Reduced hip bone mineral density is related to physical fitness and leg lean mass in ambulatory individuals with chronic stroke

Association between segmental body composition and bone mineral density in US adults: results from the NHANES (2011-2018)

OBJECTIVE

The association between segmental body composition and bone mineral density (BMD) remains uncertain. The primary aim of this cross-sectional investigation was to elucidate the connection between segmental body composition and BMD within the United States adult population.

METHODS

We selected a cohort of 10,096 individuals from the National Health and Nutrition Examination Survey (NHANES) database, with a mean age of 39 years and a mean BMI of 28.5 kg/m². The parameter of segmental body composition was achieved by quantifying body fat and lean mass percentages across various anatomical regions, including the torso, Android, Gynoid, arms and legs. We conducted a weighted multivariate linear regression analysis to investigate the association between segmental body composition and total BMD. Additionally, subgroup analysis was performed based on age and gender.

RESULTS

We found an inverse association between fat proportion in each anatomical region and total BMD, with the arm and leg regions demonstrating the most significant negative correlation. Conversely, a positive correlation was observed between lean mass and BMD across all anatomical regions. These associations remained consistent in subgroup analyses.

CONCLUSION

Our investigation revealed a negative association between adipose levels in various anatomical regions and BMD among Americans aged 20 to 59. Importantly, higher fat proportion in the extremities exerted the most deleterious impact on BMD. Furthermore, an increase in lean mass within each anatomical region was ascertained to confer a positive effect on bone health. Consequently, the evaluation of segmental body composition is well-positioned to predict bone health status.

New-onset stroke on the risk of hip fracture: the Kailuan cohort study in China

PURPOSE

Stroke is a documented risk factor for hip fracture(HF). However, no data is currently available on this issue in mainland China, we therefore assessed the risk of hip fracture after new-onset stroke using a cohort study.

METHODS

This study included 165,670 participants without a history of stroke at baseline from the Kailuan study. All participants were followed biennially until December 31, 2021. During follow-up, a total of 8,496 new-onset stroke cases were identified. For each case subject, four control subjects was randomly selected, matched for age (± 1 years) and sex. The final analysis comprised 42,455 pair-matched cases and controls. A multivariate Cox proportional hazard regression model was used to estimate the effect of new-onset stroke on the risk of hip fracture.

RESULTS

During an average follow-up of 8.87 (3.94) years, a total of 231 hip fracture cases occurred, 78 cases in the stroke group and 153 cases in the control group, with incidence rates of 1.12 and 0.50 per 1000 person-years, respectively. The cumulative incidence of the stroke group was higher than that of the controls (P < 0.01). The adjusted hazard ratio (95% confidence interval) of hip fractures in the stroke group was 2.35 (1.77 to 3.12) (P < 0.001) to controls. After stratifying by gender, age, and body mass index, the higher risk was revealed in female (HR 3.10, 95 CI: 2.18 to 6.14, P < 0.001), age < 60 years old (HR 4.12, 95% CI: 2.18 to 7.78, P < 0.001), and non-obesity (BMI<28 kg/m²) (HR 1.74, 95% CI:1.31 to 2.31, P < 0.001) subgroup.

CONCLUSIONS

Stroke significantly increases the risk of hip fracture, strategy for protecting stroke patients from falls and hip fractures should be emphasized in poststroke long-term management, particularly the female, age < 60 years old, and non-obese patients.

Assessment of changes in muscle mass, strength, and quality and activities of daily living in elderly stroke patients

Whether poststroke rehabilitation improves muscle mass and quality along with the recovery of muscle strength is not clear. In this study, we examined the changes in muscle strength, muscle mass, and muscle quality in patients undergoing poststroke rehabilitation and assessed the relationship of these variables with improvement in activities of daily living (ADL). This prospective study was conducted at stroke rehabilitation unit in Japan. Muscle mass and quality were assessed using bioelectrical impedance analysis (BIA). ADLs were assessed using the functional independence measure (FIM). Grip strength of the nonaffected and affected sides was measured using hand dynamometer. All measurements were performed at admission to the stroke rehabilitation unit and at 4 weeks thereafter. We assessed changes in motor FIM items and examined the relationships among the measured variables. This study included 179 patients. Patients received stroke rehabilitation 7 days a week individually. Muscle strength and quality significantly increased after 4 weeks on both the sides. Muscle mass decreased after 4 weeks; however, there was no significant difference between the two time points. Changes in muscle strength and quality showed a significant correlation with improvement in ADLs [r = 0.66 (male), 0.45 (female) and 0.55 (male), 0.31 (female), respectively]; however, muscle mass showed no correlation with improvement in ADLs. Poststroke rehabilitation improves muscle strength and quality, as well as ADLs. Muscle mass is not an appropriate measure to assess the effects of stroke rehabilitation; it is desirable to instead use muscle strength and quality to assess stroke rehabilitation.

Convergent Validity and Test-Retest Reliability of Multimodal Ultrasonography and Related Clinical Measures in People With Chronic Stroke

OBJECTIVE

To assess the test-retest reliability of diagnostic ultrasonography measurements of the bilateral biceps brachii (BB), brachial artery, medial gastrocnemius (MG), and popliteal artery in survivors of stroke and their convergent validity with related clinical comparators.

DESIGN

Cross-sectional study.

SETTING

All procedures were conducted in a university laboratory.

PARTICIPANTS

Sixty-five community dwelling adults (N=65; 26 women, 39 men) with an average age of 60.9±7.7 years and stroke duration of 5.7±3.9 years participated in this study.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Measures of muscle structure (ie, thickness, cross-sectional area, fascicle length, pennation angle), stiffness, and intramuscular blood perfusion were conducted using B-mode, elastography and color flow Doppler ultrasonography modes, respectively. Convergent validity was assessed by examining correlations between ultrasonography measures and assessments of related constructs (ie, dynamic stiffness, isometric peak torque, spasticity, and systemic vascular function using myotonometry, dynamometry, the Composite Spasticity Scale, and the Ankle-Brachial Index, respectively). A 2-way random-effects intraclass correlation coefficient (ICC) model (ICC_2,3) was used to determine agreement between intersession measures among a smaller cohort of participants with stroke (n=20).

RESULTS

ICC estimates ranged from moderate to excellent for muscle stiffness (paretic: ICC=0.74-0.89; nonparetic: ICC=0.66-0.88), structure (paretic: ICC=0.87-0.99; nonparetic: ICC=0.81-0.98), and blood perfusion measures (paretic: ICC=0.74-0.84; nonparetic: ICC=0.73-0.88). Weak to moderate associations were found between myotonometry and elastography measures of the bilateral BB (r=0.29-0.52, P≤.05) and MG muscles (r=0.31-0.69, P≤.05). The correlations between elastography measures and spasticity scores for the paretic upper (r=0.35-0.63, P≤.05) and lower limbs (r=0.25-0.37, P≤.05) were also weak to moderate.

CONCLUSIONS

Elastography demonstrated mostly weak to moderate correlation with measures of stiffness using myotonometry as well as scores of paretic upper and lower limb spasticity. The results also indicate acceptable intersession reliability for muscle and vascular measures using several ultrasonography modalities among individuals with chronic stroke.

Relationship between bone strength index of the hemiparetic tibial diaphysis and muscle strength in people with chronic stroke: influence of muscle contraction type and speed

This study was conducted to examine the association between the tibial bone strength index and leg muscle strength of different contraction types and speeds among people with chronic stroke. We found that concentric muscle power at moderate speed was more associated with tibial bone strength index than other types.

INTRODUCTION

To compare the influence of muscle strength of different contraction types and speeds on the bone strength index of tibial diaphysis in people with chronic stroke.

