Determinants of bone mineral density in immobilization: a study on hemiplegic patients

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.

Changes in bone mineral density in unconscious immobile stroke patients from the acute to chronic phases of brain diseases

Objectives

Decreased bone mineral density (BMD) is observed in immobile stroke patients. But it is not clarified yet how rapidly BMD reduction occurs or what the most influencing factor to BMD loss is.

Methods

BMDs in the lumbar vertebrae and the proximal femur of the paralyzed side were measured in 100 immobile stroke patients at 1 week (0 month), 1 month, and 2 months after admission. The levels of serum calcium, phosphorous, 25-hydroxyvitamin D, and urine cross-linked N-telopeptide of type I collagen (NTx) were also measured.

Results

The average age of patients was 75.0 ± 11.4 years (31–94 years). No BMD reduction was identified in the lumbar vertebrae in 2 months; however, BMD in the femur significantly decreased in 2 months in female patients (P < 0.05). Serum calcium and phosphorous levels remained within the normal range during hospitalization, and 25-hydroxyvitamin D value rose in 2 months. Urine NTx significantly increased in both males and females in 2 months (male: P < 0.05, female: P < 0.01).

Conclusions

While there was no significant change in lumbar spine BMD in the 2 month period of immobilization after stroke, BMD in the proximal femur showed a significant reduction, particularly in women. The differential loss of BMD in the 2 regions of interest could possibly be due to the physical forces acting on different body parts during mobilization and nutritional factors. More studies are needed with larger study samples and prolonged follow-up to check the accuracy of these observations.

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.

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.

Does Hip Bone Density Differ between Paretic and Non-Paretic Sides in Hemiplegic Stroke Patients? and Its Relationship with Physical Impairment

Background

Bone loss after stroke escalates the risk of fractures, mainly in the hip, leading to further disability in individuals with stroke. We aimed to investigate the skeletal effect of bone mineral density (BMD) based on the duration of onset of stroke, compare the BMD of the paretic and non-paretic sides, and elucidate the relationship between BMD and disability variables.

Methods

The 31 male hemiplegic stroke patients between 20 and 70 years of age with cerebral infarction or hemorrhage were considered in this study. Subacute and chronic cases included 13 and 18 patients with lag time from the onset of 1 to 6 months and beyond 6 months, respectively. BMD in the lumbar, paretic, and non-paretic hip as well as the disability variables were analyzed retrospectively.

Results

The subacute group showed a significant reduction in the femoral neck BMD on the paretic side compared to that on the non-paretic side based on T-scores (P=0.013). Bone loss was significantly correlated with lower limb muscle strength and overall physical impairment (P<0.05). The chronic group demonstrated significant reduction in femur neck and total femur BMD on the paretic side compared to that on the non-paretic side based on T-scores (P=0.002 and P<0.001, respectively). T-scores of BMD in the chronic phase were not significantly associated with the clinical parameters.

Conclusions

Early screening of bilateral hip BMD in the early stages after stroke, monitoring, and timely implementation of prevention strategies are important to minimize subsequent bone loss and prevent possible complications in patients who experience stroke.

Association between post-stroke disability and 5-year hip-fracture risk: The Women's Health Initiative

BACKGROUND

Hip fractures are a significant post-stroke complication. We examined predictors of hip fracture risk after stroke using data from the Women's Health Initiative (WHI). In particular, we examined the association between post-stroke disability levels and hip fracture risk.

METHODS

The WHI is a prospective study of 161,808 postmenopausal women aged 50-79 years. Trained physicians adjudicated stroke events and hip fractures. Our study included stroke survivors from the observational and clinical trial arms who had a Glasgow Outcome Scale of good recovery, moderately disabled, or severely disabled and survived more than 7 days post-stroke. Hip fracture-free status was compared across disability levels. Secondary analysis examined hip fracture risk while accounting for competing risk of death.

RESULTS

Average age at time of stroke was 74.6±7.2 years; 84.3% were white. There were 124 hip fractures among 4,640 stroke survivors over a mean follow-up time of 3.1±1.8 years. Mortality rate was 23.3%. Severe disability at discharge (Hazard Ratio (HR): 2.1 (95% Confidence Interval (CI): 1.4-3.2), but not moderate disability (HR: 1.1 (95%CI: 0.7-1.7), was significantly associated with an increased risk of hip fracture compared to good recovery status. This association was attenuated after accounting for mortality. White race, increasing age and higher Fracture Risk Assessment Tool (FRAX)-predicted hip fracture risk (without bone density information) were associated with an increased hip fracture risk. After accounting for mortality, higher FRAX risk and white race remained significant.

CONCLUSION

Severe disability after stroke and a higher FRAX risk score were associated with risk of subsequent hip fracture. After accounting for mortality, only the FRAX risk score remained significant. The FRAX risk score appears to identify stroke survivors at high risk of fractures. Our results suggest that stroke units can consider the incorporation of osteoporosis screening into care pathways.

Stroke and osteoporosis: a Taiwan cohort study

Background

Osteoporosis and stroke are major health problems that have potentially overlapping pathophysiological mechanisms. The aim of this study was to estimate osteoporosis risk in Taiwan patientswho had a stroke.

Method

This study retrieved data contained in the Taiwan National Health Insurance Research Database for a population-based sample of consecutive patients either hospitalised for stroke or treated for stroke on an outpatient basis. A total of 7550 newly diagnosed patientswho had a stroke were enrolled during 1996–2010. Osteoporosis risk in these patients was then compared with a matched group of patients who had not had a stroke randomly selected from the database at a ratio of 1:4 (n=30 200). The relationship between stroke history and osteoporosis risk was estimated with Cox proportional hazard regression models.

Results

During the follow-up period, osteoporosis developed in 1537 patients who had a stroke and in 5830 patients who had not had a stroke. The incidence of osteoporosis for cohorts with and without stroke was 32.97 and 14.28 per 1000 person-years, respectively. After controlling for covariates, the overall risk of osteoporosis was 1.82-fold higher in the stroke group than in the non-stroke group. The relative osteoporosis risk contributed by stroke had apparently greater impact among male gender and younger age groups.

Conclusion

History of stroke is a risk factor for osteoporosis in Taiwan. Much attention to stroke-targeted treatment modalities might minimise adverse outcomes of osteoporosis.

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.

