2018 Journal Articles by Angela M Cheung
Fracture determinants differ between Canadians of Chinese and White descent, the former constitut... more Fracture determinants differ between Canadians of Chinese and White descent, the former constituting the second largest visible minority group in Canada. The results of this study support the importance of characterizing bone health predictors in Canadians of different ethnicity to improve population-specific fracture prevention and treatment strategies. Purpose We aimed to compare clinical risk factors, bone mineral density, prevalence of osteoporosis, and fractures between Chinese and White Canadians to identify ethnicity-specific risks. Methods We studied 236 Chinese and 8945 White Canadians aged 25+ years from the Canadian Multicentre Osteoporosis Study (CaMos). The prevalence of osteoporosis using ethnicity-specific peak bone mass (PBM), and of prior and incident low trauma fractures were assessed and compared between groups. Linear regressions, adjusting for age and anthropometric measures, were used to examine the association between baseline and 5-year changes in BMD and ethnicity. Results Chinese participants had shorter stature, lower BMI, and lower rate of falls than White participants. Adjusted models showed no significant differences in baseline BMD between ethnic groups except in younger men where total hip BMD was 0.059 g/cm 2 (0.009; 0.108) lower in Chinese. Adjusted 5-year BMD change at lumbar spine was higher in older Chinese women and men compared with Whites. When using Chinese-specific PBM, the prevalence of osteoporosis in Chinese women was 2fold lower than when using that of White women The prevalence of fractures was higher in White women compared with Chinese with differences up to 14.5% (95% CI 9.2; 19.7) and 10.5% (95% CI 4.5-16.4) in older White men. Incident fractures were rare in young Chinese compared with White participants and not different in the older groups. Conclusion Our results support the importance of characterizing bone strength predictors in Chinese Canadians and the development of ethnicity-specific fracture prediction and prevention strategies.
Clinical Practice Guideline, 2019
Objective: The objective is to formulate clinical practice guidelines for the pharmacological man... more Objective: The objective is to formulate clinical practice guidelines for the pharmacological management of osteoporosis in postmenopausal women.
Conclusions: Evidence from clinical trials and insights from clinical experience with pharmacologic therapies for osteoporosis were critically evaluated in formulating this guideline for the management of postmenopausal osteoporosis. Patient preferences, data on adherence and persistence, and risks and benefits from the patient and provider perspectives were also considered in writing committee deliberations. A consensus by the Writing Committee members was achieved for four management principles: (i) The risk of future fractures in postmenopausal women should be determined using country-specific assessment tools to guide decision-making. (ii) Patient preferences should be incorporated into treatment planning. (iii) Nutritional and lifestyle interventions and fall prevention should accompany all pharmacologic regimens to reduce fracture risk. (iv) Multiple pharmacologic therapies are capable of reducing fracture rates in postmenopausal women at risk with acceptable risk-benefit and safety profiles.
High-resolution peripheral quantitative computed tomography (HR-pQCT) quantifies bone microstruct... more High-resolution peripheral quantitative computed tomography (HR-pQCT) quantifies bone microstructure and density at the distal tibia where there is also a sizable amount of myotendinous (muscle and tendon) tissue (MT); however, there is no method for the quantification of MT. This study aimed (1) to assess the feasibility of using HR-pQCT distal tibia scans to estimate MT properties using a custom algorithm, and (2) to determine the relationship between MT properties at the distal tibia and mid-leg muscle density (MD) obtained from pQCT. Postmenopausal women from the Hamilton cohort of the Canadian Multicenter Osteoporosis Study had a single-slice (2.3 ± 0.5 mm) 66% site pQCT scan measuring muscle cross-sectional area (MCSA) and MD. A standard HR-pQCT scan was acquired at the distal tibia. HR-pQCT-derived MT crosssectional area (MTCSA) and MT density (MTD) were calculated using a custom algorithm in which thresholds (34.22-194.32 mg HA/cm 3) identified muscle seed volumes and were iteratively expanded. Pearson and Bland-Altman plots were used to assess correlations and systematic differences between pQCT-and HR-pQCT-derived muscle properties. Among 45 women (mean age: 74.6 ± 8.5 years, body mass index: 25.9 ± 4.3 kg/ m 2), MTD was moderately correlated with mid-leg MD across the 2 modalities (r = 0.69-0.70, p < 0.01). Bland-Altman analyses revealed no evidence of directional bias for MTD-MD. HR-pQCT and pQCT measures of MTCSA and MCSA were moderately correlated (r = 0.44, p < 0.01). Bland-Altman plots for MTCSA revealed that larger MCSAs related to larger discrepancy between the distal and the mid-leg locations. This is the first study to assess the ability of HR-pQCT to measure MT size, density, and morphometry. HR-pQCTderived MTD was moderately correlated with mid-leg MD from pQCT. This relationship suggests that distal MT may share common properties with muscle throughout the length of the leg. Future studies will assess the value of HR-pQCT-derived MT properties in the context of falls, mobility, and balance.
