Background
Osteoporosis is generally thought of as a “woman’s disease” because the prevalence of osteoporosis and the rate of fractures are much higher in postmenopausal women than in older men. ...However, the absolute number of men affected by osteoporosis and fractures is large, as at least 2.8 million men in the United States are thought to have osteoporosis.
Questions/purposes
The purposes of this review are to (1) highlight gender differences in osteoporosis and fracture risk, (2) describe disparities in treatment and outcomes after fractures between men and women, and (3) propose solutions to reducing disparities in treatment and prevention.
Methods
A literature survey was conducted using MEDLINE with a variety of search terms and using references from the author’s personal collection of articles. A formal search strategy and exclusion criteria were not employed and the review is therefore selective.
Where are we now?
Postmenopausal women have a higher prevalence of osteoporosis and greater incidence of fracture than older men. Despite the higher fracture risk in postmenopausal women, older men tend to have worse outcomes after fracture and poorer treatment rates, although less is known about the disease course in men. Multifaceted interventions to improve the screening and treatment for osteoporosis were recently developed.
Where do we need to go?
Improvement in treatment rates of those at risk, regardless of gender, is an important goal in osteoporosis management.
How do we get there?
Further development and evaluation of cost-effective, multifaceted interventions for screening and treatment of osteoporosis and fractures are needed; such interventions will likely improve the primary prevention of fractures.
This review provides a description of the assessment of lean mass and physical performance with particular attention to how these measures are used in the context of sarcopenia, in both research and ...clinical settings. One of the most common methods to estimate muscle mass is whole-body dual-energy X-ray absorptiometry (DXA). DXA estimates the total amount of lean tissue but does not directly measure muscle mass. Appendicular lean mass (ALM), derived from DXA scans, is the sum of the lean tissue in the arms and legs. ALM alone, or scaled to height squared (ALM/height(2)) or body mass index (ALM/body mass index), is the most common metric used as an approximation of muscle mass in sarcopenia research. Other methods to assess muscle mass include central or peripheral quantitative computed tomography (to determine muscle cross-sectional area and muscle density, a marker of fat i nfiltration into the muscle); magnetic resonance (to assess muscle cross-sectional area and volume); and bioelectrical impedance analysis (to determine fat-free mass). Many approaches to objectively measuring physical performance have been used in sarcopenia research. Muscle strength is often measured: Grip strength is very inexpensive and straightforward to assess, whereas assessment of lower extremity strength is more difficult. However, lower extremity strength may be a more relevant measure than grip strength in the context of mobility outcomes. Dynamic physical performance is also widely measured in research settings and may be emerging as a routine assessment in clinical care. The most widely used measure of physical performance is walking speed over a short distance, usually 3-6 m. Other measures of objective physical performance include the Short Physical Performance Battery that includes gait speed, ability and time to rise from a chair 5 times, and static balance tests; and the Timed Up and Go test that measures the time to rise from a chair and walk a short distance. Finally, longer distance walking tests are also used. "Fast" versions of these tests measure either distance traveled in a set amount of time (as for the 6-minute walk test) or time to walk a set distance (such as the fast long distance corridor walk more than 400 m). The "usual pace" version of the longer distance walking test, the usual-pace 400 m walk, is an objective measure of disability and has been used as an outcome in clinical trials. In summary, there are many methods available to assess muscle mass and physical function, each with advantages and limitations. The choice of what test to use depends on the nature of the research question or the clinical environment and the availability of resources for evaluation.
Low muscle mass and weakness are common and potentially disabling in older adults, but in order to become recognized as a clinical condition, criteria for diagnosis should be based on clinically ...relevant thresholds and independently validated. The Foundation for the National Institutes of Health Biomarkers Consortium Sarcopenia Project used an evidence-based approach to develop these criteria. Initial findings were presented at a conference in May 2012, which generated recommendations that guided additional analyses to determine final recommended criteria. Details of the Project and its findings are presented in four accompanying manuscripts.
