Cox proportional hazard analysis using all possible risk factors to determine the association between risk factors and the time to the first minimal trauma fracture. Best predictive models were also determined using variables that were included in the full models. The Bayesian information criterion was used for model selection. For all analyses, relative risks and associated 95% confidence intervals were calculated. During the follow-up period, 34, 163, and 280 women developed a vertebral, a main nonvertebral, or any nonvertebral fracture, respectively. The best predictive models indicated that a five point lower quality of life as measured by the SF-36 physical component summary score was associated with relative risks of 1.21 (95% CI, 1.02 to 1.44), 1.17 (95% CI, 1.07 to 1.28), and 1.19 (95% CI, 1.11 to 1.27) for incident vertebral, main nonvertebral, and all nonvertebral fractures, respectively. In addition, for a one standard deviation (SD=0.12) lower femoral neck BMD, the relative risks for incident vertebral, main nonvertebral, and any nonvertebral fractures increased by 2.73 (95% CI, 1.74 to 4.28), 1.39 (95% CI, 1.06 to 1.82), and 1.34 (95% CI, 1.09 to 1.65), respectively. Furthermore, various anthropometric measures, disease conditions, and medications are associated with a new fracture. Identifying postmenopausal women at risk is important given that fracture prevention therapies are now available.

Adult↗
PubMed2004

Bones and Crohn's: risk factors associated with low bone mineral density in patients with Crohn's disease.

Previous studies have confirmed that the prevalence of decreased bone mineral density is elevated in patients with inflammatory bowel disease. The objective of the current study was to determine the prevalence of osteopenia and osteoporosis in a cross-sectional outpatient population of 242 adult patients with Crohn's disease and to determine which clinical characteristics and serum and urine biochemical factors might be predictive of bone loss. Thirty-seven percent had normal bone density, 50.0% were osteopenic, and 12.9% were osteoporotic. Among the sites used to diagnose low bone mineral density, the femoral neck demonstrated the highest prevalence of osteopenia and the ultra-distal radius the highest prevalence of osteoporosis. However, low bone mineral density at one site was always predictive of low bone mineral density at the other. Corticosteroid use during the year before assessment was found to be consistently predictive of low bone mineral density in males but not in females. In contrast, low body mass index and high platelet counts were consistently predictive of low bone mineral density in females but not in males. Disease location, smoking, and age were not predictive of changes in bone mineral density.

Adult↗
PubMed2003

The frequency of vitamin D deficiency in adults with Crohn's disease.

BACKGROUND: Vitamin D deficiency is a putative, pathogenic cofactor in the increase in osteopenia and osteoporosis seen in patients with Crohn's disease. OBJECTIVE: To determine the frequency of low serum 25-hydroxy-vitamin D3 (25-OHD) levels and the associated alterations in bone mineral density in a cohort of adults with Crohn's disease. METHODS: 25-OHD levels were determined in 242 consecutive patients with Crohn's disease seen in two tertiary inflammatory bowel disease referral centres. Bone mineral density was assessed by dual energy x-ray absorptiometry. RESULTS: Nineteen (8%) patients exhibited vitamin D deficiency (25-OHD less than 25 nmol/L) and 52 (22%) patients exhibited vitamin D insufficiency (25-OHD less than 40 nmol/L). Mean T-scores at the lumbar spine, femoral neck, total hip and ultradistal radius in the group with low 25-OHD did not differ from those of the normal 25-OHD group. Serum alkaline phosphatase and parathyroid hormone levels were higher in the low 25-OHD group than in the normal group. Decreased red blood cell (RBC) folate predicted low 25-OHD in male patients, while smoking, RBC folate and serum iron predicted low 25-OHD in female patients. The rate of low 25-OHD deficiency in the winter was significantly higher than that in the summer (11.9% versus 2.8%, respectively). CONCLUSION: Vitamin D-deficient Crohn's disease patients exhibit biochemical evidence of metabolic bone disease, without detectable differences in bone mineral density. Sunlight exposure, nutrition and smoking status were predictors of vitamin D deficiency in this patient cohort.

Adult↗