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

The pathogenesis of post-stroke osteoporosis and the role oxidative stress plays in its development

Cardiovascular disease and osteoporotic fractures (OF) are the main diseases affecting the health of middle-aged and elderly people. With the gradual increase of population aging in China and even the world, the incidence of the two and the prevalence of high-risk groups are also showing a continuous upward trend. The relationship between the two, especially the impact of cardiovascular disease on the risk and prognosis of OF, has attracted more and more attention. Therefore, it is of great significance to fully understand the pathogenesis of cardiovascular and cerebrovascular diseases and the resulting osteoporosis and to provide targeted interventions to prevent the occurrence of diseases and fractures. This article reviews the relationship between one of the Cardiovascular disease-stroke and related therapeutic drugs and the risk of OF, and the role of oxidative stress in its pathophysiological mechanism by reviewing relevant domestic and foreign literature in recent years, in order to gain a more comprehensive understanding of the association between stroke and OF, and then provide a basis and reference for screening high-risk groups of fractures and reducing the burden on the health system caused by the disease.

Impact of Osteoporosis Pharmacotherapy on Functional Outcomes after Ischemic Stroke

This study evaluated whether osteoporosis pharmacotherapy (OPT) affected functional outcomes in acute ischemic stroke patients with osteoporosis. Using a single-center registry database, we consecutively registered acute ischemic stroke patients between May 2016 and December 2020. All patients older than 55 years underwent routine bone densitometry within 7 days of stroke onset. OPT prescription was confirmed by reviewing medical records. We classified the patients into OPT and no OPT groups. We performed propensity score matching (PSM) to overcome the imbalance in multiple covariates between the two groups. We investigated whether OPT affected 1-year functional outcomes by multivariate analysis using a PSM cohort. Among 1307 consecutively registered acute ischemic stroke patients, 381 patients were enrolled in this study, of whom 134 (35.2%) were prescribed OPT at discharge, which was maintained for 1 year. In a multivariate analysis using a PSM cohort, the OPT group had a lower risk of dependency (odds ratio [OR], 0.52; 95% confidence interval [CI], 0.27-0.996) and poor functional outcome at 1 year (OR, 0.24; 95% CI, 0.10-0.57). The OPT group also had increased chance of late functional improvement (OR, 6.16; 95% CI, 1.12-33.79). This study showed that OPT could reduce dependency and poor functional outcomes and increase the chance of improving functional outcomes at 3 months and 1 year after ischemic stroke onset, and these findings could be helpful for improving functional outcomes and bone health after ischemic stroke.

Comparison of Fractures Among Older Adults Who Are Ambulatory vs Those Who Use Wheelchairs in Sweden

IMPORTANCE

Several diseases and conditions, such as cerebrovascular disease, arthritis, previous fractures, neurological diseases, or amputation, can result in severe immobility justifying wheelchair use for increased mobility. Immobility results in disuse osteoporosis and is considered a risk factor for fracture, although there are no large cohort studies that have investigated fracture risk in patients who use wheelchairs compared with an ambulatory control group.

OBJECTIVE

To investigate whether immobilized adults who used wheelchairs had a different risk of fracture and injurious falls compared with matched ambulatory controls.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study compared patients who used wheelchairs and controls (propensity score matched 1:1 using 22 variables relating to anthropometrics, general condition, comorbidity, and fall and fracture risk), identified through a national database of adults 65 years or older who underwent a health evaluation (baseline) at Swedish health care facilities. Patients were followed up from January 1, 2007, to December 31, 2017, and data analysis was performed between June 1 and 30, 2022.

MAIN OUTCOMES AND MEASURES

Incident fracture, injurious falls without fracture, and deaths.