The Foundation for the National Institutes of Health Sarcopenia Project used data from nine sources of community-dwelling older persons: Age, Gene/Environment Susceptibility-Reykjavik Study, Boston Puerto Rican Health Study, a series of six clinical trials, Framingham Heart Study, Health, Aging, and Body Composition, Invecchiare in Chianti, Osteoporotic Fractures in Men Study, Rancho Bernardo Study, and Study of Osteoporotic Fractures. Feedback from conference attendees was obtained via surveys and breakout groups.
The pooled sample included 26,625 participants (57% women, mean age in men 75.2 ±6.1 SD and in women 78.6 ±5.9 years). Conference attendees emphasized the importance of evaluating the influence of body mass on cutpoints. Based on the analyses presented in this series, the final recommended cutpoints for weakness are grip strength <26kg for men and <16kg for women, and for low lean mass, appendicular lean mass adjusted for body mass index <0.789 for men and <0.512 for women.
These evidence-based cutpoints, based on a large and diverse population, may help identify participants for clinical trials and should be evaluated among populations with high rates of functional limitations.
Direct assessment of skeletal muscle mass in older adults is clinically challenging. Relationships between lean mass and late-life outcomes have been inconsistent. The D3-creatine dilution method ...provides a direct assessment of muscle mass.
Muscle mass was assessed by D3-creatine (D3Cr) dilution in 1,382 men (mean age, 84.2 years). Participants completed the Short Physical Performance Battery (SPPB); usual walking speed (6 m); and dual x-ray absorptiometry (DXA) lean mass. Men self-reported mobility limitations (difficulty walking 2-3 blocks or climbing 10 steps); recurrent falls (2+); and serious injurious falls in the subsequent year. Across quartiles of D3Cr muscle mass/body mass, multivariate linear models calculated means for SPPB and gait speed; multivariate logistic models calculated odds ratios for incident mobility limitations or falls.
Compared to men in the highest quartile, those in the lowest quartile of D3Cr muscle mass/body mass had slower gait speed (Q1: 1.04 vs Q4: 1.17 m/s); lower SPPB (Q1: 8.4 vs Q4: 10.4 points); greater likelihood of incident serious injurious falls (odds ratio OR Q1 vs Q4: 2.49, 95% confidence interval CI: 1.37, 4.54); prevalent mobility limitation (OR Q1 vs Q4,: 6.1, 95% CI: 3.7, 10.3) and incident mobility limitation (OR Q1 vs Q4: 2.15 95% CI: 1.42, 3.26); p for trend < .001 for all. Results for incident recurrent falls were in the similar direction (p = .156). DXA lean mass had weaker associations with the outcomes.
Unlike DXA lean mass, low D3Cr muscle mass/body mass is strongly related to physical performance, mobility, and incident injurious falls in older men.
Objectives
To describe the natural history of frailty transitions in a large cohort of community‐dwelling older men and identify predictors associated with progression to or improvement from states ...of greater frailty.
Design
Prospective cohort study.
Setting
Six U.S. sites.
Participants
Community‐dwelling men aged 65 and older (N = 5,086).
Measurements
Frailty was measured at baseline and an average of 4.6 years later. Frailty was defined as having three or more of the following components (low lean mass, weakness, self‐reported exhaustion, low activity level, and slow walking speed); prefrailty was defined as having one or two components. Separate multivariable logistic regression models were analyzed for progression and improvement in frailty status.
Results
Of the 5,086 men, 8% were frail, 46% were prefrail, and 46% were robust at baseline. Between baseline and follow‐up, 35% progressed in frailty status or died, 56% had no change in frailty status, and 15% of prefrail or frail participants improved, although only 0.5% improved across two levels, from frail to robust. In multivariable models, factors associated with improvement in frailty status included greater leg power, being married, and good or excellent self‐reported health, whereas presence of any instrumental activity of daily living (IADL) limitations, low albumin levels, high interleukin‐6 levels, and presence of chronic obstructive pulmonary disease or diabetes mellitus were associated with lower likelihood of improvement in frailty status.
Conclusion
Improvement in frailty status was possible in this cohort of community‐dwelling older men, but improvement from frail to robust was rare. Several predictors were identified as possible targets for intervention, including prevention and management of comorbid medical conditions, prevention of IADL disability, physical exercise, and nutritional and social support.
See related editorial by Bandeen‐Roche et al.
Objectives
To determine the association of the frailty phenotype with subsequent healthcare costs and utilization.
