Fracture rate in patients with myasthenia gravis: the general practice research database

Ten-year fracture risk in Japanese patients with myasthenia gravis: A comprehensive assessment using the fracture risk assessment tool

BACKGROUND

Myasthenia gravis (MG) is an immune disorder that causes muscle weakness with an increasing prevalence, particularly among the elderly in Japan. Glucocorticoid treatment for MG is problematic for bone health because of reduced bone density and increased fracture risk. The fracture risk assessment tool (FRAX®) can estimate fracture risk, but its applicability in patients with MG remains uncertain.

METHODS

A prospective cohort study was conducted on 54 patients with MG between April and July 2012. Bone mineral density (BMD) was measured, and FRAX® scores were calculated with and without BMD. We also adjusted FRAX® scores based on glucocorticoid dosage. Patients were monitored for major osteoporotic fractures (MOF) until June 2022. Statistical analyses included Kaplan-Meier curves and Cox proportional hazards models.

RESULTS

The study group included 12 men and 42 women with a mean age of 62 years. Higher FRAX® scores correlated with increased fracture risk, particularly in the hip and lumbar regions. The 10-year fracture-free rate was significantly lower in the high-FRAX® score group. The FRAX® score using BMD is a significant predictor of MOF risk. The hazard ratio for FRAX® scores was 1.17 (95% CI 1.10-1.26).

CONCLUSION

We demonstrated the effectiveness of the FRAX® tool in assessing fracture risk among patients with MG. High FRAX® scores correlated with increased fracture risk, emphasizing its importance. These findings support the incorporation of FRAX® assessment into clinical management to enhance patient care and outcomes. However, the small sample size and observational nature suggest a need for further research.

Prevalence of co-morbidity and history of recent infection in patients with neuromuscular disease: A cross-sectional analysis of United Kingdom primary care data

BACKGROUND

People with neuromuscular disease (NMD) experience a broader range of chronic diseases and health symptoms compared to the general population. However, no comprehensive analysis has directly quantified this to our knowledge.

METHODS

We used a large UK primary care database (Clinical Practice Research Datalink) to compare the prevalence of chronic diseases and other health conditions, including recent infections between 23,876 patients with NMD ever recorded by 2019 compared to 95,295 age-sex-practice matched patients without NMD. Modified Poisson regression estimated Prevalence Ratios (PR) to summarise the presence of the disease/condition ever (or for infections in 2018) in NMD patients versus non-NMD patients.

RESULTS

Patients with NMD had significantly higher rates for 16 of the 18 conditions routinely recorded in the primary care Quality and Outcomes Framework (QOF). Approximately 1-in-10 adults with NMD had ≥4 conditions recorded (PR = 1.39, 95%CI 1.33-1.45). Disparities were more pronounced at younger ages (18-49). For other (non-QOF) health conditions, significantly higher recorded levels were observed for rarer events (pulmonary embolism PR = 1.96 95%CI 1.76-2.18, hip fractures PR = 1.65 95%CI 1.47-1.85) as well as for more common primary care conditions (constipation PR = 1.52 95%CI 1.46-1.57, incontinence PR = 1.52 95%CI 1.44-1.60). The greatest co-morbidity burden was in patients with a myotonic disorder. Approximately 1-in-6 (17.1%) NMD patients had an infection recorded in the preceding year, with the risk of being hospitalised with an infection nearly double (PR = 1.92, 95%CI 1.79-2.07) compared to non-NMD patients.

CONCLUSION

The burden of chronic co-morbidity among patients with NMD is extremely high compared to the general population, and they are also more likely to present in primary and secondary care for acute events such as infections.

The use of oral glucocorticoids and the risk of major osteoporotic fracture in patients with myasthenia gravis

Oral glucocorticoids may increase major osteoporotic fracture risk (MOF) in myasthenia gravis patients. To assess this risk, we performed a case-control study including all Danish patients with a MOF between 1995 and 2011. We also pooled our data with data from another study. We found no increased risk. Osteoporosis prevention remains advisable.

