Accelerated bone remodeling in patients with poststroke hemiplegia

Osteocalcin improves outcome after acute ischemic stroke

Background: Osteocalcin is related to energy metabolism, memory and the acute stress response, suggesting a relationship between bone and the brain. The need to explore the effect of osteocalcin on acute ischemic stroke is therefore urgent.

Results: Patients with better outcomes had higher serum osteocalcin levels than those whose NIHSS scores did not improve. Multivariable logistic regression analysis showed acceptable performance (area under the curve = 0.766). The effect of osteocalcin on the promotion of neuron survival was confirmed by Cell Counting Kit-8 experiments. In addition, osteocalcin could decrease proline hydroxylase 1 and inhibit the degradation of gasdermin D.

Conclusions: We propose that osteocalcin can improve outcome after acute ischemic stroke in the acute period. By downregulating proline hydroxylase 1, osteocalcin leads glucose metabolism to the pentose phosphate pathway and therefore promotes neuronal survival through inhibiting pyroptosis.

Methods: Demographic data and laboratory results were obtained from patients with ischemic stroke in the acute period for analysis. A receiver operating characteristic curve was used to assess the discrimination of the prediction model. The potential effect of osteocalcin on cerebral ischemia and osteocalcin mechanism were explored in cultured primary rat cerebral cortical neurons treated with oxygen-glucose deprivation and reoxygenation.

FUNCTION AND BIOMECHANICS OF UPPER LIMB IN POST-STROKE PATIENTS — A SYSTEMATIC REVIEW

Current clinical services are struggling to provide the most favorable rehabilitation treatment for patients with stroke, which inspired researchers to investigate and explore the use of rehabilitation devices suitable for the patients and rehabilitation therapy. This review paper addresses the importance of biomechanical features in patients who experienced stroke to the upper limb. First and foremost, a review was done on general biomechanical description associated with motor control, shoulder, elbow, wrist and fingers joint. This included the ability of the patients to move their affected arm and the affect on peak joint torque, range of motion, joint forces, grip strength and muscle activities during the activities of daily living. In addition, we also reviewed the material properties and geometrical condition of tissue in stroke patient. The repercussions of post-stroke patient regarding the bone density, stiffness of muscle as well as the thickness of cartilage are described in this review. Based on the findings, the movement of affected stroke hand is associated with the motor control and material properties of tissue. To strengthen the motor control and maintaining tissue properties, early physical training on patients should be conducted in two to four weeks after stroke. In conclusion, this report suggests a new approach for future biomechanical studies in order to enhance the quality of physiotherapy rehabilitation peculiarly for post-stroke patients.

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.

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.

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.

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.

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.

Longitudinal study of bone and calcium metabolism and fracture incidence in spinocerebellar degeneration

Little is known about bone and calcium metabolism and fracture incidence in spinocerebellar degeneration (SCD) despite frequent falls and immobilization. To address bone and calcium metabolism and fracture incidence in SCD, we conducted a 10-year prospective study in a cohort of adult patients with SCD. Bone mineral density (BMD) and serum levels of ionized calcium, parathyroid hormone, 25-hydroxyvitamin D, and pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP) were followed in 110 patients with SCD for 10 years. Age-matched healthy volunteers (n = 110) served as controls. At baseline, the SCD patients had a low BMD with high levels of serum ionized calcium and ICTP which correlated with the degree of immobilization (Barthel index). Over 10 years, serum 25-hydroxyvitamin D decreased to the osteomalacic level (<5 ng/ml), and calcium and ICTP further increased in accordance with a decreased Barthel index score. The BMD decreased by 15.2% in men and by 24.6% in women. The incidence of fractures in the patients was significantly higher as compared with the control group (men 8/49 vs. 1/42, p = 0.0428; women 16/49 vs. 2/48, p = 0.0026). Over 10 years, the BMD was significantly reduced in the SCD patients, particularly in women, which increased the risk of a fracture. Vitamin D deficiency due to sunlight deprivation, increased bone resorption due to immobilization, and frequent falls are probable causes of osteoporosis and fractures in these patients. Hypovitaminosis D and increased bone resorption may be corrected readily by the routine use of vitamin D supplements together with bisphosphonate.