Design
Prospective cohort study (Study of Osteoporotic Fractures (SOF)).
Setting
...Four U.S. sites.
Participants
Community‐dwelling women (mean age 80.2) participating in SOF Year 10 (Y10) examination linked with their Medicare claims data (N=2,150).
Measurements
At Y10, frailty phenotype defined using criteria similar to those used in the Cardiovascular Health Study frailty phenotype and categorized as robust, intermediate stage, or frail. Participant multimorbidity burden ascertained using claims data. Functional limitations assessed by asking about difficulty performing instrumental activities of daily living. Total direct healthcare costs and utilization ascertained during 12 months after Y10.
Results
Mean total annualized cost±standard deviation (2014 dollars) was $3,781±6,920 for robust women, $6,632±12,452 for intermediate stage women, and $10,755 ± 16,589 for frail women. After adjustment for age, site, multimorbidity burden, and cognition, frail women had greater mean total (cost ratio (CR)=1.91, 95% confidence interval (CI)=1.59–2.31) and outpatient (CR=1.55, 95% CI=1.36–1.78) costs than robust women and greater odds of hospitalization (odds ratio (OR)=2.05, 95% CI=1.47–2.87) and a skilled nursing facility stay (OR=3.85, 95% CI=1.88–7.88). There were smaller but significant effects of the intermediate stage category on these outcomes. Individual frailty components (shrinking, poor energy, slowness, low physical activity) were also each associated with higher total costs. Functional limitations partially mediated the association between the frailty phenotype and total costs (CR further adjusted for self‐reported limitations=1.32, 95% CI=1.07–1.63 for frail vs robust; CR=1.35, 95% CI=1.18–1.55 for intermediate stage vs robust women).
Conclusion
Intermediate stage and frail older community‐dwelling women had higher subsequent total healthcare costs and utilization after accounting for multimorbidity and functional limitations. Frailty phenotype assessment may improve identification of older adults likely to require costly, extensive care.
Abstract
Background
Whether low muscle mass is a risk factor for disability and mortality is unclear. Associations between approximations of muscle mass (including lean mass from dual-energy x-ray ...absorptiometry DXA), and these outcomes are inconsistent.
Methods
Muscle mass measured by deuterated creatine (D3Cr) dilution and appendicular lean mass (ALM, by DXA) were assessed at the Year 14 Visit (2014–2016) of the prospective Osteoporotic Fractures in Men study (N = 1,425, age 77–101 years). Disability in activities of daily living (ADLs), instrumental ADLs, and mobility tasks was self-reported at the Year 14 visit and 2.2 years later; deaths were centrally adjudicated over 3.3 years. Relative risks and 95% confidence intervals (CI) were estimated per standard deviation decrement with negative binomial, logistic regression, or proportional hazards models.
Results
In age- and clinical center-adjusted models, the relative risks per decrement in D3Cr muscle mass/wgt was 1.9 (95% CI: 1.2, 3.1) for incident self-reported ADL disability; 1.5 (95% CI: 1.3, 1.9) for instrumental ADL disability; and 1.8 (95% CI: 1.5, 2.2) for mobility disability. In age-, clinical center-, and weight-adjusted models, the relative risks per decrement in D3Cr muscle mass was 1.8 (95% CI: 1.5, 2.2) for all-cause mortality. In contrast, lower DXA ALM was not associated with any outcome. Associations of D3Cr muscle mass with these outcomes were slightly attenuated after adjustment for confounding factors and the potentially mediating effects of strength and physical performance.
Conclusions
Low muscle mass as measured by D3Cr dilution is a novel risk factor for clinically meaningful outcomes in older men.
Abstract
Background
Evaluating asymmetries in muscle function could provide important insights for fall risk assessments. We sought to determine the associations of (i) handgrip strength (HGS) ...asymmetry and (ii) leg extension power (LEP) asymmetry on risk of incident recurrent falls and fractures in older men.