METHODS

Eighty individuals with chronic stroke (age: 62.6 ± 8.0 years; men/women: 46/34; post-stroke duration: 9.0 ± 5.4 years) underwent scanning of the tibia at the 66% site on both sides using peripheral quantitative computed tomography. Each participant was also evaluated for isometric and dynamic (at 60°/s and 120°/s) strength of knee flexors/extensors and ankle dorsiflexors/plantarflexors using an isokinetic dynamometer. For a given contraction type and speed, the strength values of the four muscle groups were summed to yield a composite score. Multiple regression analysis was used to identify the association of the percent side-to-side difference (%SSD) in tibial polar-stress-strain index (p-SSI) with %SSD in muscle strength of different contraction types and speeds.

RESULTS

The p-SSI and all muscle strength parameters on the paretic side had lower values than the non-paretic side (p ≤ 0.001). The %SSD in concentric muscle power at angular speed of 60°/s (R² = 0.317, p = 0.006) and 120°/s (R² = 0.298, p = 0.020) remained independently associated with that in p-SSI, after controlling for age, sex, body mass index, post-stroke duration, motor impairment, spasticity, and physical activity level. The effect of isometric strength and eccentric muscle power was not significant in multivariate analysis.

CONCLUSIONS

Concentric muscle power was more predictive of %SSD in p-SSI at the tibial diaphysis than other contraction types and may be an important target for intervention to promote bone health in people with chronic stroke.

Measuring and Monitoring Skeletal Muscle Mass after Stroke: A Review of Current Methods and Clinical Applications

OBJECTIVES

Muscle mass at admission is important to survive stroke, and stroke-induced sarcopenia is a serious problem because of its poor prognosis. Muscle mass measurement and monitoring are essential for appropriate rehabilitation and nutrition management. However, few reviews are available about the muscle mass measurement and monitoring after stroke.

MATERIAL AND METHODS

Several methods are used to assess skeletal muscle mass in stroke, such as computed tomography (CT), ultrasound, bioelectrical impedance analysis, dual-energy X-ray absorptiometry, biomarkers, and anthropometrics. We summarized the current methods and clinical applications in stroke.

RESULTS

In stroke, a head CT is used to estimate muscle mass by measuring the temporal muscle. However, it can be conducted retrospectively due to radiation exposure. After stroke, limb muscle atrophy and diaphragm dysfunction are observed using ultrasound. However, ultrasound requires an understanding of the methods and skill. A bioelectrical impedance analysis can be used to assess muscle mass in patients after a stroke unless they have dynamic fluid changes. Dual-energy X-ray absorptiometry is used for follow-up after hospital discharge. Urinary titin N-fragment and serum C-terminal agrin fragment reflect muscle atrophy after stroke. Anthropometrics may be useful with limited resources.

CONCLUSIONS

We summarized the features of each measurement and proved the recent evidence to properly measure and monitor skeletal muscle mass after stroke.

Determinants of estimated failure load in the distal radius after stroke: An HR-pQCT study

Bone health is often compromised after stroke and the distal radius is a common site of fragility fractures. The macro- and mircoproperties of bone tissue after stroke and their clinical correlates are understudied. The objectives of the study were to use High-Resolution peripheral Quantitative Computed Tomography (HR-pQCT) to investigate the bone properties at the distal radius, and to identify the correlates of estimated failure load for the distal radius in people with chronic stroke. This was a cross-sectional study of 64 people with stroke (age: 60.8 ± 7.7 years, stroke duration: 5.7 ± 3.9 years) and 64 age- and sex-matched controls. Bilateral bone structural, densitometric, geometric and strength parameters of the distal radius were measured using HR-pQCT. The architecture, stiffness and echo intensity of the bilateral biceps brachii muscle and brachial artery blood flow were evaluated using diagnostic ultrasound. Other outcomes included the Fugl-Meyer Motor Assessment (FMA), Motor Activity Log (MAL), and Composite Spasticity Scale (CSS). The results revealed a significant side (paretic vs non-paretic for the stroke group, non-dominant vs dominant for controls) by group (stroke vs control) interaction effect for estimated failure load, cortical area, cortical thickness, trabecular number and trabecular separation, and all volumetric density parameters. Post-hoc analysis showed percent side-to-side differences in bone outcomes were greater in the stroke group than the control group, with the exception of trabecular thickness and intracortical porosity. Among the HR-pQCT variables, percent side-to-side difference in trabecular volumetric bone mineral density contributed the most to the percent side-to-side difference in estimated failure load in the stroke group (R² change = 0.334, β = 1.106). Stroke-related impairments (FMA, MAL, CSS) were found to be significant determinants of the percent side-to-side difference in estimated failure load (R² change = 0.233, β = -0.480). This was the first study to examine bone microstructure post-stroke. We found that the paretic distal radius had compromised bone structural properties and lower estimated failure load compared to the non-paretic side. Motor impairment was a determinant of estimated bone strength at the distal radius and may be a potential intervention target for improving bone health post-stroke.

Effects of different vibration frequencies on muscle strength, bone turnover and walking endurance in chronic stroke

This randomized controlled trial aimed to evaluate the effects of different whole body vibration (WBV) frequencies on concentric and eccentric leg muscle strength, bone turnover and walking endurance after stroke. The study involved eighty-four individuals with chronic stroke (mean age = 59.7 years, SD = 6.5) with mild to moderate motor impairment (Fugl-Meyer Assessment lower limb motor score: mean = 24.0, SD = 3.5) randomly assigned to either a 20 Hz or 30 Hz WBV intervention program. Both programs involved 3 training sessions per week for 8 weeks. Isokinetic knee concentric and eccentric extension strength, serum level of cross-linked N-telopeptides of type I collagen (NTx), and walking endurance (6-min walk test; 6MWT) were assessed at baseline and post-intervention. An intention-to-treat analysis revealed a significant time effect for all muscle strength outcomes and NTx, but not for 6MWT. The time-by-group interaction was only significant for the paretic eccentric knee extensor work, with a medium effect size (0.44; 95% CI: 0.01, 0.87). Both WBV protocols were effective in improving leg muscle strength and reducing bone resorption. Comparatively greater improvement in paretic eccentric leg strength was observed for the 30 Hz protocol.

Preventive Effects of Repetitive Peripheral Magnetic Stimulation on Muscle Atrophy in the Paretic Lower Limb of Acute Stroke Patients: A Pilot Study

Objective:

The aim of this study was to investigate the effect of repetitive peripheral magnetic stimulation (rPMS) on muscle atrophy prevention in the rectus femoris muscle (RF) of the paretic limb in acute stroke patients.

Methods:

Twelve acute stroke patients with a National Institute of Health Stroke Scale score >5 and a motor score of the paretic lower limb >2 at admission were divided into an intervention group (rPMS: mean age, 75±6.4 years) and a conventional care group (non-rPMS: mean age, 62±11.8 years). Baseline measurements were performed within 4 days of stroke onset. In the rPMS group, treatment was applied to the paretic thigh only for 2 weeks, 5 days a week, in addition to conventional care. The cross-sectional area (CSA) of the RF was assessed in both limbs using ultrasound at baseline and 2 weeks later. Data on patient characteristics were collected from the clinical records to assess correlations with the CSA rate of change.

Results:

Patients in the rPMS group were significantly older. Although the CSA of the RF did not change significantly on either side in the rPMS group, there was a significant decrease in the CSA on the paretic side in the non-rPMS group. However, no significant difference was observed in the CSA rate of change in the rPMS and non-rPMS groups. The CSA rate of change on the paretic side correlated negatively with age in the rPMS group.

Conclusions:

Our results suggest that rPMS prevents muscle atrophy more effectively in patients in their 60s than in patients more than 70 years old.