We compared two methods for osteoporotic vertebral fracture (VF) assessment on lateral spine radi... more We compared two methods for osteoporotic vertebral fracture (VF) assessment on lateral spine radiographs, the Genant semiquantitative (GSQ) technique and a modified algorithm-based qualitative (mABQ) approach. We evaluated 4465 women and 1771 men aged !50 years from the Canadian Multicentre Osteoporosis Study with available X-ray images at baseline. Observer agreement was lowest for grade 1 VFs determined by GSQ. Among physician readers, agreement was greater for VFs diagnosed by mABQ (ranging from 0.62 [95% confidence interval (
The accumulation of INTERmuscular fatD 2 0 8 X X and INTRAmuscular fat (IMF) has been a hallmark ... more The accumulation of INTERmuscular fatD 2 0 8 X X and INTRAmuscular fat (IMF) has been a hallmark of individuals with diabetes, those with mobility impairments such as spinal cord injuries and is known to increase with aging. An elevated amount of IMF has been associated with fractures and frailty, but the imprecision of IMF measurement has so far limited the ability to observe more consistent clinical associations. Magnetic resonance imagingD 2 0 9 X X has been recognized as the gold standard for portraying these features, yet reliable methods for quantifying IMF on magnetic resonance imagingD 2 1 0 X X is far from standardized. Previous investigators used manual segmentation guided by histogram-based region-growing, but these techniques are subjective and have not demonstrated reliability. Others applied fuzzy classification, machine learning, and atlas-based segmentation methods, but each is limited by the complexity of implementation or by the need for a learning set, which must be established each time a new disease cohort is examined. In this paper, a simple convergent iterative threshold-optimizing algorithm was explored. The goal of the algorithm is to enable IMF quantification from plain fast spin echo (FSE) T1-weighted MR images or from water-saturated images. The algorithm can be programmed into Matlab easily, and is semiD 2 1 1 X Xautomated, thus minimizing the subjectivity of threshold-selection. In 110 participants from 3 cohort studies, IMF area measurement demonstrated a high degree of reproducibility with errors well within the 5% benchmark for intraD 2 1 2 X Xobserver, interD 2 1 3 X Xobserver, and testD 2 1 4 X XÀretest analyses; in contrast to manual segmentation which already yielded over 20% error for intraD 2 1 5 X Xobserver analysis. This algorithm showed validity against manual segmentations (r > 0.85). The simplicity of this technique lends itself to be applied to fast spin echoD 2 1 6 X X images commonly ordered as part of standard of care and does not require more advanced fat-water separated images.D 2 1 7 X X
The accumulation of INTERmuscular fatD 2 0 8 X X and INTRAmuscular fat (IMF) has been a hallmark ... more The accumulation of INTERmuscular fatD 2 0 8 X X and INTRAmuscular fat (IMF) has been a hallmark of individuals with diabetes, those with mobility impairments such as spinal cord injuries and is known to increase with aging. An elevated amount of IMF has been associated with fractures and frailty, but the imprecision of IMF measurement has so far limited the ability to observe more consistent clinical associations. Magnetic resonance imagingD 2 0 9 X X has been recognized as the gold standard for portraying these features, yet reliable methods for quantifying IMF on magnetic resonance imagingD 2 1 0 X X is far from standardized. Previous investigators used manual segmentation guided by histogram-based region-growing, but these techniques are subjective and have not demonstrated reliability. Others applied fuzzy classification, machine learning, and atlas-based segmentation methods, but each is limited by the complexity of implementation or by the need