Bone microstructure is significantly altered in CRPS-affected distal tibiae as detected by HR-pQCT: a retrospective cross-sectional study

In the course of complex regional pain syndrome (CRPS), local osteopenia in the subchondral/subcortical areas of the affected limb represents a central manifestation. Mechanistic aspects of CRPS-associated pathologies remain unclear, and knowledge about bone morphology in CRPS-affected areas is rare. The aim of this study was to assess trabecular and cortical bone microstructure in patients with CRPS of the distal tibiae. We retrospectively analysed 14 women diagnosed with unilateral CRPS type I of the lower limb whose affected and unaffected distal tibiae were examined by high-resolution peripheral quantitative computed tomography (HR-pQCT). Laboratory tests included serum levels of calcium, phosphate, 25-hydroxyvitamin D, bone alkaline phosphatase, parathyroid hormone, osteocalcin and urinary levels of deoxypyridinoline (DPD). Bone mineral density was measured by dual-energy X-ray absorptiometry (DXA) at the lumbar spine and both proximal femurs. Average urinary DPD levels, a biochemical marker of bone resorption, were elevated in the examined patient cohort (7.1 ± 1.9 nmol/mmol, reference 3.0-7.0 nmol/mmol). According to HR-pQCT, CRPS-affected distal tibiae showed significantly lower values of cortical BMD and cortical thickness compared to the unaffected contralateral side. Also, bone volume relative to total volume was significantly lower. Trabecular number and trabecular thickness tended to be lower in the affected tibiae. CRPS is associated with significant alterations in bone microstructure of the affected tibiae. Increased bone resorption seems to play a crucial role within a multifactorial process of CRPS-mediated bone atrophy. HR-pQCT could possibly serve as a diagnostic tool in specific CRPS therapy.

Quantitative Ultrasound of Proximal Phalanxes in Childhood Acute Lymphoblastic Leukemia Survivors

Reduced bone mineral density (BMD) is a well-known complication in childhood acute lymphoblastic leukemia (ALL) survivors; the optimal method to assess BMD is still debated. We studied BMD by quantitative ultrasound (QUS) in 72 ALL survivors, and evaluated any correlation with cumulative doses of steroids and cytotoxic agents. Mean age at diagnosis was 61±45 months, while mean age at QUS was 318.3±129.6 months; mean period of follow-up was 41.2±37.8 months. Mean amplitude-dependent speed of sound z-score was -1.22±1.19. Ten survivors (13.8%) presented a z-score below -2 SD. A negative correlation was found between amplitude-dependent speed of sound z-score and age at diagnosis (P=0.01). A positive correlation was observed with length of follow-up (P=0.01). No correlation was found with cytotoxic drugs. This study represents the largest cohort of childhood ALL survivors studied by QUS. Our results suggest that QUS for its characteristics of being radiation free may be an effective option to assess BMD in pediatric age. In addition, our data outline the importance to improve the awareness about the specific expression of this complication in the pediatric age, concerning the major determinants of bone impairment, which are the disease itself and the phase of bone growth when the disease occurs.

Bone loss at the distal femur and proximal tibia in persons with spinal cord injury: imaging approaches, risk of fracture, and potential treatment options

Persons with spinal cord injury (SCI) undergo immediate unloading of the skeleton and, as a result, have severe bone loss below the level of lesion associated with increased risk of long-bone fractures. The pattern of bone loss in individuals with SCI differs from other forms of secondary osteoporosis because the skeleton above the level of lesion remains unaffected, while marked bone loss occurs in the regions of neurological impairment. Striking demineralization of the trabecular epiphyses of the distal femur (supracondylar) and proximal tibia occurs, with the knee region being highly vulnerable to fracture because many accidents occur while sitting in a wheelchair, making the knee region the first point of contact to any applied force. To quantify bone mineral density (BMD) at the knee, dual energy x-ray absorptiometry (DXA) and/or computed tomography (CT) bone densitometry are routinely employed in the clinical and research settings. A detailed review of imaging methods to acquire and quantify BMD at the distal femur and proximal tibia has not been performed to date but, if available, would serve as a reference for clinicians and researchers. This article will discuss the risk of fracture at the knee in persons with SCI, imaging methods to acquire and quantify BMD at the distal femur and proximal tibia, and treatment options available for prophylaxis against or reversal of osteoporosis in individuals with SCI.

Change of Bone Mineral Density and Relationship to Clinical Parameters in Male Stroke Patients

OBJECTIVE

To investigate the clinical characteristics that significantly contribute to a decreased bone mineral density (BMD), the BMD changes and clinical characteristics of men who experienced a stroke between the ages of 50 years and 65 years were studied between 3 months and 4 months after the stroke.

METHODS

Subjects had a brain hemorrhage or a cerebral infarction. Only men aged 50 years to 65 years were included to eliminate postmenopausal osteoporosis and to eliminate the influence of senile osteoporosis. All subjects underwent a BMD test between 3 months and 4 months after their strokes. Also, patients with a medication history that might have caused a secondary osteoporosis before a stroke were excluded.

RESULTS

The BMD for the lumbar spine and hemiplegic side of the femoral neck correlated significantly with the results of the manual muscle test (MMT) of the hemiplegic lower extremity and the Modified Barthel Index (MBI) score. This result suggests that the immobility from the decreased muscle strength and the weakened daily functionality might have reduced the BMD. According to a multiple linear regression analysis, the MBI score is significantly correlated with the lumbar BMD. The BMD of the hemiplegic femoral neck is significantly correlated with the MMT and the MBI score.

CONCLUSION

This study showed that BMD monitoring should be considered in male stroke patients, especially for patients with a high dependency in daily functions and a decreased muscle strength in the hemiplegic lower extremity.

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.

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.

Prevalence and associated factors of T-score discordance between different sites in Iranian patients with spinal cord injury

OBJECTIVES

The present study was conducted to determine the prevalence of T-score discordance and its risk factors in a group of patients with spinal cord injury in a university teaching hospital in the Iranian capital of Tehran.

METHODS

This cross-sectional study was conducted on paraplegic men undergoing bone density testing in an outpatient clinic at a hospital in the Iranian capital, Tehran, between March 2011 and 2012. A questionnaire on demographic and anthropometric characteristics, including age, height, weight, engagement in physical activity and personal smoking habits, was filled out for each subject. All the subjects underwent bone mineral density measurement and blood samples were sent for laboratory testing.

RESULTS

Major T-score discordance between two sites was noted in 54 (41.22%) patients. Multivariate logistic regression revealed that every unit increase in serum calcium levels, as the only factor influencing T-score discordance, was associated with a 2.49-fold increased risk in T-score discordance in the area. As for the spine and radius, BMI was the only influencing factor as every unit increase in BMI was associated with a 14% lower risk for T-score discordance in these regions. Body mass index was the only factor, based on the multivariate model, affecting the risk of developing T-score discordance between two sites.

CONCLUSION

Our study revealed the high prevalence of T-score discordance in patients with spinal cord injury. Physicians should therefore be encouraged to perform BMD at three sites when visiting patients with such injuries.