Correlation of Body Composition and Nutritional Status with Functional Recovery in Stroke Rehabilitation Patients

Previous studies have suggested that the nutritional status after stroke is independently associated with long-term outcomes and that sarcopenia delays poststroke rehabilitation and worsens the prognosis. However, many stroke patients have a deteriorated nutritional status and a decreased muscle mass in the acute phase. This prospective study included 179 patients who were admitted to the stroke rehabilitation unit. We performed bioelectrical impedance analysis and determined the Geriatric Nutritional Risk Index (GNRI) to assess muscle mass and the nutritional status on admission. Furthermore, we analyzed the activities of daily living using the Functional Independence Measure (FIM) at the time of admission and four weeks later. Furthermore, we evaluated the change in motor FIM items and examined the relationship with the data. Multiple regression analysis revealed that a high muscle rate (skeletal muscle mass/body weight) (odds ratio OR = 2.43), high phase angle (OR = 3.32), and high GNRI (OR = 2.57) were significantly associated with motor FIM items at four weeks in male and female patients. Muscle mass maintenance through nutritional management and early rehabilitation in the acute period of stroke is essential for functional recovery in stroke patients.

Drug treatment strategies for osteoporosis in stroke patients

INTRODUCTION

Osteoporosis and subsequent fractures are well-recognized complications of stroke. However, drug treatment strategies for osteoporosis after stroke have been rarely discussed in the current guidelines for the management of stroke or osteoporosis.

AREAS COVERED

The authors review the epidemiology, characteristics, pathophysiology, and risk prediction of post-stroke osteoporosis and fractures. Then they provide an overview of existing evidence regarding drug treatment strategies for osteoporosis in stroke patients. They also review the effects on bone mineral density (BMD) and fractures for those drugs commonly used in stroke patients.

EXPERT OPINION

Currently, there is scarce evidence. A small randomized control trial suggested that a single use of 4 mg of intravenous zoledronate within 5 weeks of stroke onset was beneficial for preserving BMD, while simultaneous use of calcium and vitamin D supplements may be effective in preventing hypocalcemia. Further studies are needed to address several important issues of post-stroke osteoporosis, including who (the eligibility for treatment), when (the best timing of treatment), what (which drug), and how long (the best duration of treatment). On the other hand, physicians should bear in mind that drugs commonly used for stroke, such as statins or warfarin, may have beneficial or adverse effects on BMD and fracture risks.

The impact of stroke on bone properties and muscle-bone relationship: a systematic review and meta-analysis

To systematically review available evidence related to the characteristics of bone changes post-stroke and the relationship between various aspects of muscle function (e.g., strength, spasticity) and bone properties after stroke onset. An extensive online database search was undertaken (last search in January 2019). Articles that examined the bone properties in stroke patients were included. The quality of the studies was evaluated with the National Institutes of Health (NIH) Study Quality Assessment Tools. Publication bias of meta-analyses was assessed using the Egger's regression asymmetry test. The selection and evaluation of the articles were conducted by two independent researchers. Fifty-nine studies were identified. In subacute and chronic stroke studies, the skeletal sites in the paretic limbs sustained a more pronounced decline in bone quality than did their counterparts in the non-paretic limbs. The rate of changes showed a decelerating trend as post-stroke duration increased, but the timing of achieving the steady rate differed across skeletal sites. The magnitude of bone changes in the paretic upper limb was more pronounced than the paretic lower limb. There was a strong relationship between muscle strength/mass and bone density/strength index. Muscle spasticity seemed to have a negative impact on bone integrity in the paretic upper limb, but its influence on bone properties in the paretic lower limb was uncertain. Substantial bone changes in the paretic limbs occurred particularly in the first few months after stroke onset. Early intervention, muscle strength training, and long-term management strategies may be important to enhance bone health post-stroke. This review has also revealed the knowledge gaps which should be addressed in future research.

The regularity of orthosis use and the reasons for disuse in stroke patients

This is a Retrospective descriptive study. Orthoses and walking aids are used frequently in stroke rehabilitation to facilitate ambulation. The aim was to describe the regularity of orthosis use and the reasons for disuse in stroke after discharge from inpatient rehabilitation. The study included 64 (43 men, 21 women) subacute stroke patients who had been discharged from our clinic in the last 6 months. Demographic and clinical findings, proposed orthoses and walking aids, frequency of usage for the proposed orthoses, reasons for disuse, and the ambulation levels were recorded. A total of 54 (84.4%) patients had an ankle-foot orthosis and 10 (15.6%) patients had a knee-ankle-foot orthosis. The orthosis frequency of use was every day in 38 (59.4%) patients and one to seven times a week in seven (10.9%) patients, whereas 19 (29.7%) did not use them. The reasons for orthosis disuse were finding them unnecessary in seven (27%) patients, usage difficulties in six (23%) patients, pressure sensation in five (19.2%) patients, the belief that they did not make life easier in five (19.2%) patients, lack of a suitable environment in one (3.8%) patient, orthosis wear in one (3.8%) patient, and systemic disease in one (3.8%) patient. Age, sex, residence, the disease duration, and recommended orthosis duration (how long the prescribed orthosis was used), recommended orthosis, range of motion limitation in the lower extremities, presence of spasticity, type of orthosis, and the ambulation level were not statistically significantly associated with the frequency of orthosis use (P>0.05). The only significant clinical factor for the frequency of orthosis use was the lower extremity Brunnstrom neurophysiological recovery stage (P<0.008). Orthosis use had been discontinued by 29% of the patients. The most common reasons reported for discontinuing orthosis use were that the patients found it unnecessary, usage difficulty, pressure sensation, not making life easier, lack of a suitable environment, and orthosis wear. The only significant clinical factor for the frequency of orthosis use was the lower extremity Brunnstrom neurophysiological recovery stage.

Parkinson's disease and risk of hip fracture: systematic review and meta-analysis

The relationship between Parkinson's disease (PD) and risk of hip fracture yielded inconsistent results. Therefore, we conducted the present systematic review and meta-analysis of published observational studies to assess the association between PD and risk of hip fracture. PubMed, ISI, EMBASE, and Cochrane databases were searched systematically to identify studies assessing the relationship between PD and the risk of hip fracture up to July 01, 2017. In addition, to find related articles, the reference section of retrieved articles was checked. Random-effects model was used for calculation of pooled hazard ratio (HR) and 95% confidence intervals (CI). Thirteen independent studies containing 564,947 participants were included in the meta-analysis. The overall results of included studies showed PD to be associated with the risk of hip fracture (HR_overall = 3.13, 95% CI 2.53-3.87) in women 3.11 (2.51-3.86) and men 2.60 (2.19-3.09). Our meta-analysis showed the direct association between PD and the risk of hip fracture in both men and women. However, due to the limitations of this study, further well-designed studies are required to confirm our findings.

Dual energy X-ray absorptiometry body composition reference values of limbs and trunk from NHANES 1999-2004 with additional visualization methods

Body Mass Index has traditionally been used as a measure of health, but Fat Mass Index (FMI) and Lean Mass Index (LMI) have been shown to be more predictive of mortality and health risk. Total body FMI and LMI reference curves have particularly been useful in quantifying sarcopenia and sarcopenic obesity. Research has shown regional composition has significant associations to health outcomes. We derived FMI and LMI reference curves of the regions of the body (leg, arm, and trunk) for 15,908 individuals in the 1999-2004 National Health and Nutrition Examination Survey data for each sex and ethnicity using the Lambda-Mu-Sigma (LMS) method and developed software to visualize this regional composition. These reference curves displayed differentiation between males and females during puberty and sharper limb LMI declines during late adulthood for males. For adults ages 30-50, females had 39%, 83%, and 47% larger arm, leg, and trunk FMI values than males, respectively. Males had 49%, 20%, and 15% higher regional LMI values than females for the arms, legs, and trunk respectively. The leg FMI and LMI of black females were 14% and 15% higher respectively than those of Hispanic and white females. White and Hispanic males had 37% higher trunk FMI values than black males. Hispanic females had 20% higher trunk FMI than white and black females. These data underscore the importance of accounting for sex and ethnicity in studies of regional composition. This study is the first to produce regional LMI and FMI reference tables and curves from the NHANES dataset. These reference curves provide a framework useful in studies and research involving sarcopenia, obesity, sarcopenic obesity, and other studies of compositional phenotypes. Further, the software tool we provide for visualizing regional composition will prove useful in monitoring progress in physical therapy, diets, or other attempts to attain healthier compositions.