Effect of surgical treatment on physical activity and bone resorption in patients with neurogenic intermittent claudication

The effect of surgical treatment on physical activity and bone resorption was examined in patients with neurogenic intermittent claudication. Nineteen patients, 50-77 years of age, with neurogenic intermittent claudication (mean, 162 m; range, 20-400 m) caused by degenerative lumbar disease were included in the study. Decompressive laminectomy alone was performed for 7 patients with lumbar spinal stenosis (LSS) and 5 patients with degenerative lumbar spondylolisthesis (DLSL), and decompressive laminectomy, with a Graf stabilization system, was performed for 7 patients with DLSL associated with flexion instability. Clinical symptoms and levels of urinary cross-linked N-telopeptides of type I collagen (NTx) were assessed before and 12 months after surgery. Subjective symptoms, including low back pain, leg pain and/or tingling, and gait disturbance, as well as restriction of activities of daily living were significantly alleviated by the surgical treatment, resulting in an increase in physical activity. Urinary NTx levels were significantly decreased by the surgical treatment, from 63.1 +/- 16.9 (mean +/- SD) nmol BCE/mmol Cr to 52.1 +/-11.2 nmol BCE/mmol Cr (P < 0.05). These findings suggest that surgical treatment appears to alleviate the clinical symptoms and increase physical activity in patients with LSS or DLSL, potentially resulting in the suppression of bone resorption. Surgical treatment may contribute to the prevention of physical inactivity-induced osteoporosis in elderly patients with neurogenic intermittent claudication caused by degenerative lumbar disease.

Effect of administration of lipoprostaglandin E(1) on physical activity and bone resorption in patients with neurogenic intermittent claudication

The effect of the systemic administration of prostaglandin (PG) E(1) on physical activity and bone resorption was examined in patients with intermittent claudication (gait disturbance). Twenty male patients (age, 67.2 +/- 7.8 years; mean +/- SD) with neurogenic intermittent claudication caused by lumbar spinal canal stenosis were included in the study. Lipo-PG E(1) was administered intravenously, at a daily dose of 10 microg, on 3 days a week, for 6 months in all patients. Clinical symptoms, levels of urinary cross-linked N-telopeptides of type I collagen (NTx), and metacarpal cortical bone mineral density (BMD) were assessed before and just after the 6 months of treatment. Subjective symptoms, including leg pain and/or tingling and gait disturbance, and restrictions of the activities of daily living were significantly improved. However, no significant changes were observed in either urinary NTx levels or metacarpal cortical BMD. These findings suggest that the systemic administration of PG E(1) appears to improve subjective symptoms and activities of daily living in elderly male patients with neurogenic intermittent claudication, but does not affect either bone resorption or metacarpal cortical BMD. Short-term systemic administration of PG E(1) and increased physical activity in elderly male patients with gait disturbance caused by lumbar spinal canal stenosis may not affect bone resorption.

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.

Serum beta2-microglobulin reflects increased bone resorption in immobilized stroke patients

OBJECTIVE

The so-called bone-derived growth factor, beta2-microglobulin, has a regulatory function in bone metabolism by stimulating osteoclast activity. We undertook this study because osteoclast activity is known to be enhanced in patients with immobilized stroke, suggesting that their beta2-microglobulin concentrations may be increased.

DESIGN

We studied 79 patients with acute stroke hemiplegia, including 36 men and 43 postmenopausal women ranging in age between 51 and 70 yr.

RESULTS

The mean Barthel Index was 43 and 42 for men and women, respectively. The serum beta2-microglobulin concentration was increased in male and female patients, compared with the findings of 44 age-matched control subjects, and the serum concentration of pyridinoline cross-linked carboxyterminal telopeptide of type 1 collagen was also increased in male and female patients, compared with the findings of the control subjects. Serum concentrations of pyridinoline cross-linked carboxyterminal telopeptide of type 1 collagen correlated negatively with Barthel Index scores in both genders, indicating increased bone resorption caused by immobilization in these patients. Linear regression analysis revealed a positive correlation between beta2-microglobulin and pyridinoline cross-linked carboxyterminal telopeptide of type 1 collagen in both genders.

CONCLUSIONS

These findings suggest that beta2-microglobulin reflects osteoclastic activity in response to stroke-induced immobilization in both genders. Beta2-microglobulin is a useful indicator of bone resorption in patients with immobilized stroke.

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.

Effect of ipriflavone on bone in elderly hemiplegic stroke patients with hypovitaminosis D