RESULTS

A total of 55 442 adults using wheelchairs were included in the analysis (mean [SD] age, 83.2 [8.3] years; 60.5% women). Those who used wheelchairs and the 55 442 matched controls were followed up for a median of 2.0 (IQR, 0.5-3.2) and 2.3 (IQR, 0.8-3.6) years, respectively. Patients who used wheelchairs had a lower risk of any fracture (hazard ratio [HR], 0.43 [95% CI, 0.41-0.44]), major osteoporotic fracture (HR, 0.32 [95% CI, 0.31-0.33]), and hip fracture (HR, 0.30 [95% CI, 0.28-0.32]) compared with the ambulatory controls, associations that were only marginally affected by multivariable (same as the matching variables) adjustment. The risk of fall injury was lower among those who used wheelchairs than among ambulatory controls (unadjusted HR for Cox proportional hazards models, 0.48 [95% CI, 0.47-0.50]) and remained highly similar after adjustments. Patients who used wheelchairs had a significantly increased risk of death (HR, 1.35 [95% CI, 1.33-1.36]) compared with controls. Association between wheelchair use and fracture outcomes and injurious falls, calculated using a Fine and Gray model with death as a competing risk, was similar to associations obtained using Cox proportional hazards regression for all fracture outcomes.

CONCLUSIONS AND RELEVANCE

In this retrospective cohort study of older adults, wheelchair use was associated with a lower risk of fracture than observed in ambulatory controls. These findings suggest that immobility associated with wheelchair use should not be considered a risk factor for fracture.

Approach to patients with hip fracture and concurrent stroke

We report a case of a 70-year-old man who presented with concomitant hip fracture and stroke. Our patient underwent surgical correction of a hip fracture despite the increased perioperative and postoperative risks associated with an acute stroke. He achieved good functional outcome after surgery and subsequent rehabilitation. There are no clear guidelines on the factors to determine whether a patient with concomitant stroke and hip fracture is a good candidate for surgical hip repair. Furthermore, there is also no consensus on the appropriate timing of surgical repair for such patients. We postulate that factors such as functional status, comorbidities, type and severity of stroke will affect the decision to proceed with surgical repair, and that there is a benefit in advocating for surgery in appropriate patients by a multidisciplinary orthogeriatric care team.

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.

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.

Vitamin D and Rehabilitation after Stroke: Status of Art

Stroke is the first cause of disability in the population and post-stroke patients admitted to rehabilitation units often present a malnutrition status which can influence nutritional indices and then vitamin levels. Vitamin D deficiency seems implicated beyond stroke severity and stroke risk, and also affects post-stroke recovery. Some studies on vitamin D levels and outcome in stroke patients are available but very few data on vitamin D levels and outcome after rehabilitation treatment are reported. This literature review shows the possible relationship between vitamin D deficiency and recovery in post-stroke patients undergoing rehabilitation treatment. Moreover, because several studies have reported that single nucleotide polymorphisms and promoter methylation in genes are involved in vitamin D metabolism and might affect circulating vitamin D levels, these aspects are evaluated in the current paper. From the studies evaluated in this review, it emerges that vitamin D deficiency could not only have an important role in the recovery of patients undergoing rehabilitation after a stroke, but that genetic and epigenetic factors related to vitamin D levels could have a crucial role on the rehabilitation outcome of patients after stroke. Therefore, further studies are necessary on stroke patients undergoing rehabilitation treatment, including: (a) the measurement of the 25(OH) vitamin D serum concentrations at admission and post rehabilitation treatment; (b) the identification of the presence/absence of CYP2R1, CYP27B1, CYP24A1 and VDR polymorphisms, and (c) analysis of the methylation levels of these genes pre- and post-rehabilitation treatment.

An investigation into the impact and implications of published papers from retracted research: systematic search of affected literature

OBJECTIVE

Analyses of the impact of a body of clinical trial reports subject to research misconduct have been few. Our objective was to examine the impact on clinically relevant research of a group of researchers' trial reports ('affected trial reports') affected by research misconduct, and whether identification of misconduct invoked a reappraisal.

DESIGN

In 2016, we used five databases and search engines to identify 'citing publications', that is, guidelines, systematic and other reviews, and clinical trials citing any of 12 affected trial reports, published 1998-2011, eventually retracted for research misconduct. The affected trial reports were assessed more likely to have had impact because they had hip fracture outcomes and were in journals with impact factor >4. Two authors assessed whether findings of the citing publications would change if the affected trial reports were removed. In 2018, we searched for evidence that the citing publications had undertaken a reassessment as a result of the potential influence of the affected trial reports.