Skeletal muscle changes following stroke: a systematic review and comparison to healthy individuals

BACKGROUND

Despite extensive study of the impact of stroke on muscle and functional performance, questions remain regarding the extent to which changes are due to the neurological injury vs. age-related loss of morphology and force production.

OBJECTIVES

To synthesize available evidence describing post-stroke changes in lower extremity muscle size and strength compared to healthy adults.

METHODS

Scientific literature was searched up to April 2016 to identify studies that included lower extremity muscle size and strength measures in individuals with chronic stroke. Lower extremity muscle size and strength data from healthy controls were sought for comparison. Relative differences were calculated between paretic, nonparetic, and control limbs.

RESULTS

Fifteen studies with 375 participants (61% male; age = 62 ± 5 years; time since stroke = 60 ± 42 months) were included. The paretic limb exhibited deficits of ~13% in thigh muscle size, ~5% in lower leg muscle size, and ~8% in lean leg mass compared to the nonparetic limb. Paretic plantarflexor and knee extensor strength were 52 and 36% lower, respectively, compared to the nonparetic limb. When compared to age-matched control data, both paretic and nonparetic limbs showed deficits in muscle size and strength.

CONCLUSIONS

Age-related differences support the impact of stroke-related sarcopenia as a contributor to hemiparetic muscle dysfunction. Understanding these muscular changes is necessary for designing appropriate exercise interventions aimed at restoring muscle function.

Sex differences in the association between stroke and bone mineral density in elderly Koreans: The Korean National Health and Nutrition Examination Survey, 2008-2010

OBJECTIVES

The aim of this study was to investigate whether osteoporosis is more prevalent in elderly Korean people who have had a stroke and whether the association differs by sex.

STUDY DESIGN

A total of 3806 elderly subjects (1951 men and 1855 women) from the Korea National Health and Nutrition Examination Survey were included in this study. Stroke history was determined by self-administered questionnaire. Bone mineral density (BMD) was measured at the lumbar spine, total hip, and neck of the femur using dual-energy X-ray absorptiometry. It was categorized as normal, osteopenia, or osteoporosis.

RESULTS

In men who had had a stroke, the prevalence of osteoporosis was greater than that of both osteopenia and normal BMD, and the prevalence of osteopenia was greater than that of normal BMD (p<0.001). However, there were no significant differences in BMD level among women who had had a stroke. Men who had had a stroke undertook less vigorous exercise and moderate-or-vigorous exercise than did men who had not had a stroke (p=0.002 and 0.030, respectively). After adjusting for all covariates, the mean BMD at the lumbar spine, total hip and neck of the femur was lower in men who had had a stroke than in men who had not (p=0.034, 0.002, and 0.005, respectively). There were no significant differences in mean BMD at any of the three sites between women who had and women who had not had a stroke.

CONCLUSION

Men who have had a stroke have a higher prevalence of osteopenia and osteoporosis, and have lower BMD at the total hip and femur neck than men who have not had a stroke.

Guidelines for Adult Stroke Rehabilitation and Recovery: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

PURPOSE

The aim of this guideline is to provide a synopsis of best clinical practices in the rehabilitative care of adults recovering from stroke.

METHODS

Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association (AHA) Stroke Council's Scientific Statement Oversight Committee and the AHA's Manuscript Oversight Committee. The panel reviewed relevant articles on adults using computerized searches of the medical literature through 2014. The evidence is organized within the context of the AHA framework and is classified according to the joint AHA/American College of Cardiology and supplementary AHA methods of classifying the level of certainty and the class and level of evidence. The document underwent extensive AHA internal and external peer review, Stroke Council Leadership review, and Scientific Statements Oversight Committee review before consideration and approval by the AHA Science Advisory and Coordinating Committee.

RESULTS

Stroke rehabilitation requires a sustained and coordinated effort from a large team, including the patient and his or her goals, family and friends, other caregivers (eg, personal care attendants), physicians, nurses, physical and occupational therapists, speech-language pathologists, recreation therapists, psychologists, nutritionists, social workers, and others. Communication and coordination among these team members are paramount in maximizing the effectiveness and efficiency of rehabilitation and underlie this entire guideline. Without communication and coordination, isolated efforts to rehabilitate the stroke survivor are unlikely to achieve their full potential.

CONCLUSIONS

As systems of care evolve in response to healthcare reform efforts, postacute care and rehabilitation are often considered a costly area of care to be trimmed but without recognition of their clinical impact and ability to reduce the risk of downstream medical morbidity resulting from immobility, depression, loss of autonomy, and reduced functional independence. The provision of comprehensive rehabilitation programs with adequate resources, dose, and duration is an essential aspect of stroke care and should be a priority in these redesign efforts. (Stroke.2016;47:e98-e169. DOI: 10.1161/STR.0000000000000098.).

Muscle RANK is a key regulator of Ca2+ storage, SERCA activity, and function of fast-twitch skeletal muscles

Receptor-activator of nuclear factor-κB (RANK), its ligand RANKL, and the soluble decoy receptor osteoprotegerin are the key regulators of osteoclast differentiation and bone remodeling. Here we show that RANK is also expressed in fully differentiated myotubes and skeletal muscle. Muscle RANK deletion has inotropic effects in denervated, but not in sham, extensor digitorum longus (EDL) muscles preventing the loss of maximum specific force while promoting muscle atrophy, fatigability, and increased proportion of fast-twitch fibers. In denervated EDL muscles, RANK deletion markedly increased stromal interaction molecule 1 content, a Ca(2+)sensor, and altered activity of the sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) modulating Ca(2+)storage. Muscle RANK deletion had no significant effects on the sham or denervated slow-twitch soleus muscles. These data identify a novel role for RANK as a key regulator of Ca(2+)storage and SERCA activity, ultimately affecting denervated skeletal muscle function.

Prevalence of and risk factors for osteoporosis in adults with acquired brain injury

BACKGROUND

Low bone mineral density (BMD) is common in older people with stroke, particularly in the paretic limb. Younger people with acquired brain injury (ABI), of all causes, are at increased risk of low BMD.

AIMS

To examine prevalence of low BMD, based on World Health Organisation diagnostic criteria, in patients with ABI.

METHODS

This is a cross-sectional study of 112 ABI patients. All completed a questionnaire, had laboratory investigations and DXA assessment of lumbar spine and one or both hips.

RESULTS

Mean age ± SD of participants was 45.7 ± 13.7 years. Risk of vitamin D deficiency (25-OHD < 30 nmol/L) occurred in 27.7 %, 34.3 % had adequate levels (30-50 nmol/L) and 36.6 % had levels in excess of this. Based on T-scores, 41.1 % had osteopenia and 21.4 % had osteoporosis. A Z score of -1 or less but greater than -2 occurred in 25 %; a further 21.4 % had a Z score of -2 or less. Patients who could walk outdoors had significantly higher BMD at the neck of femur than those who walked indoors only and those who could not walk at all (p < 0.001). On multiple linear regression analysis, ambulatory ability and duration of disability were independent predictors of BMD at sound neck of femur and total proximal femur.

CONCLUSIONS

Osteopenia and osteoporosis are common in young adults with ABI compared with the general population. Bone heath monitoring should form part of the long-term follow-up of this patient group.