Bone ultrasound velocity in pediatric intensive care unit: a pilot study

BACKGROUND

Bone loss has been documented in adults in intensive care wards. Children admitted to pediatric intensive care units (PICU) are also exposed to many potential risk factors for bone loss such as immobilization, catabolic state, and nutritional depletion. Quantitative ultrasound technique that measures speed of sound (SOS) correlates with bone mineral density (BMD) and strength. Herein is a clinical prospective longitudinal, observational pilot study to evaluate early bone changes that occur during the first few days of PICU admission.

METHODS

Children are hospitalized in a pediatric intensive under general anesthesia and muscle paralysis. Bone SOS at the mid-shaft tibia was measured on the first day of hospitalization and on days 2 to 3 thereafter.

RESULTS

Nineteen children were studied. Bone SOS decreased during the first 3 days of hospitalization from 3,297 ± 315 to 3,260 ± 311 m/min (p < 0.05). The decrease was approximately 1% of the original SOS over the first 2 to 3 days of admission.

CONCLUSION

There is a significant decrease in bone strength after 3 days in pediatric patients admitted to an intensive care department. Longitudinal studies of a larger group of children are necessary to determine the clinical meaning of the results and to possibly evaluate preventive approaches.

Bone loss in chronic hemiplegia: a longitudinal cohort study

The purpose of this study was to evaluate hemiplegic stroke patients in terms of long-term changes in bone mineral density and related factors. We conducted a longitudinal cohort study, involving 57 first-stroke patients (40 males) with chronic hemiplegia (for more than 12mo), at a university rehabilitation center in the city of São Paulo, Brazil. Bone loss, body composition, lean mass, and fat mass were evaluated at 2 time points (mean interval, 16mo). Bone loss was significantly greater in paretic forearms than in nonparetic forearms (p=0.001) and in patients having suffered strokes more recently (p=0.015). We found no difference between paretic and nonparetic femurs. Femoral bone loss was significantly greater in patients using anticoagulants or anticonvulsants (p=0.025) and in those with greater spasticity (p=0.040), regardless of the time since stroke. Our results provide additional evidence that hemiplegic stroke patients have progressive bone loss and that such bone loss is more common in the arms than in the legs. Patients with poststroke hemiplegia should be densitometric monitored mainly in paretic arm and treated for bone loss, with attention to the determinants identified in this study.

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.

Minimal trauma fractures: lifting the specter of misconduct by identifying risk factors and planning for prevention

Minimal trauma fractures are an unfortunate, yet not uncommon, event for frail elderly individuals in long term care facilities. These fractures result in significant morbidity including pain and loss of function along with significantly increased mortality. Further concern exists for the medico-legal issues raised after a minimal trauma fracture is discovered. The controversy at hand is whether such fractures are primarily the result of inadequate, careless, or abusive care practices. We build a case to the contrary. Although the data regarding this condition are limited, there exists a reasonable evidence base to identify an at-risk patient population. We present a representative case and subsequent literature review of minimal trauma fractures to illustrate the condition, including risk factors, mode of presentation, and patient outcomes. No direct research has been conducted on the pathophysiology of these fractures. Extrapolating from other similar conditions and likely associated comorbid illnesses, we explore possible physiologic explanations for their occurrence. Again, no direct investigation into prevention or treatment of minimal trauma fractures has been published. Instead, we consider a variety of pharmacologic and nonpharmacologic interventions that may modify the risk for minimal trauma fractures considering the previously identified risk factors and probable pathophysiologic changes leading to fracture development. We propose that reducing minimal trauma fractures in the frail elderly nursing home population will require careful staff education, close attention to identify at-risk patients, and implementation of select interventions aimed at preventing such fractures.

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.

Poststroke fractures in a bi-ethnic community

BACKGROUND

Mexican Americans have increased risks of stroke and lower fractures compared with non-Hispanic whites, but little is known about poststroke fracture risk in Mexican Americans. The objective of this study was to describe poststroke fracture risk in a bi-ethnic population and to compare risk by ethnicity.

METHODS

In the Brain Attack Surveillance in Corpus Christi Project, strokes were identified through hospital surveillance (2000-2004) and validated by neurologists (n = 2389). Inpatient claims for fractures were ascertained (2000-2004) and cross-referenced with strokes. Survival free from fracture (any and hip) poststroke was estimated and compared by ethnicity. Cox regression was used to test the association of ethnicity and fracture risk adjusted for confounders. Interaction terms for ethnicity and age were considered.

RESULTS

The mean age was 71 years (SD, 13 yrs); 54% were Mexican American and 52% were women. The mean follow-up was 4 years. There were 105 fractures (33% of the hips). Survival free of any fracture and of hip fracture did not differ by ethnicity. Increasing age, female gender, intracerebral hemorrhage, and greater stroke severity were associated with risk of any fracture, but ethnicity was not. Ethnicity was associated with risk of hip fracture, but this association was modified by age (P = .02), where Mexican Americans were protected from hip fractures at younger but not older ages.

CONCLUSIONS

Stroke patients were at high risk for fractures, with a 10% risk at 5 years. Mexican Americans were protected from hip fractures at younger but not older ages. Both elderly Mexican Americans and non-Hispanic whites should be targeted for poststroke fracture prevention.

Osteoporosis in multiple sclerosis

Fractures resulting from osteoporosis are a major cause of morbidity and mortality in the developed world. People with multiple sclerosis experience reduced mobility and are susceptible to falls. Glucocorticoid use and reduced mobility are known risk factors for osteoporosis. This paper is a review of osteoporosis in people with multiple sclerosis, looking at its prevalence, risk factors and possible mechanisms. We also review management guidelines for osteoporosis in the general population and use these to propose guidelines for osteoporosis management amongst multiple sclerosis patients. A number of studies have examined the incidence of reduced bone mineral density amongst people with multiple sclerosis; the majority provide convincing evidence that bone mineral density is significantly reduced in multiple sclerosis patients. The most significant risk factors appear to arise from the chronic disease process of multiple sclerosis and not from glucocorticoid use. There are currently no guidelines or consensus as how best to treat osteoporosis amongst multiple sclerosis patients despite their being at an increased risk. We propose an algorithm for the screening and treatment of osteoporosis in people with multiple sclerosis.