for a learning set, which must be established each time a new disease cohort is examined. In this paper, a simple convergent iterative threshold-optimizing algorithm was explored. The goal of the algorithm is to enable IMF quantification from plain fast spin echo (FSE) T1-weighted MR images or from water-saturated images. The algorithm can be programmed into Matlab easily, and is semiD 2 1 1 X Xautomated, thus minimizing the subjectivity of threshold-selection. In 110 participants from 3 cohort studies, IMF area measurement demonstrated a high degree of reproducibility with errors well within the 5% benchmark for intraD 2 1 2 X Xobserver, interD 2 1 3 X Xobserver, and testD 2 1 4 X XÀretest analyses; in contrast to manual segmentation which already yielded over 20% error for intraD 2 1 5 X Xobserver analysis. This algorithm showed validity against manual segmentations (r > 0.85). The simplicity of this technique lends itself to be applied to fast spin echoD 2 1 6 X X images commonly ordered as part of standard of care and does not require more advanced fat-water separated images.D 2 1 7 X X
Osteoporosis International, 2018
Knowledge exchange with community-dwelling individuals across Ontario revealed barriers to implem... more Knowledge exchange with community-dwelling individuals across Ontario revealed barriers to implementation of physical activity recommendations that reflected capability, opportunity, and motivation; barriers unique to individuals with osteoporosis include fear of fracturing, trust in providers, and knowledge of exercise terminology. Using the Behaviour Change Wheel, we identified interventions (training, education, modeling) and policy categories (communication/marketing, guidelines, service provision). Introduction Physical activity recommendations exist for individuals with osteoporosis; however, to change behavior, we must address barriers and facilitators to their implementation. The purposes of this project are (1) to identify barriers to and facilitators of uptake of disease-specific physical activity recommendations (2) to use the findings to identify behavior change strategies using the Behaviour Change Wheel (BCW). Methods Focus groups and semi-structured interviews were conducted with community-dwelling individuals attending osteoporosis-related programs or education sessions in Ontario. They were stratified by geographic area, urban/rural, and gender, and transcribed verbatim. Two researchers coded data and identified emerging themes. Using the Behaviour Change Wheel framework, themes were categorized into capability, opportunity, and motivation, and interventions were identified. Results Two hundred forty community-dwelling individuals across Ontario participated (mean ± SD age = 72 ± 8.28). Barriers were as follows: capability: disease-related symptoms hinder exercise and physical activity participation, lack of exercise-related knowledge, low exercise self-efficacy; opportunity: access to exercise programs that meet needs and preferences, limited resources and time, physical activity norms and preferences; motivation: incentives to exercise, fear of fracturing, trust in exercise providers. Interventions selected were training, education, and modeling. Policy categories selected were communication/marketing, guidelines, and service provision. Conclusions Barriers unique to individuals with osteoporosis included the following: lack of knowledge on key exercise concepts, fear of fracturing, and trust in providers. Behavior change techniques may need tailoring to gender, age, or presence of comorbid conditions.
(Deok Hyun Jang) significant change in measured SI values with respect to the concentration of al... more (Deok Hyun Jang) significant change in measured SI values with respect to the concentration of all three elements was observed, for both the clinical and research QUS systems.