Unaffected arm muscle hypercatabolism in dysphagic subacute stroke patients: the effects of essential amino acid supplementation

Alterations in muscle protein turnover of the unaffected side of stroke patients could contribute to physical disability. We investigated whether hypercatabolic activity occurred in unaffected arm muscle and whether supplemented essential amino acids (EAAs) could limit muscle hypercatabolism (MH). Thirty-eight dysphagic subacute stroke subjects (<3 months after acute event) (29 males+9 females; 69.7±11.4 yrs) were enrolled and randomized to receive 8 g/day EAAs (n=19; EAA group) or isocaloric placebo (maltodextrin; n=19, Plac group). Before randomization, all patients had their arterial (A) and venous (V) amino acids measured and muscle (A-V) differences calculated in the unaffected arm. Eight matched and healthy subjects served as controls. When compared to healthy controls, the entire stroke population showed significant muscle release (=negative value A-V) of the amino acid phenylalanine (phenyl-) indicating a prevalence of MH. Moreover, randomized EAA and Plac groups had similar rates of MH. After 38 days from the start of the protocol, the EAA group but not the Plac group had MH converted to balanced protein turnover or anabolic activity. We concluded that muscle protein metabolism of the unaffected arm of dysphagic subacute stroke individuals could be characterized by MH which can be corrected by supplemented EAAs.

Predictors of low bone mineral density of the stroke-affected hip among ambulatory individuals with chronic stroke

Risk of hip fracture is greater poststroke than in an age-matched healthy population, in part because of declining hip BMD. We found that individuals may be at risk of loss of hip BMD from muscle atrophy, asymmetrical gait, and poor affected-side ankle dorsiflexor strength. These impairments may be targeted during rehabilitation.

INTRODUCTION

This study aimed to determine predictors of low hip BMD on the stroke-affected side in people living in the community.

METHODS

Forty-three participants (female; 27.9%), mean age 62.4 ± 13.5 and 17.9 ± 32.8 months, poststroke with motor impairments underwent dual energy X-ray absorptiometry scans. Gait characteristics, isometric strength, body composition, and fasting plasma lipids were measured.

RESULTS

At entry, 34.9% (15/43) of the participants had low total hip BMD on the stroke-affected side. Of those with low BMD, 93.3% (14/15) had a step length symmetry ratio >1, indicating greater reliance on the non-paretic leg for weight bearing. Logistic regression analysis revealed that lower affected-side ankle dorsiflexor strength (ß = 0.700, p = 0.02), lower total body fat-free mass index (ß = 0.437, p = 0.02), and greater step length symmetry ratio during walking (ß = 1.135 × 10(3), p = 0.03) were predictors of low hip BMD.

CONCLUSION

Low BMD of the stroke-affected side hip is prevalent in over a third of individuals with lower limb motor impairments. These individuals may be at particular risk of accelerated loss of BMD at the hip from asymmetrical gait pattern and poor affected-side ankle dorsiflexor strength. These impairments are intervention targets that may be addressed during rehabilitation which includes resistance training and addresses gait impairments.

Changes in the Range of Motion of the Hip Joint and the Muscle Activity of the Rectus Femoris and Biceps Femoris of Stroke Patients during Obstacles Crossing on the Ground and Underwater

[Purpose] The purpose of this study was to examine range of motion (ROM) and the muscle activity of stroke patients during obstacle task on the ground and underwater. [Subjects] The subjects of this study were seven stroke patients in a hospital located in Daejeon, South Korea. [Methods] The measurements in this study were conducted in an exercise therapy room and a pool dedicated to underwater exercise (water temperature 33.5 °C, air temperature 27 °C) in the hospital building. The pool’s water depth was determined by considering the levels of the xiphoid process of the study subjects. Ten-centimeter-high obstacles were used. An electrogoniometer was used to examine the ROM of flexion and extension of the hip joints on the affected side. An MP150 system a BioNomadix 2-channel wireless EMG transmitter was used to examine the muscle activity of the rectus femoris and biceps femoris of the affected side. [Conclusion] The results suggest that the unaffected side was supported, that the affected side moved, and that the hip joint was bent more underwater than on the ground. The rectus femoris and bicpes femoris were activated significantly less underwater than on the ground in all sections.

Impact of Adapted Physical Activity and Therapeutic Patient Education on Functioning and Quality of Life in Patients With Postacute Strokes

Objective. The aim of this study was to assess whether the combination of Adapted Physical Activity (APA) and Therapeutic Patient Education (TPE) improves function and quality of life in survivors of strokes. Methods. This nonrandomized controlled study enrolled patients with mild to moderate hemiparesis referred to 2 physical medicine and rehabilitation units in Emilia-Romagna, Italy, 3 to 18 months after a single unilateral mild to moderate stroke. The experimental group (n = 126) received 16 APA sessions and 3 sessions of TPE, and the control group (n = 103) received usual care; 86.9% completed treatment. The main outcome measure was a 4-month change in gait endurance (that corresponds to 2 months after intervention in the experimental group), and secondary outcomes included the Short Physical Performance Battery, Berg Balance Scale, Barthel Index, Geriatric Depression Scale, 12-item Short-Form Health Survey, and Caregiver Strain Index. Changes in scores at 4 months were compared between groups using analysis of variance and controlling for group imbalance by means of the propensity score. Results. Gait endurance, physical performance, balance, and the physical component of the quality of life score increased significantly at 4 months in the APA group and remained stable in the control group. The propensity-adjusted between-group change was significant for these scores at P < .01. Conclusions. Our results confirm that it is feasible and potentially effective to implement APA programs for elderly patients with complex clinical conditions as early as 3 months after a stroke and suggest that, when combined with TPE, the effects of a postrehabilitation APA program are relatively enduring.

A cross-sectional study of loss of muscle mass corresponding to sarcopenia in healthy Chinese men and women: reference values, prevalence, and association with bone mass

A cross-sectional survey was conducted in Shanghai, eastern China, to evaluate the prevalence of loss of muscle mass corresponding to sarcopenia in Chinese men and women and compare the results with the prevalence in other populations. We also analyzed the differences between men and women, and assessed the effect of lean mass and fat mass of different regions on bone mass. A total of 1766 men and 1778 women aged 18-96 years participated in this study. Bone mineral density of spine and femur, and lean mass and fat mass of several body regions were measured by dual-energy X-ray absorptiometry. Class 1 and class 2 sarcopenia were defined as the appendicular lean mass (ALM) index (ALM/height(2)) 1 and 2 standard deviations below the sex-specific means for young adults. Mean values for ALM index were 7.93 for men and 6.04 kg/m(2) for women, aged 18-40 years. The reference values for classes 1 and 2 sarcopenia were 7.01 and 6.08 kg/m(2) in men and 5.42 and 4.79 kg/m(2) in women. The prevalence of sarcopenia was 4.8% in women and 13.2% in men aged 70 years and older, which is lower than that in Caucasian populations, but the same as that in Japanese and Koreans in Asia. Men demonstrated greater declines in muscle mass with aging than women, partly due to the protective effect of fat mass on lean mass in women. Leg lean mass was the strongest factor on femur bone mass; however, trunk lean mass was the strongest factor on spine bone mass. Maintaining a healthy weight is important for the elderly in order to avoid osteoporosis and sarcopenia.

Changes to volumetric bone mineral density and bone strength after stroke: a prospective study

RATIONALE AND AIM

Stroke survivors experience accelerated bone loss and increased fracture risk, particularly in paretic weight bearing limbs. Understanding how these changes unfold and their relationship to stroke severity and physical activity could help in the development of targeted interventions to prevent or reduce the severity of these outcomes. The primary aim of this study is to investigate the time course and magnitude of changes in volumetric bone mineral density within the first year after stroke, and to examine relationships with physical activity and motor recovery.

DESIGN

This is a prospective, observational study of 43 nondiabetic, nonambulant adults with first ever hemispheric stroke.

PRIMARY OUTCOME

The primary outcome was the difference in six-month change of total volumetric bone mineral density between paretic and nonparetic distal tibiae, measured at 7% of bone length site using high-resolution peripheral quantitative computed tomography.

SECONDARY OUTCOMES

The secondary outcomes are cortical and trabecular volumetric bone mineral density, cortical thickness, and total and cross-sectional areas of distal tibiae and radii of paretic and nonparetic limbs. Also included are total body and regional bone mineral density derived using dual-energy X-ray absorptiometry, physical activity measured using accelerometry, and motor recovery (Chedoke McMaster Stroke Assessment).