Skeletal and body composition changes in hemiplegic patients

Hemiplegic patients are prone to bone loss and alterations in fat and lean mass, which ultimately affect their rehabilitation status and propensity in bone fractures. The present study aimed to evaluate body composition and bone mineral density (BMD) in stroke patients within 1st year post-stroke. Fifty-eight hemiplegic patients (36 men and 22 women) were enrolled in this prospective study. Dual-energy X-ray absorptiometry was used to assess total-body and lower-extremity BMDs (g/cm(2)), lean mass (g), and fat mass (g) after 3, 6 and 12 mo of stroke that led to hemiplegia. The Modified Ashworth Scale and the functional ambulation category were used to evaluate spasticity and ambulatory category of patients, respectively. Both sexes exhibited total-body and paretic lower-limb BMD loss, fat mass gain, and lean mass waste during the 1st 12 mo poststroke, and in most cases, statistically significant differences were found between 3 and 6 mo; however, the pattern of changes was different between males and females. Therefore, it is suggested that disability because of hemiplegia led to alterations in muscle function, which triggered skeletal and body composition changes and rendered these patients particularly prone to increased fracture risk.

Osteoporosis in Long-Term Care Residents with Multiple Sclerosis

OBJECTIVE

To assess the fracture risk of long-term care residents with multiple sclerosis (MS) using ultrasound heel-scan technology and identification of risk factors and areas where intervention by a pharmacist might affect patient outcomes.

DESIGN

Bilateral-heel scans were performed on all patients who consented to take part in the study. A retrospective review of each subject's medical records was performed to identify known risk factors for osteoporosis.

SETTING

A long-term care facility in Omaha, Nebraska.

PARTICIPANTS

All patients with a primary diagnosis of MS residing at the facility were eligible for participation. Of 11 patients identified, 10 consented to participate.

MAIN OUTCOME MEASURES

T-scores of the right and left heel as determined by ultrasound-heel scan were used to determine if study participants met criteria for osteopenia or osteoporosis as set forth by the World Health Organization.

CONCLUSION

Patients in our population who have MS are at high risk for fracture. There are several areas in which pharmacists can intervene to prevent fracture and improve patient outcomes, including administration of heel scans for persons believed to be at risk, recommendation of over-the-counter supplements, and education of both patients and health care practitioners.

VA-based survey of osteoporosis management in spinal cord injury

OBJECTIVE

Although osteoporosis is common following spinal cord injury (SCI), no guidelines exist for its treatment, diagnosis, or prevention. The authors hypothesized that wide variations in diagnosis and treatment practices result from the absence of guidelines. This study sought to characterize the diagnosis and management practices within the VA health care system for osteoporosis following SCI.

DESIGN

Online survey regarding osteoporosis management in SCI composed of 27 questions designed to gather information on responder demographics, osteoporosis diagnostics, and treatment options.

SETTING

VA health care system.

PARTICIPANTS

VHA National SCI Staff Physicians and VHA National SCI Nurses (total n = 450) were sent an email with an invitation to participate.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

Practice patterns were assessed, including factors associated with ordering a clinical workup and prescribing osteoporosis treatment.

RESULTS

The response rate was 28%. Ninety-two prescribing practitioners (physicians, nurse practitioners, and physician assistants) were included in the analysis. Of these respondents, 50 (54%) prescribe medications for SCI-induced bone loss; 39 (42%) prescribe bisphosphonates and 46 (50%) prescribe vitamin D. There were 54 (59%) respondents who routinely order diagnostic tests, including dual energy x-ray absorptiometry scans in 50 (54%). Variations in practice were not explained by age, gender, or years practicing SCI medicine. Many respondents (23%) reported barriers to osteoporosis testing including lack of scanning protocols, cost, wheelchair inaccessibility of scanning facilities, and lack of effective treatment guidelines once osteoporosis is diagnosed.

CONCLUSIONS

Despite an absence of screening and treatment guidelines, more than half of all respondents are actively diagnosing and treating osteoporosis with bisphosphonates within the VA health care setting. These data suggest that evidence-based practice guidelines are necessary to reduce practice variations and improve clinical care for this population.

VA-based survey of osteoporosis management in spinal cord injury

OBJECTIVE

Although osteoporosis is common following spinal cord injury (SCI), no guidelines exist for its treatment, diagnosis, or prevention. The authors hypothesized that wide variations in diagnosis and treatment practices result from the absence of guidelines. This study sought to characterize the diagnosis and management practices within the VA health care system for osteoporosis following SCI.

DESIGN

Online survey regarding osteoporosis management in SCI composed of 27 questions designed to gather information on responder demographics, osteoporosis diagnostics, and treatment options.

SETTING

VA health care system.

PARTICIPANTS

VHA National SCI Staff Physicians and VHA National SCI Nurses (total n = 450) were sent an email with an invitation to participate.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

Practice patterns were assessed, including factors associated with ordering a clinical workup and prescribing osteoporosis treatment.

RESULTS

The response rate was 28%. Ninety-two prescribing practitioners (physicians, nurse practitioners, and physician assistants) were included in the analysis. Of these respondents, 50 (54%) prescribe medications for SCI-induced bone loss; 39 (42%) prescribe bisphosphonates and 46 (50%) prescribe vitamin D. There were 54 (59%) respondents who routinely order diagnostic tests, including dual energy x-ray absorptiometry scans in 50 (54%). Variations in practice were not explained by age, gender, or years practicing SCI medicine. Many respondents (23%) reported barriers to osteoporosis testing including lack of scanning protocols, cost, wheelchair inaccessibility of scanning facilities, and lack of effective treatment guidelines once osteoporosis is diagnosed.

CONCLUSIONS

Despite an absence of screening and treatment guidelines, more than half of all respondents are actively diagnosing and treating osteoporosis with bisphosphonates within the VA health care setting. These data suggest that evidence-based practice guidelines are necessary to reduce practice variations and improve clinical care for this population.

Bone resorption in stroke and institutionalized subjects

Stroke increases the risk of hip fracture on the affected side. Although bone is lost by 1 year, rapidity of onset and relationship with immobility are uncertain. Using the bone resorption marker urinary cross-linked N telopeptide of type I collagen (uNTx), we examined bone resorption in the first 4 weeks after stroke, relating uNTx with bone density and mobility in subjects over 60 years. Two separate control groups acted as comparators, healthy (HC) and institutionalized (IC) controls, the latter to control for the effects of institutionalization. uNTx, urinary calcium (both related to creatinine and log-transformed), heel bone mineral density (BMD), Tinetti scores, and Barthel scores for prestroke function were measured. Log uNTx/Cr was lower in males compared with females, but this difference was not evident in stroke or IC subjects. Log uNTx/Cr was inversely related with BMD in females from both control groups and in male stroke subjects. Tinetti scores were divided into tertiles and were lower in stroke than IC subjects (P < 0.01). Log uNTx/Cr was similar in stroke and IC subjects in the lowest Tinetti tertile. Log uNTx/Cr was higher in stroke subjects of both sexes in the lowest tertile compared with the higher two tertiles combined (P < 0.05) and higher in all tertiles compared with HC subjects (P < 0.05). Subjects with a prestroke Barthel index of < or = 17 had higher log uNTx/Cr compared with HCs. Log uCa/Cr was higher only in male stroke patients. Bone resorption in stroke starts early, and measures to reduce this are merited.