A significant reduction in bone mineral density occurs in stroke patients on the hemiplegic side, correlating with the degree of paralysis and vitamin D deficiency due to malnutrition, sunlight deprivation, and immobilization-induced hypercalcemia, and increases the risk of hip fracture. We evaluated the effect of ipriflavone and 1alpha-hydroxyvitamin D3 [1alpha(OH)D3; vitamin D3] administration on bone mineral density preservation as compared with untreated controls. In a randomized and prospective study of 103 patients with hemiplegia after stroke (the mean duration of illness was 4.8 yr), 68 (34 patients in each group) were given 600 mg ipriflavone or 1 microg vitamin D3 daily for 12 mo, whereas the remaining 35 patients received no drug. Bone mineral density on the hemiplegic side decreased by 1.4% in the ipriflavone group, 3.8% in the vitamin D3 group, and 5.4% in the control group (P < .0001, ipriflavone v vitamin D3 and control). At baseline, all three groups of patients showed a 25-hydroxyvitamin D insufficiency, increased serum ionized calcium, and low levels of 1, 25-dihydroxyvitamin D, suggesting immobilization-induced hypercalcemia and inhibition of renal synthesis of 1, 25-dihydroxyvitamin D. After treatment, the serum 1, 25-dihydroxyvitamin D level increased by 139.9% in the ipriflavone group and by 26.9% in the vitamin D3 group. Significant decreases in the serum ionized calcium and pyridinoline cross-linked carboxyterminal telopeptide of type I collagen, and increases in parathyroid hormone and bone Gla protein were observed in the ipriflavone group, whereas no changes occurred in the other two groups. One patient in the untreated group suffered a hip fracture, compared with none in the ipriflavone and vitamin D3 groups. These results suggest that ipriflavone is more efficacious than vitamin D3 in the prevention of decreased bone mineral density in hemiplegic stroke patients because it decreases serum calcium levels through inhibition of bone resorption and cause a subsequent increase in 1, 25-dihydroxyvitamin D concentration.

Vitamin K deficiency and osteopenia in disuse-affected limbs of vitamin D-deficient elderly stroke patients

Bone mineral density is reduced in stroke patients on the hemiplegic and contralateral sides, reflecting a degree of paralysis and vitamin D deficiency. Because the deficiency of vitamin K, a factor essential for site-specific carboxylation of bone Gla protein, is also associated with reduced bone mineral density, an additional contribution of vitamin K to bone changes was assessed in 168 elderly patients with long-standing post-stroke hemiplegia and hypovitaminosis D. Sera were analyzed to relate vitamin K1 concentrations to bone-related biochemical indexes and bone mineral density measured by radiodensitometry of the second metacarpal. Bone mineral density was lower on both sides in patients than in the 56 controls (P < 0.02). Serum vitamin K1 concentrations, which correlated positively with bone Gla protein concentrations (P < 0.0001), were lower in patients (0.48 +/- 0.47 nmol/L) than controls (1.33 +/- 0.49; P < 0.0001). Serum bone Gla protein and 25-hydroxyvitamin D concentrations were lower in patients than controls (P < 0.0001), whereas ionized Ca concentrations were higher in patients (1.277 +/- 0.041 mmol/L) than controls (1.210 +/- 0.049; P < 0.0001), correlating with the Barthel index. Multivariate linear regression identified vitamin K1, bone Gla protein, 25-hydroxyvitamin D, ionized calcium, and the Barthel index as independent bone mineral density determinants on the hemiplegic side and 25-hydroxyvitamin D, calcium, and the Barthel index on the intact side. Immobilization and vitamin K deficiency had stronger osteopenic effects on the hemiplegic side than contralaterally.

Menatetrenone ameliorates osteopenia in disuse-affected limbs of vitamin D- and K-deficient stroke patients

Significant reduction in bone mineral density (BMD) occurs in stroke patients on the hemiplegic and contralateral sides, correlating with the degree of paralysis and vitamin D and K deficiency due to malnutrition, and increasing the risk of hip fracture. We evaluated the efficacy of vitamin K2 (menatetrenone: menaquinone-4; MK-4) in maintaining BMD by comparing serum biochemical indices of bone metabolism between treated and untreated patients. In a random and prospective study, of 108 hemiplegic patients following stroke, 54 received 45 mg menatetrenone daily (MK-4 group, n = 54) for 12 months, and the remaining 54 (untreatment group) did not. Nine patients excluded from the study. The BMD in the second metacarpals and serum indices of bone metabolism were determined. BMD on the hemiplegic side increased by 4.3% in the MK-4 group and decreased by 4.7% in the untreated group (p < 0.0001), while BMD on the intact side decreased by 0.9% in the MK-4 group and by 2.7% in the untreated group (p < 0.0001). At baseline, patients of both groups showed vitamin D and K1 deficiencies, high serum levels of ionized calcium, pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), and low levels of parathyroid hormones (PTH) and bone Gla proteins (BGP), indicating that immobilization-induced hypercalcemia inhibits renal synthesis of 1, 25-dihydroxyvitamin D (1, 25-[OH]2D) and compensatory PTH secretion. Both vitamins K1 and K2 increased by 97.6% and 666.9%, respectively, in the MK-4 group. Correspondingly, a significant increase in BGP and decreases in both ICTP and calcium were observed in the MK-4 group, in association with a simultaneous increase in both PTH and 1, 25-[OH]2D. One patient in the untreated group suffered from a hip fracture, compared with none in the MK-4 group. The treatment with MK-4 can increase the BMD of disused and vitamin D- and K-deficient hemiplegic bone by increasing the vitamin K concentration, and it also can decrease calcium levels through inhibition of bone resorption, resulting in an increase in 1, 25-[OH]2D concentration.