DISCUSSION

Measuring the timing and magnitude of changes to volumetric bone mineral density and bone structure from immediately after stroke, and relationships between these changes with physical activity and motor recovery will provide the basis for targeted interventions to reduce fracture risk in stroke survivors.

Relationship of body fat and its distribution with bone mineral density in Indian population

Obesity has been associated with increased bone mineral density (BMD). There is evidence of differential effect of regional fat on BMD. Hence, we undertook this study to evaluate the correlation between total body fat and its distribution with BMD in nonobese (mean body mass index: 25.0 ± 4.7 kg/m²) Indian adult volunteers. A total of 2347 participants (men: 39.4% and women: 60.6%) included in this cross-sectional study were divided according to sex and age. Fasting blood samples were drawn for biochemical parameters. Percent total body, truncal, and leg fat and BMD at lumbar spine, femur, and forearm were measured by dual-energy X-ray absorptiometry. The BMD at all sites (radius, femur, and spine) increased from lowest to highest quartiles of percent body fat. Percent truncal fat was positively correlated with BMD at all sites in both sexes, except for femoral neck in men, where it had negative correlation. Percent leg fat was positively related with BMD at all sites in premenopausal women, and spine and radius BMD in postmenopausal women. However, in men, it had negative correlation with femoral neck BMD. On multiple regression analysis, regional fat had positive association with BMD at all sites after adjusting for age, sex, lean mass index, 25-hydroxyvitamin D, and intact parathyroid hormone levels. Leg-to-total body fat ratio was negatively associated with BMD at all sites in men and pre- and postmenopausal women. Percent total body and regional fat have positive association with BMD at all sites in men and women.

Vascular elasticity and grip strength are associated with bone health of the hemiparetic radius in people with chronic stroke: implications for rehabilitation

BACKGROUND

People with stroke often have increased bone loss and fracture rate. Increasing evidence has demonstrated a link between cardiovascular health and bone loss in other patient populations.

OBJECTIVE

The study objectives were: (1) to compare the bone density and geometry of the radius diaphysis on the left and right sides in people with chronic stroke and people who were matched for age (control participants) and (2) to examine the relationship between the bone strength index at the hemiparetic radius diaphysis and vascular health in people with chronic stroke.

DESIGN

This was a case-control study.

METHODS

The radius diaphysis on both sides was scanned with peripheral quantitative computed tomography in 65 participants with chronic stroke and 34 control participants. Large-artery and small-artery elasticity indexes were evaluated with a cardiovascular profiling system.

RESULTS

The paretic radius diaphysis had significantly lower values for cortical bone mineral density, cortical thickness, cortical area, and the bone strength index but a larger marrow cavity area than the nonparetic radius diaphysis in participants with chronic stroke, whereas no bone measurement showed a significant side-to-side difference in control participants. Multiple regression analyses showed that the large-artery elasticity index and grip strength remained significantly associated with the bone strength index at the hemiparetic radius diaphysis after controlling for age, sex, time since stroke diagnosis, body mass index, and physical activity (R(2)=.790).

LIMITATIONS

This study was cross-sectional and could not establish causality. The radius diaphysis is not the most common site of fracture after stroke.

CONCLUSIONS

Both the integrity of the vasculature and muscle strength were significantly associated with the bone strength index at the hemiparetic radius diaphysis in participants with chronic stroke. The results may be useful in guiding rehabilitative programs for enhancing bone health in the paretic arm after stroke.

Changes in fat mass in stroke survivors: a systematic review

BACKGROUND

Stroke survivors have less muscle mass in their paretic limbs compared with nonparetic limbs, which may or may not be accompanied by changes in regional and/or whole body fat mass.

AIM

To examine the current evidence regarding differences in regional fat mass between paretic and nonparetic limbs and changes in whole body fat mass over time in stroke survivors.

METHODS

A systematic search of relevant databases. Studies measuring whole body or regional fat mass using dual-energy X-ray absorpiometry, computed tomography, or magnetic resonance imaging were included.

RESULTS

Eleven trials were identified. Fat mass differences between paretic and nonparetic limbs and change in fat mass over time were not consistent. Meta-analyses were conducted using dual-energy X-ray absorpiometry-derived data from 10 trials (n = 324). There were no differences in fat mass between paretic and nonparetic legs (pooled mean difference 31·4 g, 95% confidence interval -33·9 to 96·6, P = 0·35), and slightly greater fat mass in the paretic arms compared with nonparetic arms (pooled mean difference 84·0 g, 95% confidence interval 30·7 to 137·3, P = 0·002). Whole body fat mass did not increase significantly between one-month and six-months poststroke (pooled mean difference 282·3 g, 95% confidence interval -824·4 to 1389, P = 0·62), but there was an increase between six- and 12 months poststroke (pooled mean difference 1935 g, 95% confidence interval 1031 to 2839, P < 0·001).

CONCLUSIONS

There were inconsistent findings regarding changes in fat mass after stroke. Large, well-designed studies are required to further investigate the impact of body composition changes on the health of stroke survivors.

Cardiorespiratory Fitness after Stroke: A Systematic Review

Cardiorespiratory fitness programs are increasingly used in stroke rehabilitation. Maximal oxygen uptake is the gold standard measurement of cardiorespiratory fitness; however, no recent publications have collated evidence about maximal oxygen uptake levels following stroke. We therefore performed a systematic review of maximal oxygen uptake in stroke survivors, aiming to observe changes in levels over time, and associations with severity of stroke. We searched Medline and Embase until April 2011, and included cross-sectional studies, longitudinal studies, and baseline data from intervention trials. Studies had to recruit at least 10 stroke survivors, and report direct measurement of maximal/peak oxygen uptake. We then compared maximal oxygen uptake with published data from age and gender-matched controls. The search identified 3357 articles. Seventy-two full texts were retrieved, of which 41 met the inclusion criteria. Time since stroke ranged from 10 days to over seven-years. Peak oxygen uptake ranged from 8 to 22 ml/kg/min, which was 26–87% of that of healthy age- and gender-matched individuals. Stroke severity was mild in most studies. Three studies reported longitudinal changes; there was no clear evidence of change in peak oxygen uptake over time. Most studies recruited participants with mild stroke, and it is possible that cardiorespiratory fitness is even more impaired after severe stroke. Maximal oxygen uptake might have been overestimated, as less healthy and older stroke survivors may not tolerate maximal exercise testing. More studies are needed describing mechanisms of impaired cardiorespiratory fitness and longitudinal changes over time to inform the optimal ‘prescription’ of cardiorespiratory fitness programs for stroke survivors.

The risk of stroke after percutaneous vertebroplasty for osteoporosis: a population-based cohort study

Purpose

To investigate the incidence and risk of stroke after percutaneous vertebroplasty in patients with osteoporosis.

Methods

A group of 334 patients with osteoporosis, and who underwent percutaneous vertebroplasty during the study period, was compared to 1,655 age-, sex- and propensity score-matched patients who did not undergo vertebroplasty. All demographic covariates and co-morbidities were deliberately matched between the two groups to avoid selection bias. Every subject was followed-up for up to five years for stroke. Adjustments using a Cox regression model and Kaplan-Meier analyses were conducted.

Results

A total of 1,989 osteoporotic patients were followed up for 3,760.13 person-years. Overall, the incidence rates of any stroke, hemorrhagic stroke and ischemic stroke were 22.6, 4.2 and 19.6 per 1,000 person-years, respectively. Patients who underwent vertebroplasty were not more likely to have any stroke (crude hazard ratio = 1.13, p = 0.693), hemorrhagic stroke (HR = 2.21, p = 0.170), or ischemic stroke (HR = 0.96, p = 0.90). After adjusting for demographics, co-morbidities and medications, the vertebroplasty group had no significant difference with the comparison group in terms of any, hemorrhagic and ischemic strokes (adjusted HR = 1.22, 3.17, and 0.96, p = 0.518, 0.055, and 0.91, respectively).