Bone mineral density alterations in upper and lower extremities 12 months after stroke measured by peripheral quantitative computed tomography and DXA

To evaluate the loss of trabecular and cortical bone mineral density (BMD) and geometric parameters of bone strength expressed by stress-strain index (SSI) in the proximal and distal forearm and the alterations of BMD in the hip of hemiplegic patient and 12 mo after stroke. Sixty-seven hemiplegic patients (43 men and 24 women) with a history of single completed strokes associated with unilateral weakness were enrolled in this prospective study. All patients underwent bone densitometry measurements at 3, 6, and 12 mo after the initial episode of stroke. Both paretic and normal forearms were examined by peripheral quantitative computed tomography (pQCT) at the 4% and 20% sites of the forearm length and both hips were examined by dual-energy X-ray absorptiometry (DXA) including the area of femoral neck and greater trochanter. The diagnosis of stroke was confirmed by cranial computed tomography. Motor function was assessed by the functional ambulation category (FAC) and spasticity by the modified Ashworth scale (MAS). We found statistically significant trabecular and cortical bone density reductions during the course of our study in the forearm, which was more profound on the paretic side. Trabecular bone loss and SSI measured at 4% of the paretic forearm in the male group represented a 12-mo decrease of 14.01% and 28.61%, respectively, and in the female group 9.29% and 19.17%, respectively. Cortical bone and SSI measured at the 20% site of paretic forearm in the male group corresponded to a 12-mo decrease of 4.02% and 7.43%, respectively, and in the female group 2.59% and 6.97%, respectively. Paretic femoral neck and trochanter measurements in males showed a reduction of 11.76% and 10.38%, respectively, and in females 13.04% and 12.6%, respectively. A significant loss of BMD and bone strength was found during the first year after stroke in both trabecular and cortical bone at the forearm and at the neck and great trochanter on the paretic hip. Most prominent BMD reduction was evident in men compared with perimenopausal women in the same age.

Can early onset bone loss be effectively managed in post-stroke patients? An integrative review of the evidence

BACKGROUND

bone loss post-stroke can lead to an increased risk of fracture. Fractures compound the effects of a stroke, resulting in greater dependency for the individual and an increased burden for health and social care.

OBJECTIVES

to identify risk factors for bone loss post-stroke and appraise bone loss or fracture risk reduction interventions. To develop a research agenda that informs the design and development of risk reduction strategies.

DESIGN

an integrative review.

METHODS

the search strategies used in Medline, Embase, AMED and CINAHL from 1966 to July 2006 identified 530 records. Ninety-nine papers with a focus on risk factors or interventions to prevent bone loss or fractures post-stroke were identified. Hand searching and scoping grey literature produced 59 additional papers. Data analysis, including data reduction and data display using matrices, enabled patterns and themes to be derived from differing study designs.

RESULTS

risk factors for bone loss post-stroke are reduced mobility, vitamin D deficiency, gender and time since stroke. Early mobilisation post-stroke may reduce bone loss, and so avoid fractures, but evidence is needed. Providing vitamin D supplements and Bisphosphonates in post-stroke patients tends to reduce bone loss, but larger treatment trials are required.

CONCLUSIONS

the evidence base for bone loss management post-stroke is limited. Large, prospective, multi-centre, longitudinal studies are needed to clarify optimum treatments to reduce post-stroke bone loss, and test the effects on clinical outcomes. A 'skeletal health' checklist to aid implementation of treatments within stroke rehabilitation has been suggested but not yet developed.

Effect of anti-NGF antibodies in a rat tibia fracture model of complex regional pain syndrome type I

Tibia fracture in rats evokes chronic hindpaw warmth, edema, allodynia, and regional osteopenia resembling the clinical characteristics of patients with complex regional pain syndrome type I (CRPS I). Nerve growth factor (NGF) has been shown to support nociceptive and other types of changes found in neuropathic pain models. We hypothesized that anti-NGF antibodies might reduce one or more of the CRPS I-like features of the rat fracture model. For our studies one distal tibia of each experimental rat was fractured and casted for 4 weeks. The rats were injected with anti-NGF or vehicle at days 17 and 24 post-fracture. Nociceptive testing as well as assessment of edema and hindpaw warmth were followed during this period. Molecular and biochemical techniques were used to follow cytokine, NGF and neuropeptide levels in hindpaw skin and sciatic nerves. Lumbar spinal cord Fos immunostaining was performed. Bone microarchitecture was measured using microcomputed tomography (microCT). We found that tibia fracture upregulated NGF expression in hindpaw skin and tibia bone along with sciatic nerve neuropeptide content. We also found nociceptive sensitization, enhanced spinal cord Fos expression, osteopenia and enhanced cytokine content of hindpaw skin on the side of the fracture. Anti-NGF treatment reduced neuropeptide levels in sciatic nerve and reduced nociceptive sensitization. There was less spinal cord Fos expression and bone loss in the anti-NGF treated animals. Conversely, anti-NGF did not decrease hindpaw edema, warmth or cytokine production. Collectively, anti-NGF reduced some but not all signs characteristic of CRPS illustrating the complexity of CRPS pathogenesis and NGF signaling.

Bone-density changes after stroke

It has been many years since bone loss and fracture risk were first recognized as serious complications of stroke. Hip fracture is associated with a substantial increase in morbidity and mortality for stroke survivors, and therefore, assessing and maintaining skeletal health after stroke should be an important clinical goal. Recent long-term, prospective studies have illustrated a highly nonuniform pattern of bone changes after stroke. In general, there is significant bone loss on the paretic side, which is greatest in those patients with the most severe functional deficits. In some patients, bone loss in the paretic arm during the first year after stroke is the equivalent of >20 yrs of bone loss in healthy individuals of comparable age. Bone density in the nonparetic upper limb can actually increase after stroke, consistent with an increase in habitual use of the nonparetic hand. Bone density in the paretic lower limb can decrease by >10% in <1 yr, with smaller decreases being typical for the nonparetic lower limb. Despite the recent increase in the number of prospective, longitudinal studies, important questions about bone changes after stroke remain unanswered. Longer-term studies quantifying bone loss for periods of >12 mos poststroke are needed to determine how long excess bone loss continues after stroke. Studies with more subjects and with more varied disability levels are needed to better understand the relationships between functional deficits and bone loss. New metrics are needed to quantify the intensity and duration of physical activity in the upper and lower limbs that are consistent with previous research on the role of mechanical stimuli in bone adaptation. Finally, an assessment of skeletal health and the factors that affect bone quantity and quality should be a standard component in the clinical management of all survivors of stroke.