Method
There were 5 730 men with HGS asymmetry data and 5 347 men with LEP asymmetry data from the Osteoporotic Fractures in Men (MrOS) study. A handgrip dynamometer measured HGS and a Nottingham Power Rig ascertained LEP. Percent difference in maximal HGS between hands was calculated, and asymmetric HGS was defined as men in the highest quartile of dissimilarity for HGS between hands. The same approach was used to determine asymmetric LEP. Participants self-reported falls every 4 months after the baseline exam, and persons with ≥2 falls in the first year were considered recurrent fallers. Fractures and their dates of occurrence were self-reported and confirmed with radiographic reports.
Results
Older men in the highest HGS asymmetry quartile had a 1.20 (95% confidence interval CI: 1.01–1.43) relative risk for incident recurrent falls. Likewise, men in the highest HGS asymmetry quartile had a higher risk for incident fractures: 1.41 (CI: 1.02–1.96) for hip, 1.28 (CI: 1.04–1.58) for major osteoporotic, and 1.24 (CI: 1.06–1.45) for nonspine. There were no significant associations between LEP asymmetry and recurrent falls or fractures.
Conclusions
Asymmetric HGS could be a novel risk factor for falls and fractures that is more feasible to measure than LEP. Fall risk assessments should consider evaluating muscle function, including HGS asymmetry.
Background
Sarcopenia, a reduction in skeletal muscle mass and function, is a condition that contributes to functional decline and disability in older adults. Although research on this geriatric ...condition has developed rapidly in recent years, little work has been done to document whether practicing physicians are incorporating sarcopenia into their clinical practice.
Methods
An online survey of 253 practicing U.S. physicians assessed knowledge of sarcopenia, use of the term in practice, motivation for screening patients, and diagnostic and treatment approaches. They were board certified in four practice areas: internal medicine (n = 69), family medicine (n = 69), geriatrics (n = 40), or physical medicine and rehabilitation (PM&R) (n = 75).
Results
Less than 20% of internists and family medicine physicians reported being very familiar with the term sarcopenia, with substantially higher familiarity at this level reported among geriatricians (70%) and among PM&R specialists (41%). Two additional findings pointed to deficiencies in sarcopenia knowledge and practice: participants substantially overestimated the prevalence of sarcopenia in older adults (44% of participants reported an expected prevalence of >25%) compared to findings from published studies (indicating 10% of older adults experience sarcopenia); over 75% reported not typically using specific diagnostic criteria or being unsure if their approach utilized any specific criteria. When asked what terminology they use in a medical chart for a patient presenting with significant loss of muscle mass and strength, only 8% said sarcopenia.
Conclusions
Sarcopenia, a condition that can have a major impact on older adults as they age, has not been fully incorporated into the knowledge base and practices of active physicians. The survey data suggest that improving physician familiarity with sarcopenia and having universal agreement on criteria for diagnosis may increase the screening for and treatment of sarcopenia.
Weakness is common and contributes to disability, but no consensus exists regarding a strength cutpoint to identify persons at high risk. This analysis, conducted as part of the Foundation for the ...National Institutes of Health Sarcopenia Project, sought to identify cutpoints that distinguish weakness associated with mobility impairment, defined as gait speed less than 0.8 m/s.
In pooled cross-sectional data (9,897 men and 10,950 women), Classification and Regression Tree analysis was used to derive cutpoints for grip strength associated with mobility impairment.
In men, a grip strength of 26-32 kg was classified as "intermediate" and less than 26 kg as "weak"; 11% of men were intermediate and 5% were weak. Compared with men with normal strength, odds ratios for mobility impairment were 3.63 (95% CI: 3.01-4.38) and 7.62 (95% CI 6.13-9.49), respectively. In women, a grip strength of 16-20 kg was classified as "intermediate" and less than 16 kg as "weak"; 25% of women were intermediate and 18% were weak. Compared with women with normal strength, odds ratios for mobility impairment were 2.44 (95% CI 2.20-2.71) and 4.42 (95% CI 3.94-4.97), respectively. Weakness based on these cutpoints was associated with mobility impairment across subgroups based on age, body mass index, height, and disease status. Notably, in women, grip strength divided by body mass index provided better fit relative to grip strength alone, but fit was not sufficiently improved to merit different measures by gender and use of a more complex measure.
Cutpoints for weakness derived from this large, diverse sample of older adults may be useful to identify populations who may benefit from interventions to improve muscle strength and function.
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