Conclusions

Osteoporotic patients who undergo percutaneous vertebroplasty are not at higher risk of any stroke in the next five years after the procedure.

Bone health in multiple sclerosis

People who are disabled with multiple sclerosis (MS) may be at increased risk of osteoporosis. This review discusses issues relevant to bone health in MS and makes practical recommendations regarding prevention and screening for osteoporosis and fracture risk in MS. A search of the literature up until 5 April 2011 was performed using key search terms, and articles pertinent to bone health in MS were analysed. Bone mineral density (BMD) is reduced at the lumbar spine, hip and total body in MS, with the degree of reduction being greatest at the hip. A strong relationship exists between the disability level, measured by the Expanded Disability Status Score, and BMD at the lumbar spine and femoral neck, particularly the latter. The rate of loss of BMD also correlates with the level of disability. Pulsed corticosteroids for acute episodes of MS, even with a high cumulative steroid dose, do not significantly affect BMD, but an effect on fracture risk is yet to be elucidated. There appears to be no correlation between vitamin D levels and BMD, and the relationship between disability and vitamin D levels remains unclear. Falls and fractures are more common than in healthy controls, and the risk rises with increasing levels of disability. The principal factor resulting in low BMD and increased fracture risk in MS is immobility. Antiresorptive therapy with bisphosphonates and optimising vitamin D levels are likely to be effective interventions although there are no randomised studies of this therapy.

Fat content of hip muscles: an anteroposterior gradient

BACKGROUND

Despite the importance of the hip muscles in protecting against hip fracture and in the outcome of hip arthroplasty, the variability in their fat content has not been previously studied. Our objectives were to evaluate the variability in the fat content of the hip muscles in a population without myopathy or a need for hip surgery with the use of computed tomography (CT), to study the relationship between hip muscle fat content and physical performance, and to identify medical conditions and lifestyle habits associated with an increase in hip muscle fat content.

METHODS

Ten normal subjects without a relevant medical history and ninety-nine consecutive nonsurgical patients without myopathy (age, twenty-one to ninety-four years) underwent a nonenhanced CT scan of the pelvis. Patients were asked to perform physical tests (six-meter walk, repeated chair stands, and Trendelenburg test), and their level of physical activity and medical history were recorded. Evaluation of the fat content of the hip muscles was based on the analysis of four reproducible and representative CT slices with use of custom software.

RESULTS

The fat content varied among the muscles, with an anteroposterior gradient from the hip flexors (mean, 2%) to the hip extensors (mean, 10%). This gradient increased after fifty years of age. Fat content also varied considerably among patients. Higher fat content was associated with poorer performance on physical tests, even after adjustment for the cross-sectional area of the muscle (p < 0.05). Higher fat content was also associated with greater age, higher body-mass index, and lower physical activity (p < 0.001).

CONCLUSIONS

The observed variability in the fat content of individuals without myopathy or a need for hip surgery should be useful for comparison with future studies of specific populations of patients, such as those with muscle weakness secondary to hip fracture or hip surgery. Simple lifestyle changes such as dietary restriction, increased physical activity, and vitamin D supplementation may decrease muscle fat content and improve physical performance in the elderly.

Exercise protects bone after stroke, or does it? A narrative review of the evidence

Physical inactivity contributes to accelerated bone loss after stroke, leading to heightened fracture risk, increased mortality, and reduced independence. This paper sought to summarise the evidence for the use of physical activity to protect bone in healthy adults and adults with stroke, and to identify international recommendations regarding any means of bone protection after stroke, in order to guide rehabilitation practice and future research. A search was undertaken, which identified 12 systematic reviews of controlled trials which investigated the effect of physical activity on bone outcomes in adults. Nine reviews included healthy adults and three included adults with stroke. Twenty-five current international stroke management guidelines were identified. High-impact loading exercise appears to have a site-specific effect on the microarchitecture of healthy postmenopausal women, and physical activity has a small effect on enhancing or maintaining bone mineral density in chronic stroke patients. It is not known whether this translates to reduce fracture risk. Most guidelines included recommendations for early mobilisation after stroke and falls prevention. Two recommendations were identified which advocated exercise for the prevention bone loss after stroke, but supporting evidence was limited. Research is required to determine whether targeted physical activity can protect bone from early after stroke, and whether this can reduce fracture risk.

Stepping towards prevention of bone loss after stroke: a systematic review of the skeletal effects of physical activity after stroke

Bone loss after stroke is pronounced, and contributes to increased fracture risk. People who fracture after stroke experience reduced mobility and increased mortality. Physical activity can maintain or improve bone mineral density and structure in healthy older adults, likely reducing fracture risk. The purpose of this systematic review was to investigate the skeletal effects of physical activity in adults affected by stroke. A search of electronic databases was undertaken. Selection criteria of trials were • prospective and controlled • physical activity-based intervention • participants with history of stroke, and • bone-related outcome measures. Effect sizes were calculated for outcomes of paretic and nonparetic limbs. Three of 349 identified records met the inclusion criteria. Small effect sizes were found in favor of physical activity in adults with chronic stroke (n=95, 40% female, average age 63·8 years, more than one-year poststroke). Patients in intervention groups had significantly higher changes in femoral neck bone mineral density, tibial cortical thickness and trabecular bone mineral content of the paretic limb, compared with controls (P<0·05). It is not known whether these benefits reduced fracture risk. There are limited studies investigating the skeletal effect of physical activity for adults poststroke. Given the increased risk of, and poor outcomes following a fracture after stroke, randomized trials are warranted to investigate the benefits of physical activity on bone, after stroke. Interventions are likely to be beneficial if implemented soon after stroke, when bone loss appears to be rapid and pronounced.

Atrophy and intramuscular fat in specific muscles of the thigh: associated weakness and hyperinsulinemia in stroke survivors

PURPOSE

Sarcopenia and increased fat infiltration in muscle may play a role in the functional impairment and high risk for diabetes in stroke. Our purpose was to compare muscle volume and muscle attenuation across 6 muscles of the paretic and nonparetic thigh and examine the relationships between intramuscular fat and insulin resistance and between muscle volume and strength in stroke patients.

METHODS

Stroke participants (70; 39 men, 31 women) aged 40 to 84 years, BMI = 16 to 45 kg/m(2) underwent multiple thigh CT scans, total body scan by DXA (dual-energy X-ray absorptiometry), peak oxygen intake (VO(2peak)) graded treadmill test, 6-minute walk, fasting blood draws, and isokinetic strength testing.

RESULTS

Muscle volume is 24% lower and subcutaneous fat volume is 5% higher in the paretic versus nonparetic thigh. Muscle attenuation (index of amount of fat infiltration in muscle) is 17% higher in the nonparetic midthigh than the paretic. The semitendinosis/semimembranosis, biceps femoris, sartorius, vastus (medialis/lateralis), and rectus femoris have lower (between 9% and 19%) muscle areas on the paretic than the nonparetic thigh. Muscle attenuation is 15% to 25% higher on the nonparetic than the paretic side for 5 of 6 muscles. The nonparetic midthigh muscle attenuation is negatively associated with insulin. Eccentric peak torque of the nonparetic leg and paretic leg are associated with the corresponding muscle volume.

CONCLUSIONS

The skeletal muscle atrophy, increased fat around and within muscle, and ensuing muscular weakness observed in chronic stroke patients relates to diabetes risk and may impair functional mobility and independence.

Association of muscle strength and bone mineral density in adult survivors of childhood acute lymphoblastic leukemia

OBJECTIVES

To investigate the association between bone mineral density (BMD) and muscle strength in survivors of childhood acute lymphoblastic leukemia (ALL), a population at increased risk for both decreased BMD and muscle strength from cancer and its treatment.

DESIGN

Cohort data from the St Jude Lifetime Cohort (SJLIFE) study.

SETTING

Department of Cancer Control at St Jude Children's Research Hospital.