RESULTS

By 2016 the affected trial reports were cited in 1158 publications, including 68 systematic reviews, meta-analyses, narrative reviews, guidelines and clinical trials. We judged that 13 guidelines, systematic or other reviews would likely change their findings if the affected trial reports were removed, and in another eight it was unclear if findings would change. By 2018, only one of the 68 citing publications, a systematic review, appeared to have undertaken a reassessment, which led to a correction.

CONCLUSIONS

We found evidence that this group of affected trial reports distorted the evidence base. Correction of these distortions is slow, uncoordinated and inconsistent. Unless there is a rapid, systematic, coordinated approach by bibliographic databases, authors, journals and publishers to mitigate the impact of known cases of research misconduct, patients, other researchers and their funders may continue to be adversely affected.

Risk of fractures after stroke: Results from the Ontario Stroke Registry

OBJECTIVE

To determine the risk of fractures after stroke.

METHODS

Using the Ontario Stroke Registry, we identified a population-based sample of consecutive patients seen in the emergency department or hospitalized with stroke (n = 23,751) or TIA (n = 11,240) at any of 11 stroke centers in Ontario, Canada, and discharged alive between July 1, 2003, and March 31, 2012. We compared the risk of low-trauma fractures in patients with stroke vs those with TIA using propensity score methods to adjust for differences in baseline factors. Secondary analyses compared fracture risk poststroke with that in age-/sex-matched controls without stroke or TIA (n = 23,751) identified from the Ontario Registered Persons Database.

RESULTS

The 2-year rate of fracture was 5.7% in those with stroke compared to 4.8% in those with TIA (adjusted cause-specific hazard ratio [aHR] for those with stroke vs TIA 1.32; 95% confidence interval [CI] 1.19-1.46) and 4.1% in age-/sex-matched controls (aHR for those with stroke vs controls 1.47; 95% CI 1.35-1.60). In the cohort with stroke, factors associated with fractures were older age, female sex, moderate stroke severity, prior fractures or falls, and preexisting osteoporosis, rheumatoid arthritis, hyperparathyroidism, and atrial fibrillation.

CONCLUSIONS

Stroke is associated with an increased risk of low-trauma fractures. Individuals with stroke and additional risk factors for fractures may benefit from targeted screening for low bone mineral density and initiation of treatment for fracture prevention.

Mechanotransduction in bone: Intervening in health and disease

Mechanotransduction has been proven to be one of the most significant variables in bone remodeling and its alterations have been shown to result in a variety of bone diseases. Osteoporosis, Paget’s disease, orthopedic disorders, osteopetrosis as well as hyperparathyroidism and hyperthyroidism all comprise conditions which have been linked with deregulated bone remodeling. Although the significance of mechanotransduction for bone health and disease is unquestionable, the mechanisms behind this important process have not been fully understood. This review will discuss the molecules that have been found to be implicated in mechanotransduction, as well as the mechanisms underlying bone health and disease, emphasizing on what is already known as well as new molecules potentially taking part in conveying mechanical signals from the cell surface towards the nucleus under physiological or pathologic conditions. It will also focus on the model systems currently used in mechanotransduction studies, like osteoblast-like cells as well as three-dimensional constructs and their applications among others. It will also examine the role of mechanostimulatory techniques in preventing and treating bone degenerative diseases and consider their applications in osteoporosis, craniofacial development, skeletal deregulations, fracture treatment, neurologic injuries following stroke or spinal cord injury, dentistry, hearing problems and bone implant integration in the near future.