PURPOSE/INTRODUCTION

The prolonged use of high doses of oral glucocorticoids (GCs), a common treatment in patients with myasthenia gravis (MG), may increase major osteoporotic fracture (MOF) risk. Previous epidemiological studies did not exclusively focus on patients with MG or had relatively few GC-exposed MG patients. Aims were to evaluate the risk of MOF in MG patients using oral GCs in a large study population and to perform a pooled analysis with data from previous work.

METHODS

A population-based case-control study (1995-2011) was conducted using the Danish National Health Service. Cases had sustained a MOF, and controls had not. All were aged ≥ 18 years. Multivariate conditional logistic regression estimated odds ratios (ORs) among MG patients using oral GCs versus non-users. Adjustments were made for comorbidities and comedications. In the pooled analysis, results were pooled by the use of generic inverse variance methods, assuming a random-effects model.

RESULTS

We identified 376,858 cases and 376,858 controls. MOF risk was not elevated in MG patients currently using oral GCs compared to MG patients not on oral GCs (OR_adj.: 1.26 (95% CI 0.68-2.33)). The use of the highest cumulative dose of oral GCs (≥ 7 g) did not show an increased risk of MOF among MG patients (OR_adj.: 2.00 (95% CI 0.90-4.44)). Our pooled analysis also showed no association between oral GC use and MOF risk.

CONCLUSION

This study showed that oral GC use in patients with MG was not associated with increased risk of MOF in our case-control study and pooled analysis. Osteoporosis prevention in MG patients based on clinical guidelines remains advisable.

Fracture Risk in Patients with Myasthenia Gravis: A Population-Based Cohort Study

BACKGROUND

Prednisone is a common treatment for myasthenia gravis (MG), and osteoporosis is a known potential risk of chronic prednisone therapy.

OBJECTIVE

Our aim was to evaluate the risk of serious fractures in a population-based cohort of MG patients.

METHODS

An inception cohort of patients with MG was identified from administrative health data in Ontario, Canada between April 1, 2002 and December 31, 2015. For each MG patient, we matched 4 general population comparators based on age, sex, and region of residence. Fractures were identified through emergency department and hospitalization data. Crude overall rates and sex-specific rates of fractures were calculated for the MG and comparator groups, as well as rates of specific fractures. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression.

RESULTS

Among 3,823 incident MG patients (followed for a mean of 5 years), 188 (4.9%) experienced a fracture compared with 741 (4.8%) fractures amongst 15,292 matched comparators. Crude fracture rates were not different between the MG cohort and matched comparators (8.71 vs. 7.98 per 1000 patient years), overall and in men and women separately. After controlling for multiple covariates, MG patients had a significantly lower risk of fracture than comparators (HR 0.74, 95% CI 0.63-0.88).

CONCLUSIONS

In this large, population-based cohort of incident MG patients, MG patients were at lower risk of a major fracture than comparators. The reasons for this finding are unclear but may highlight the importance osteoporosis prevention.

Effects of Neurological Disorders on Bone Health

Neurological diseases, particularly in the context of aging, have serious impacts on quality of life and can negatively affect bone health. The brain-bone axis is critically important for skeletal metabolism, sensory innervation, and endocrine cross-talk between these organs. This review discusses current evidence for the cellular and molecular mechanisms by which various neurological disease categories, including autoimmune, developmental, dementia-related, movement, neuromuscular, stroke, trauma, and psychological, impart changes in bone homeostasis and mass, as well as fracture risk. Likewise, how bone may affect neurological function is discussed. Gaining a better understanding of brain-bone interactions, particularly in patients with underlying neurological disorders, may lead to development of novel therapies and discovery of shared risk factors, as well as highlight the need for broad, whole-health clinical approaches toward treatment.

Effects of alendronate and alfacalcidol on bone in patients with myasthenia gravis initiating glucocorticoids treatment

OBJECTIVE

Glucocorticoids (GCs) are the first-line treatment for myasthenia gravis (MG) and act as long-term immunosuppressants. However, GCs can induce osteoporosis and bone fractures. In this study, we evaluate the effects of oral alendronate and alfacalcidol, or alfacalcidol alone on the bone of Chinese patients with MG who will initiate treatment with GCs.