2017 Journal Articles by Angela M Cheung
The purpose of this cross-sectional study was to determine how appendicular lean mass index (ALMI... more The purpose of this cross-sectional study was to determine how appendicular lean mass index (ALMI), and whole body lean (LMI) and fat mass indices (FMI) associate with estimated bone strength outcomes at the distal radius and tibia in adults aged 40 years and older. Methods: Dual energy X-ray absorptiometry (DXA) scans were performed to determine body composition, including whole body lean and fat mass, and appendicular lean mass. ALMI (appendicular lean mass/height 2), LMI (lean tissue mass/height 2) and FMI (fat mass/height 2) were calculated. High-resolution peripheral quantitative computed tomography (HRpQCT) scans were performed to assess bone structural properties at the distal radius and tibia. Using finite element analysis, failure load (N), stiffness (N/mm), ultimate stress (MPa), and cortical-to-trabecular load ratio were estimated from HRpQCT scans. The associations between body composition (ALMI, LMI, FMI) and estimated bone strength were examined using bivariate and multivariable linear regression analyses adjusting for age, sex, and other confounding variables. Results: In 197 participants (127 women; mean ± SD, age: 69.5 ± 10.3 y, body mass index: 27.95 ± 4.95 kg/m 2 , ALMI: 7.31 ± 1.31 kg/m 2), ALMI and LMI were significantly associated with failure load at the distal radius and tibia (explained 39%-48% of the variance) and remained significant after adjusting for confounding variables and multiple testing (R 2 = 0.586-0.645, p b 0.001). ALMI, LMI, and FMI did not have significant associations with ultimate stress in our multivariable models. FMI was significantly associated with cortical-to-trabecular load ratio at the distal radius and tibia (explained 6%-12% of the variance) and remained significant after adjusting for confounders and multiple testing (R 2 = 0.208-0.243, p b 0.001). FMI was no longer significantly associated with failure load after adjusting for confounders. Conclusion: These findings suggest that ALMI and LMI are important determinants of estimated bone strength, particularly failure load, at the distal radius and tibia, and may contribute to preservation of bone strength in middle-to-late adulthood.
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2018 Journal Articles by Angela M Cheung
Conclusions: Evidence from clinical trials and insights from clinical experience with pharmacologic therapies for osteoporosis were critically evaluated in formulating this guideline for the management of postmenopausal osteoporosis. Patient preferences, data on adherence and persistence, and risks and benefits from the patient and provider perspectives were also considered in writing committee deliberations. A consensus by the Writing Committee members was achieved for four management principles: (i) The risk of future fractures in postmenopausal women should be determined using country-specific assessment tools to guide decision-making. (ii) Patient preferences should be incorporated into treatment planning. (iii) Nutritional and lifestyle interventions and fall prevention should accompany all pharmacologic regimens to reduce fracture risk. (iv) Multiple pharmacologic therapies are capable of reducing fracture rates in postmenopausal women at risk with acceptable risk-benefit and safety profiles.
2017 Journal Articles by Angela M Cheung
Conclusions: Evidence from clinical trials and insights from clinical experience with pharmacologic therapies for osteoporosis were critically evaluated in formulating this guideline for the management of postmenopausal osteoporosis. Patient preferences, data on adherence and persistence, and risks and benefits from the patient and provider perspectives were also considered in writing committee deliberations. A consensus by the Writing Committee members was achieved for four management principles: (i) The risk of future fractures in postmenopausal women should be determined using country-specific assessment tools to guide decision-making. (ii) Patient preferences should be incorporated into treatment planning. (iii) Nutritional and lifestyle interventions and fall prevention should accompany all pharmacologic regimens to reduce fracture risk. (iv) Multiple pharmacologic therapies are capable of reducing fracture rates in postmenopausal women at risk with acceptable risk-benefit and safety profiles.
Methods: Eight focus groups were conducted with 46 immigrant women, 24 from Mainland China and 22 from India, who had lived less than 5 years in Canada. Audiotaped data were transcribed, translated and analyzed by identification of themes and subcategories within and between groups.