Poststroke hip fracture: prevalence, clinical characteristics, mineral-bone metabolism, outcomes, and gaps in prevention

Objective. To assess the prevalence, clinical and laboratory characteristics, and short-term outcomes of poststroke hip fracture (HF). Methods. A cross-sectional study of 761 consecutive patients aged ≥60 years (82.3 ± 8.8 years; 75% females) with osteoporotic HF. Results. The prevalence of poststroke HF was 13.1% occurring on average 2.4 years after the stroke. The poststroke group compared to the rest of the cohort had a higher proportion of women, subjects with dementia, history of TIA, hypertension, coronary artery disease, secondary hyperparathyroidism, higher serum vitamin B12 levels (>350 pmol/L), walking aid users, and living in residential care facilities. The majority of poststroke HF patients had vitamin D insufficiency (68%) and excess bone resorption (90%). This group had a 3-fold higher incidence of postoperative myocardial injury and need for institutionalisation. In multivariate analysis, independent indicators of poststroke HF were female sex (OR 3.6), history of TIA (OR 5.2), dementia (OR 4.1), hypertension (OR 3.2), use of walking aid (OR 2.5), and higher vitamin B12 level (OR 2.3). Only 15% of poststroke patients received antiosteoporotic therapy prior to HF. Conclusions. Approximately one in seven HFs occurs in older stroke survivors and are associated with poorer outcomes. Early implementation of fracture prevention strategies is needed.

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.

Mechanical factors and bone health: effects of weightlessness and neurologic injury

Bone is a dynamic tissue with homeostasis governed by many factors. Among them, mechanical stimuli appear to be particularly critical for bone structure and strength. With removal of mechanical stimuli, a profound bone loss occurs, as best observed in the extreme examples following exposure to space flight or neurologic impairment. This review provides an overview of the changes in bone density and structure that occur during and after space flight as well as following neurologic injury from stroke and spinal cord injury. It also discusses the potential mechanisms through which mechanical stimuli are postulated to act on bone tissue.

Physical fitness training for stroke patients

BACKGROUND

Physical fitness is low after stroke. It is unknown whether improving physical fitness after stroke reduces disability.

OBJECTIVES

To determine whether fitness training (cardiorespiratory or strength, or both) after stroke reduces death, dependence and disability. The secondary aims were to determine the effects of fitness training on physical fitness, mobility, physical function, health status and quality of life, mood and incidence of adverse events.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched March 2009), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2007), MEDLINE (1966 to March 2007), EMBASE (1980 to March 2007), CINAHL (1982 to March 2007), and six additional databases to March 2007. We handsearched relevant journals and conference proceedings, and screened bibliographies. We searched trials registers and contacted experts in the field.

SELECTION CRITERIA

We included randomised controlled trials if the aim of the intervention was to improve muscle strength or cardiorespiratory fitness, or both, and if the control groups comprised either no intervention, usual care or a non-exercise intervention.

DATA COLLECTION AND ANALYSIS

Two review authors determined trial eligibility and quality. One review author extracted outcome data at end of intervention and follow-up scores, or as change from baseline scores. Diverse outcome measures limited the intended analysis.

MAIN RESULTS

We included 24 trials, involving 1147 participants, comprising cardiorespiratory (11 trials, 692 participants), strength (four trials, 158 participants) and mixed training interventions (nine trials, 360 participants). Death was infrequent at the end of the intervention (1/1147) and follow up (8/627). No dependence data were reported. Diverse disability measures made meta-analysis difficult; the majority of effect sizes were not significant. Cardiorespiratory training involving walking, improved maximum walking speed (mean difference (MD) 6.47 metres per minute, 95% confidence interval (CI) 2.37 to 10.57), walking endurance (MD 38.9 metres per six minutes, 95% CI 14.3 to 63.5), and reduced dependence during walking (Functional Ambulation Categories MD 0.72, 95% CI 0.46 to 0.98). Current data include few strength training trials, and lack non-exercise attention controls, long-term training and follow up.

AUTHORS' CONCLUSIONS

The effects of training on death, dependence and disability after stroke are unclear. There is sufficient evidence to incorporate cardiorespiratory training, involving walking, within post-stroke rehabilitation in order to improve speed, tolerance and independence during walking. Further trials are needed to determine the optimal exercise prescription after stroke and identify any long-term benefits.

Bone health in stroke

In 2004 the Stroke Association stated ‘Each year over 130,000 people in England and Wales have a stroke. Of all people who suffer from a stroke, about a third are likely to die within the first 10 days, about a third are likely to make a recovery within one month and about a third are likely to be left disabled and needing rehabilitation. Stroke has a greater disability impact than any other medical condition. A quarter of a million people are living with long-term disability as a result of stroke in the UK.’