PARTICIPANTS

Subjects were adults enrolled in St Jude Lifetime Cohort study and treated for childhood ALL between 1962 and 1999. As part of a comprehensive evaluation, participants had dual energy x-ray absorptiometry (DEXA) scans and muscle strength testing. The participants consisted of 261 women and 232 men who were 20.4 to 49.8 years old (median, 35.7y), and 12.7 to 46.5 years from diagnosis of childhood ALL (median, 27.2y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

BMD was determined by DEXA scan. Muscle strength of upper and lower extremities was assessed with physical performance testing.

RESULTS

After adjusting for covariates, we found significant (P<0.005) associations between BMD and muscle strength in lower extremities (R(2) range, 0.33-0.40) and strong, significant associations in upper extremities (left-side R(2)=0.558; right-side R(2)=0.560).

CONCLUSIONS

Muscle strength was associated with BMD in the extremities of long-term survivors of childhood ALL, a finding suggesting that muscle strengthening interventions may improve bone health in them.

Bone mineral density in adults disabled through acquired neurological conditions: a review

This article is a review of the changes in bone mineral density (BMD), which occur in a number of acquired neurological conditions resulting in disability. For each of spinal cord injury, stroke, multiple sclerosis, Parkinson's disease, and traumatic brain injury, the following aspects are discussed, where information is available: prevalence of low BMD according to World Health Organization diagnostic categories and recommended diagnostic method, prevalence based on other diagnostic tools, comparison of BMD with a control population, rate of decline of BMD following onset of the neurological condition, factors influencing decline; mechanism of bone loss, and fracture rates. The common risk factors of immobilization and vitamin D deficiency would appear to cross all disability groups, with the most rapid phase of bone loss occurring in the acute and subacute phases of each condition.

Whole body vibration therapy in fracture prevention among adults with chronic disease

Due to various physical impairments, individuals with chronic diseases often live a sedentary lifestyle, which leads to physical de-conditioning. The associated muscle weakness, functional decline and bone loss also render these individuals highly susceptible to falls and fragility fractures. There is an urgent need to search for safe and effective intervention strategies to prevent fragility fractures by modifying the fall-related risk factors and enhancing bone health. Whole body vibration (WBV) therapy has gained popularity in rehabilitation in recent years. In this type of treatment, mechanical vibration is delivered to the body while the individual is standing on an oscillating platform. As mechanical loading is one of the most powerful stimuli to induce osteogenesis, it is proposed that the mechanical stress applied to the human skeleton in WBV therapy might be beneficial for enhancing bone mass. Additionally, the vibratory signals also constitute a form of sensory stimulation and can induce reflex muscle activation, which could potentially induce therapeutic effects on muscle strength and important sensorimotor functions such as postural control. Increasing research evidence suggests that WBV is effective in enhancing hip bone mineral density, muscle strength and balance ability in elderly patients, and could have potential for individuals with chronic diseases, who often cannot tolerate vigorous impact or resistance exercise training. This article aims to discuss the potential role of WBV therapy in the prevention of fragility fractures among people with chronic diseases.

Loss of Skeletal Muscle Mass after Stroke: a Systematic Review

Loss of muscle mass after stroke has implications for strength and functional ability and may also contribute to impaired glucose metabolism. Therefore, prevention of muscle loss is desirable. Before interventions to prevent loss of muscle can be designed and evaluated, the expected rate, magnitude and timing of muscle loss need to be understood. A systematic search was undertaken to identify all studies that investigated changes in skeletal muscle mass, volume or cross-sectional area in people after stroke. Studies that used either direct measures of muscle size (computer tomography, magnetic resonance imaging or ultrasound) or measures of lean tissue mass (dual X-ray absorptiometry) were included. Fourteen trials were found and the results were pooled for differences in lean tissue mass between the paretic and the nonparetic leg and arm as well as differences in the midthigh cross-sectional area. In individuals at least 6-month post-stroke, there was significantly less lean tissue mass in the paretic compared with the nonparetic lower limb (MD 342.3 g, 95% confidence interval 247.0–437.6 g) and upper limb (MD 239.9 g, 95% confidence interval 181.7–298.2 g), and significantly less midthigh muscle cross-sectional area (MD 15.4 cm2, 95% confidence interval 13.8–16.9 cm2). There were insufficient data to pool with regard to change in muscle mass over time. There is a significant difference in the regional muscle mass in the paretic vs. the nonparetic limb in individuals greater than 6-months poststroke but little is known about how early and how quickly changes in muscle mass occur.

Fitness and Mobility Exercise (FAME) Program for stroke

Given the potential of exercise to positively influence so many physical and psychosocial domains, the Fitness and Mobility Exercise (FAME) Program was developed to address the multiple impairments arising from the chronic health condition of stroke. We present the details of this exercise program and the evidence which has shown that the FAME Program can improve motor function (muscle strength, balance, walking), cardiovascular fitness, bone density, executive functions and memory. The FAME Program can help to improve the physical and cognitive abilities of people living with a stroke and reduce the risk of secondary complications such as falls, fractures and heart disease.

The Effects of Treadmill Exercise Training on Hip Bone Density and Tibial Bone Geometry in Stroke Survivors: A Pilot Study

Background. Individuals with stroke often sustain bone loss on the hemiparetic side and are prone to fragility fractures. Exercise training may be a viable way to promote bone mineral density (BMD) and geometry in this population. Objective. This was a pilot study to evaluate the effects of a 6-month treadmill exercise program on hip BMD and tibial bone geometry in chronic stroke survivors. Methods. Twenty-one individuals with chronic stroke, with a mean age of 64.5 years and mean poststroke duration of 8.3 years participated in the study. The treatment group underwent a treadmill gait exercise program (two 1-hour sessions per week for 6 months), whereas the control group participated in their usual self-selected activities in the community. The primary outcomes were hip BMD and bone geometry of the midshaft tibia on the paretic side, whereas the secondary outcomes were gait velocity, endurance, leg muscle strength, balance self-efficacy, and physical activity level. Mann-Whitney U tests were used to compare the change in all outcome variables between the 2 groups after treatment. Results. Significant between-group differences in change scores of tibial cortical thickness ( P = .016), endurance ( P = .029), leg muscle strength on the paretic side ( P < .001) and nonparetic side ( P < .001), balance self-efficacy ( P = .016), and physical activity level ( P = .023) were found. Conclusion . The treadmill exercise program induced a modest improvement in tibial bone geometry in individuals with chronic stroke. Further studies are required to explore the optimal training protocol for promoting favorable changes in bone parameters following stroke.

Trunk muscle strength, but not trunk rigidity, is independently associated with bone mineral density of the lumbar spine in patients with Parkinson's disease

Previous literature suggested that muscle forces applied to the skeleton may be an important factor in increasing bone mineral density (BMD). This purpose of this study was to determine whether trunk rigidity and trunk muscle strength were associated with lumbar spine BMD in patients with Parkinson's disease (PD). Forty-three PD patients and 29 controls participated in this study. Dual-energy X-ray absorptiometry was used to measure lumbar spine BMD of PD patients. Additionally, an isokinetic dynamometer was used to evaluate trunk rigidity and trunk muscle strength of all subjects. The results showed that PD patients had significantly lower trunk muscle strength, but more trunk rigidity than controls by 46.6 and 162.8%, respectively (P < 0.001). In bivariate correlation analysis, lumbar spine BMD was significantly related to trunk muscle strength (r = 0.475, P = 0.001), but not trunk rigidity (r = 0.271, P = 0.079). In multiple regression analysis, after adjusting for relevant factors, only trunk muscle strength remained independently associated with lumbar spine BMD, accounting for 10.0% of the variance (R(2) = 0.342, F(5,) (37) = 3.838, P = 0.007). Trunk muscle strength, but not trunk rigidity, is independently associated with lumbar spine BMD in patients with PD. Further randomized controlled studies are required to determine whether trunk muscle strengthening exercise is effective in enhancing lumbar spine BMD.