A 19-week exercise program for people with chronic stroke enhances bone geometry at the tibia: a peripheral quantitative computed tomography study

BACKGROUND

We assessed the impact of a 19-week exercise program on bone health in chronic stroke.

RESULTS

Those who underwent the program reported significantly more gain in tibial trabecular bone content and cortical bone thickness on the affected side.

CONCLUSION

Regular exercise is thus beneficial for enhancing bone health in this population.

The relationship between bone mineral density and immobilization duration in hemiplegic limbs

OBJECTIVE

Prolonged immobilization in stroke is known to result in hypercalciuria, hypercalcemia, accelerated bone resorption, and osteoporosis. Furthermore, bone mineral loss accelerated with increasing duration of hemiplegia. Although stroke is a common disease that causes sudden immobilization, relatively few investigations of bone metabolism in stroke have been reported. The aim of this study was to investigate the changes in bone mineral density of the forearms and legs related to duration of hemiplegia-induced immobilization after stroke.

METHODS

Forty-one hemiplegic patients with stroke were evaluated. The patients' age, gender and duration of hemiplegia-induced immobilization were recorded. The measurements of bone mineral density (BMD) in all patients were evaluated with DEXA using the Norland apparatus. The BMD values (g/cm2) were determined by measurements made in the lumbar vertebrae, both forearm and legs (femoral neck and trochanter).

RESULTS

We found that bone mineral density was decreased in the affected extremities relative to the intact contralateral side on measurements by dual energy x-ray absorptiometry in bones such as forearm, femoral neck and trochanter. There was a significant difference between bone mineral density of paretic and nonparetic forearms and legs. Bone mineral density of the upper limbs was lower than that of the lower limbs. There was a negative correlation between duration of hemiplegia and BMD values.

CONCLUSIONS

Bone mineral loss may be related to the duration of hemiplegia-induced immobilization. Bone mineral loss is accelerated when the duration of hemiplegia is prolonged.

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

Following a stroke, the reduced level of physical activity and functional use of the paretic leg may lead to bone loss and muscle atrophy. These factors and the high incidence of falls may contribute to hip fractures in the stroke population. This study was the first to examine total proximal femur bone mineral content (BMC) and bone mineral density (BMD) and their relationship to stroke-specific impairments in ambulatory individuals with chronic stroke (onset >1 year). We utilized dual-energy X-ray absorptiometry (DXA) to acquire proximal femur and total body scans on 58 (23 women) community-dwelling individuals with chronic stroke. We reported total proximal femur BMC (g) and BMD (g/cm2) derived from the proximal femur scans, and lean mass (g) and fat mass (g) for each leg derived from the total body scans. Each subject was evaluated for ambulatory capacity (Six-Minute Walk Test), knee extension strength (hand-held dynamometry), physical fitness [maximal oxygen uptake (VO2max)] and spasticity (Modified Ashworth Scale). Results showed that the paretic leg had significantly lower proximal femur BMD, lean mass and percent lean mass, but higher fat mass than the non-paretic leg for both men and women. Proximal femur BMD of the paretic leg was significantly related to ambulatory capacity (r=0.33, P=0.011), muscle strength (r=0.39, P=0.002), physical fitness (r=0.57, P<0.001), but not related to spasticity (r=-0.23, P=0.080). Multiple regression analysis showed that lean mass in the paretic leg was a major predictor (r2=0.371, P<0.001) of the paretic proximal femur BMD. VO2max was a significant predictor of both paretic proximal femur BMD (r2=0.325, P<0.001) and lean mass in the paretic leg (r2=0.700, P<0.001). Further study is required to determine whether increasing physical fitness and lean mass are important to improve hip bone health in chronic stroke.

Fear of falling among stroke survivors after discharge from inpatient rehabilitation

The objectives of this study were to assess the incidence of falls and fall consequences among patients who were discharged from inpatient stroke rehabilitation and to investigate the proportion of those who experienced a fear of falling following a fall. This was a follow-up postal questionnaire study of patients who were admitted to the rehabilitation ward in a local hospital (Japan) for stroke rehabilitation. Seventy-three patients who met inclusion criteria were sent questionnaires and 49 (67%) responded to the questionnaire. Thirty-three patients had at least one fall after discharge from the hospital and of these, four patients experienced fractures resulting from their falls. Twenty-nine patients developed a fear of falling. As falls are common in stroke survivors, more attention should be paid to falls after stroke during inpatient rehabilitation to prevent physical and emotional consequences of falls.

Increased Bone Resorption in the Proximal Femur in Patients with Hemiplegia

OBJECTIVES

To investigate the relationship between the proximal femoral bone mineral density and bone resorption markers, determinants of calcium metabolism and vitamin D levels in elderly stroke patients.

DESIGN

A total of 80 patients and 20 controls were enrolled in the study. Bone mineral density measurements were obtained at the proximal femur. In all subjects, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, intact parathyroid hormone, osteocalcin, deoxypyridinoline, and ionized calcium concentrations were measured. Barthel Index and Motricity Index Leg Score were recorded all patients.

RESULTS

The serum concentrations of deoxypyridinoline, intact parathyroid hormone, and the mean serum ionized calcium levels were significantly higher in patients with stroke than that of the control subjects. The mean serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D concentrations in patients were significantly lower than those of the control group (P < 0.05). The bone mineral density of proximal femurs of paretic limbs was decreased significantly compared with those of the control group (P < 0.05). There were significant correlations between the Z score of the hemiplegic side and the patients' Barthel Index, Motricity Index Leg Score, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, calcium, and deoxypyridinoline.

CONCLUSIONS

This study provides clear evidence that decreased mobility, vitamin D status, and bone turnover variables in patients after stroke are important factors in the greater bone loss in the paretic leg.

Falls, fractures, and osteoporosis after stroke: time to think about protection?

BACKGROUND

Osteoporosis is a significant complication of stroke. The clinical course of hemiplegic stroke predisposes patients to disturbed bone physiology. Sudden immobility and unilateral loss of function unload the skeleton at key areas such as the affected hip. This is manifest by an early reduction in bone density at this site. Stroke patients may also have motor, sensory, and visual/perceptual deficits that predispose them to falls. These factors result in an early but sustained increase in hip fractures after stroke.