Results: In both ethnic groups, discussions on promoting health messages had five major themes, i.e., sources, barriers, facilitators, credibility and ways to improve access along with group specific sub-themes. Despite identification of several diverse sources of health information in the adopted country, Indian and Chinese immigrant women perceived most strategies as not very effective. The reasons of perceived ineffectiveness were barriers to accessing and comprehending the health messages; and limited prior exposure to institution based or formal health promotion initiatives. These women were more familiar with informal means of obtaining health information such as social networks, mass media and written materials in their mother tongue.
Conclusion: Existing health communication and health promotion models need to be re-orientated from a one-way information flow to a two-way dialogue model to bridge the gap between program efficacy and effectiveness to reach underserved immigrant women. An "outside the box" approach of non-institutional informal health promotion strategies needs to be tested for the studied groups.
illness referred to as post COVID-19 conditions. The objective of this living systematic review is
to document the prevalence of post COVID-19 conditions 4-12 weeks (short-term) and >12 weeks (longterm) after COVID-19 diagnosis.
Methods: We conducted a systematic review of primary peer-reviewed published literature reporting
on the prevalence of the symptoms, sequelae and difficulties conducting usual activities ≥4 weeks after
COVID-19 diagnosis. We adapted a previous search strategy used by the U.K. National Institute for
Health and Care Excellence and updated it to search for new research published until January 15, 2021
in Embase, Medline, PsychInfo, and Cochrane Central. Two independent reviewers screened references;
one reviewer extracted data and assessed risk of bias and certainty in the evidence while another
verified them. Prevalence data from laboratory-confirmed individuals were meta-analyzed, where
appropriate, using a random effects model and synthesized separately in the short- and long-term
periods after COVID-19 diagnosis; data from clinically-diagnosed populations were synthesized
narratively.
Results: Of the 2807 unique citations, 36 observational studies met our inclusion criteria. Over 100 post
COVID-19 conditions were reported in laboratory-confirmed individuals. Eighty-three percent (95%CI:
65-93%; low certainty) and 56% (95%CI: 34-75%; very low certainty) reported persistence or presence of
one or more symptoms in the short- and long-term, respectively. The most prevalent symptoms in both
periods included: fatigue, general pain or discomfort, sleep disturbances, shortness of breath and
anxiety or depression (point estimates ranging from 22-51%; low to very low certainty).
Interpretation: Our data indicate that a substantial proportion of individuals reported a variety of
symptoms ≥4 weeks after COVID-19 diagnosis. Due to low certainty in the evidence, further research is
needed to determine the true burden of post COVID-19 conditions.
Objective: To examine the comparative risks of drug holidays after long-term (≥3 years) risedronate versus alendronate therapy.
Design: Population-based, matched, cohort study.
Setting: Province-wide health care administrative databases providing comprehensive coverage to Ontario residents aged 65 years or older between November 2000 and March 2020.
Patients: Persons aged 66 years or older who had long-term risedronate therapy and a drug holiday were matched 1:1 on propensity score to those who had long-term alendronate therapy and a drug holiday.
Measurements: The primary outcome was hip fracture within 3 years after a 120-day ascertainment period. Secondary analyses included shorter follow-up and sex-specific estimates. Cox proportional hazards models were used to estimate hazard ratios (HRs) for fracture risk between groups.
Results: A total of 25 077 propensity score-matched pairs were eligible (mean age, 81 years; 81% women). Hip fracture rates were higher among risedronate than alendronate drug holidays (12.4 and 10.6 events, respectively, per 1000 patient-years; HR, 1.18 [95% CI, 1.04 to 1.34]; 915 total hip fractures). The association was attenuated when any fracture was included as the outcome (HR, 1.07 [CI, 1.00 to 1.16]) and with shorter drug holidays (1 year: HR, 1.03 [CI, 0.85 to 1.24]; 2 years: HR, 1.14 [CI, 0.96 to 1.32]).
Limitation: Analyses were limited to health care administrative data (potential unmeasured confounding), and some secondary analyses contained few events.
Conclusion: Drug holidays after long-term therapy with risedronate were associated with a small increase in risk for hip fracture compared with alendronate drug holidays. Future research should examine how best to mitigate this risk.
Primary funding source: Canadian Institutes of Health Research.