DESIGN AND METHODS

A total of 75 patients were included in this 12-month prospective, open-label, single-centre study. Patients with bone mineral density (BMD) T-score less than -1.0 at baseline were treated with 70 mg of alendronate per week. Patients with BMD T-score greater than -1.0 at baseline were included in the alfacalcidol-alone group. Patients in two groups were treated with 0.25 μg of alfacalcidol every other day and 600 mg of calcium daily.

RESULTS

After 12 months of treatment, the mean BMD of lumbar spine, femoral neck and total hip increased by 3.4% (P = .002), 1.8% (P = .21) and 2.6% (P = .02), respectively, in alendronate group. In alfacalcidol-alone group, the mean BMD of lumbar spine, femoral neck and total hip decreased by 6.1%, 3.2% and 3.3%, respectively (all P < .001 vs baseline).

CONCLUSIONS

We demonstrated for the first time that treatment with alendronate combined with alfacalcidol significantly increased BMD, decreased bone turnover biomarker levels and reduced the occurrence of hypercalciuria in a large cohort of Chinese patients with MG who initiated treatment with glucocorticoids. However, treatment with alfacalcidol alone failed to prevent bone loss in patients with MG receiving glucocorticoid therapy.

Negative impact of high cumulative glucocorticoid dose on bone metabolism of patients with myasthenia gravis

This current study aimed to evaluate the frequency of low bone mass, osteopenia, and osteoporosis in patients with myasthenia gravis (MG) and to investigate the possible association between bone mineral density (BMD) and plasma levels of bone metabolism markers. Eighty patients with MG and 62 controls BMD were measured in the right femoral neck and lumbar spine by dual-energy X-ray absorptiometry. Plasma concentrations of osteocalcin, osteopontin, osteoprotegerin, tumor necrosis factor (TNF-α), interleukin (IL)-1β, IL-6, dickkopf (DKK-1), sclerostin, insulin, leptin, adrenocorticotropic hormone, parathyroid hormone, and fibroblast growth factor (FGF-23) were analyzed by Luminex®. The mean age of patients was 41.9 years, with 13.5 years of length of illness, and a mean cumulative dose of glucocorticoids 38,123 mg. Patients had significant reduction in BMD of the lumbar, the femoral neck, and in the whole body when compared with controls. Fourteen percent MG patients had osteoporosis at the lumbar spine and 2.5% at the femoral neck. In comparison with controls, patients with MG presented lower levels of osteocalcin, adrenocorticotropic hormone, parathyroid hormone, sclerostin, TNF-α, and DKK-1 and higher levels of FGF-23, leptin, and IL-6. There was a significant negative correlation between cumulative glucocorticoid dose and serum calcium, lumbar spine T-score, femoral neck BMD, T-score, and Z-score. After multivariate analysis, higher TNF-α levels increased the likelihood of presenting low bone mass by 2.62. MG patients under corticotherapy presented low BMD and altered levels of bone markers.

Association between Glucocorticoid-Induced Osteoporosis and Myasthenia Gravis: A Cross-Sectional Study

Purpose

To investigate the association between glucocorticoid-induced osteoporosis and myasthenia gravis (MG) using a cross-sectional survey in Japan.

Methods

We studied 363 patients with MG (female 68%; mean age, 57 ± 16 years) who were followed at six Japanese centers between April and July 2012. We evaluated the clinical information of MG and fractures, bone markers, and radiological assessment. Quality of life was measured using an MG-specific battery, MG-QOL15.

Results

Glucocorticoids were administered in 283 (78%) of 363 MG patients. Eighteen (6%) of 283 MG patients treated with prednisolone had a history of osteoporotic fractures. The duration of glucocorticoid therapy, but not the dose of prednisolone, was associated with the osteoporotic fractures in MG patients. Bone mineral density was significantly decreased in the MG patients with fractures. The multivariate analyses showed that the total quantitative MG score was the only independent factor associated with osteoporotic fractures (OR = 1.30, 95% CI 1.02–1.67, p = 0.03). MG patients who had experienced fractures reported more severe difficulties in activities of daily living.

Conclusion

Glucocorticoid-induced osteoporosis aggravates quality of life in patients with MG.