SUMMARY OF COMMENT

Potential bone loss is often overlooked in stroke treatment. Morbidity and mortality from hip fractures might be reduced by preventing bone loss at an early stage. In the crucial first year after stroke, bone loss seems to be due to accelerated resorption. Bisphosphonates are the drugs of choice in preventing osteoclastic bone resorption, but oral administration soon after stroke may be impractical. Potent new intravenous bisphosphonates have been used in postmenopausal women with osteoporosis with good preliminary results. Effective dosing regimens for osteoporosis have included a single annual or semiannual injection of bisphosphonate as well as weekly oral dosing. This article reviews the current literature on osteoporosis and hip fractures after stroke, making a case for a trial of intravenous bisphosphonates early after stroke.

CONCLUSIONS

Hip fracture after stroke is an increasingly recognized problem. Measures to prevent bone loss and preserve bone architecture have not been part of stroke management thus far. Because rapid bone loss is a risk factor for fracture, we believe that a randomized, placebo-controlled trial of intravenous bisphosphonates given in the early phase of stroke rehabilitation is indicated.

Relationships between physical activity and metacarpal cortical bone mass and bone resorption in hemiplegic patients

The aim of the present study was to investigate the relationships between physical activity and metacarpal cortical bone mineral density (BMD) and bone resorption in hemiplegic patients. Seventy-two male hemiplegic patients with cerebrovascular disease (mean age, 67.0 years; range 48-83 years) were recruited. Metacarpal cortical BMD in bilateral hands was measured by computed X-ray densitometry, and the levels of urinary cross-linked N-telopeptides of type I collagen (NTx), as a bone resorption marker, were measured by an enzyme-linked immunosorbent assay (ELISA). BMD (mean +/- SD) in the paralyzed hand was significantly lower than that in the nonparalyzed hand (2.52 +/- 0.46 and 2.64 +/- 0.45 mmAl; P < 0.05). On multiple regression analysis, BMD was significantly positively correlated with Brunnstrom stage (assessment of degree of paralysis) in the hand (P < 0.05), whereas urinary NTx levels were significantly negatively correlated with Brunnstrom stage in the hand, arm, and leg, and with walking ability (P < 0.05, P < 0.05, P < 0.01, and P < 0.01, respectively). These findings suggest that, in male hemiplegic patients, although metacarpal cortical BMD may be affected by only local physical activity, urinary NTx appears to be responsive to local and general physical activity.

Bone mineral density in patients with stroke

OBJECTIVE

Stroke is an acute neurologic dysfunction of vascular origin, characterized by loss of voluntary movement, sensory disturbances, and neurologic findings in the contralateral half of the body. Acute and long-term complications because of immobilization are seen in all organ systems. The aim of this study was to determine any differences between the affected and unaffected sides' bone mineral densities of acute and chronic stroke patients.

DESIGN

In this study, we determined the bone mineral densities (BMD) of 30 male patients with acute (0-20 days) and 30 male patients with chronic (6 months or longer) stroke and compared the densities with the normal side. Upper and lower limb BMDs were measured by dual-energy x-ray absorptiometry. Additionally, patients were evaluated for the degree of spasticity, the phases of motor improvement, and the activities of daily living.

RESULTS

In acute-phase stroke patients, BMD of the affected side was not significantly different from BMD of the normal side. BMD of both upper limbs of acute stroke patients was not different from normal side upper limb BMD of chronic stroke patients. In both acute and chronic stroke patients, affected and unaffected side lower limb BMDs (femur total BMD scores) were not significantly different. However, in chronic stroke patients, affected side BMD of Ward's region was significantly higher compared with the normal side. There is no correlation between BMD and Brunnstrom phases, Ashworth scales, and the degree of activities of daily living.

CONCLUSIONS

Higher BMD of the affected side Ward's region in chronic cerebrovascular accident patients may be related to spasticity and changes in walking pattern, which increase the mechanical stress loading of the Ward's region.

Prevention of secondary osteoporosis postmenopause in hemiplegia

OBJECTIVES

To study secondary osteoporosis postmenopause in women with hemiplegia and to show the therapeutic effects of etidronate and how osteoporotic conditions relate to the activities of daily living (ADL).

DESIGN

Eighty-one postmenopausal women with hemiplegia were admitted within 6 mo of their first cerebrovascular accident. The bone mineral density (BMD) and biochemical markers of bone turnover were measured at the time of admission. Forty women (treatment group) received a 2-wk administration of etidronate. Forty-one women (control group) were not administered etidronate.

RESULTS

After completing a 3-mo rehabilitation program, BMD levels were remeasured. ADL was evaluated by FIM. The low ADL group had a larger decrease in BMD than the high ADL group. For the control group, the BMD rate of change on the paretic side of the femoral neck was -9.6%/3 mo for the low ADL group. BMD loss was reduced significantly by the administration of etidronate for the low ADL group.

CONCLUSIONS

Results indicate that ADL corresponds to the progression of osteoporosis in postmenopausal women with hemiplegia and that increasing the level of ADL will reduce the progression of osteoporosis. Use of etidronate has also been proven to have a suppressive effect on the BMD decrease in women.

Forearm bone mineral density by age in 7,620 men and women: the Tromsø study, a population-based study

Population-based studies of adult forearm bone mineral density (BMD) by age are scarce, and standardized reference values are lacking. In this cross-sectional study, men aged 55-74 years, women aged 50-74 years, and representative 5-10% samples of remaining age groups between 25 and 84 years living in Tromsø, Norway, were invited for forearm BMD measurement in 1994-1995. The authors measured 3,062 men and 4,558 women (response rate, 78%) by single x-ray absoptiometry at distal and ultradistal forearm sites. Up to age 50, the mean BMD difference was -0.1% per 1-year age group in both sexes. After age 50, the mean BMD difference per 1-year age group was -0.6% in men and -1.3% (distal) and -1.5% (ultradistal) in women. The BMD by age curve was linear for men throughout senescence, but women had a slope change to -0.7% (distal) and -0.8% (ultradistal) per 1-year age group from the 65- to 69-year age group. BMD levels and BMD by age association in the general population (n = 7,620) and in the population without bone-threatening diseases or medication (n = 5,179) were similar. Only longitudinal studies can clarify whether cohort effects or longitudinal BMD development patterns explain these cross-sectional results.

Abnormal bone and calcium metabolism in patients after stroke

OBJECTIVE

To review how mineral stores and endocrine factors affect bone mass in poststroke patients immobilized by hemiparesis.

DATA SOURCES

Computer databases and published indexes.

STUDY SELECTION

Case-control studies of hemiparetic poststroke patients examined regarding bone metabolism.

DATA EXTRACTION

References were obtained from MEDLINE; all data concerning the objective were used.

DATA SYNTHESIS

Bone loss occurs in affected extremities after stroke. Immobilization from hemiplegia causes hypercalcemia. Insufficiency or deficiency of 25-hydroxyvitamin D (25-OHD) is very common in stroke patients and may be caused by poor dietary intake, decreased sunlight exposure, or both. Compensatory hyperparathyroidism may not occur because hypercalcemia inhibits the parathyroid glands even when 25-OHD is in the insufficient range. However, hyperparathyroidism does occur when 25-OHD is in the deficient range, in which case the parathyroid response to hypovitaminosis D overrides effects of hypercalcemia. Increased bone resorption was observed during the first year after stroke, declining to normal during the second year. During the first year, determinants of bone mineral density (BMD) in hands affected by hemiplegia were age, severity of hemiplegia, duration of paralysis, serum calcium concentration, and 25-OHD concentration. In the second year, BMD determinants on the hemiplegic side were severity of hemiplegia and 25-OHD concentration, whereas 25-OHD concentration was the only BMD determinant on the intact side. Administering 1alpha-hydroxyvitamin D3, vitamin K2, or ipriflavone ameliorated osteopenia on both sides and decreased the frequency of hip fracture on the hemiplegic side.

CONCLUSIONS

Bone remodeling and determinants of bone mass for the affected and unaffected sides after stroke differ between the first and subsequent years.

Osteoporosis in hemiplegic stroke patients as studied with dual-energy X-ray absorptiometry

OBJECTIVES

To compare bone mineral densities (BMDs) of the affected and unaffected limbs in stroke patients at multiple sites; to study longitudinal changes during a 3-month rehabilitation program; and to relate BMDs to demographic, impairment, and disability variables.

DESIGN

Descriptive study.

SETTING

Tertiary rehabilitation center.

PATIENTS

One hundred four consecutive hemiplegic inpatients, 69 men, age 56.5 +/- 13.2 yrs, 47 with left-sided brain lesion. Median days from onset to admission and median length of stay days were 83 and 105.5, respectively.

MAIN OUTCOME MEASURES

BMDs of proximal humerus, distal radius, femoral neck, and calcaneus bilaterally, and third lumbar vertebra, measured with dual-energy x-ray absorptiometry (DXA), were compared between affected and unaffected sides at admission and discharge.

RESULTS

Stroke Impairment Assessment Set (SIAS) motor scores, Functional Independence Measure (FIM) scores, grip strength, and awake/sleep heart rate counts (activity index) improved significantly at discharge. Affected/unaffected BMD ratios were 88.3% to 98.4% at admission and 79.6% to 98.8% at discharge, lowest for the humerus. Discharge/admission ratios were 89.1% to 97.8% for the affected and 97.4% to 100% for the unaffected side. All BMDs were intercorrelated (R = .438 to .873). They correlated significantly with age, body weight, grip strength, FIM scores, and activity index. Factors selected to explain BMD with multiple regression analysis differed according to the site and timing of the measurement.

CONCLUSIONS

BMDs of the affected side were lower and most marked in the humerus. Longitudinally, not only the affected but the unaffected BMDs decreased. Age, sex, duration of stroke, anthropometric measurements, motor paralysis, muscle strength, and activity level contributed differently to bone loss according to the site and timing of the measurement.

Effect of calcitonin on bone and connective tissue metabolism in hemiplegic patients: a two-year prospective study

OBJECTIVES

To test the effects of 200 IU/day of a nasal spray of salmon calcitonin in modulating the increased bone tissue metabolism observed in hemiplegic patients.

DESIGN

A two-year, prospective, randomized, double-blind, placebo-controlled study.

PATIENTS

Thirty-four patients with hemiplegia due to a cerebrovascular accident were included in the study during the first month after onset of hemiplegia after giving their informed consent. All patients followed a suitably planned course of active rehabilitation according to Bobath. They were randomly allocated to either the calcitonin or the placebo group but all of them received a daily oral calcium supplementation of 1000 mg.

RESULTS

Biochemical markers of bone formation, serum total alkaline phosphatase, osteocalcin and type I procollagen did not vary during the two years of follow-up. Cross-linked carboxy-terminal telopeptide of type I collagen, a biochemical marker of bone resorption, was elevated initially after stroke and then decreased significantly (p <0.001), stabilizing as of month 12. Urinary calcium/creatinine and total hydroxyproline/creatinine ratios presented with similar profiles. The serum levels of the type III procollagen, a marker of connective tissue metabolism, were also elevated upon entry and decreased thereafter. No significant difference could be found between the calcitonin-treated and the placebo group for any of the biochemical markers at any time point.

CONCLUSION

This prospective study demonstrated that biochemical markers of bone and connective tissue metabolism were elevated shortly after the occurrence of stroke and then gradually decreased during the first two years after injury. The daily administration of 200 IU of intranasal calcitonin did not influence the levels of these markers.

Bone mineral density of metatarsus in hemiplegic subjects

The cortical bone mineral density (BMD) of the first metatarsus was measured using computed x-ray densitometry in 84 hemiplegic subjects (35 men and 49 postmenopausal women) and 49 healthy age-matched controls (23 men and 26 postmenopausal women), and the determinants of paralysis-induced cortical osteopenia were investigated. In the hemiplegia group, ages were 63.9 +/- 9.8 yr (mean +/- standard deviation) for men and 66.6 +/- 11.0 yr for women. The duration of hemiplegia was 25.3 +/- 19.8 mo for men and 26.0 +/- 26.3 mo for women. The Brunnstrom stage (lower limb) was 4.0 +/- 1.1 for men and 3.8 +/- 1.4 for women. The walking ability, evaluated by walking score, was 3.6 +/- 1.3 (range, 1-5) for men and 3.2 +/- 1.5 (range, 1-5) for women. The time since menopause was 14.8 +/- 10.0 yr. The age and time since menopause were similar in the hemiplegia and control groups. On the paralyzed side, the BMD of men and women in the hemiplegia group was significantly lower than that of the control group on the nondominant side (by 6.1% and 11.6%, respectively). In hemiplegic men, Brunnstrom stage and walking score showed a significant positive correlation to the BMD (r = 0.418 and r = 0.349, respectively). In hemiplegic women, on the other hand, age, duration of hemiplegia, and years since menopause showed a significant negative correlation to the BMD (r = -0.260, r = -0.478, and r = -0.506, respectively), and Brunnstrom stage and walking score showed a significant positive correlation to the BMD (r = 0.526 and r = 0.406, respectively). These findings suggest that the determinant of metatarsal cortical BMD loss on the paralyzed side of the hemiplegic subject might be different according to gender. That is, although the degree of paralysis and walking ability could be a determinant of metatarsal cortical BMD loss on the paralyzed side of hemiplegic men, additional factors such as age, duration of hemiplegia, and years since menopause could play an important role in the determination of metatarsal cortical BMD loss in postmenopausal hemiplegic women.