The association between myasthenia gravis and risk of fracture: a systematic review and meta-analysis.

Patients with myasthenia gravis (MG), because of their muscle weakness and exposure to corticosteroids treatment, are generally considered to be at increased risk for osteoporosis or fracture. However, clinical evidence of this issue is lacking. In this review, we systematically searched databases, including Cochrane Library, PubMed, Embase, and Airiti library from inception to the end of November 2023 for cohort studies that compared participants with MG and participants without MG for incidence of osteoporosis or fracture. We used the Newcastle-Ottawa Scale for quality assessment. In total, we included 3 studies with 34,865 participants. The pooled meta-analysis using the random effect model demonstrated no significant difference in risk of fracture in the MG group (odds ratio = 1.52; 95% confidence interval = 0.74 to 3.12; I2 = 93%; between-study variance [τ2] = 0.32) compared with that for the non-MG group. Due to limited studies, we could not perform a quantitative analysis for risk of osteoporosis. In conclusion, we found no robust evidence to support the proposition that patients with MG are at higher risk for fracture than general comparators. The explanations and underlying mechanisms of this finding remain unclear, we therefore conclude that additional studies are warranted.

Epidemiology, Patient Characteristics, and Treatment Patterns of Myasthenia Gravis in Taiwan: A Population-Based Study.

INTRODUCTION: Myasthenia gravis (MG) is a chronic neuromuscular disease leading to significant disease burden. This study aimed to investigate the epidemiology of MG in Taiwan. METHODS: A retrospective study was conducted using the Taiwan National Health Insurance Research Database. Prevalent patients with MG diagnosis (either ocular or generalized MG) from 2013 to 2019 were identified, and 2813 patients with initial MG diagnosis from 2014 to 2019 were further defined as the incident cohort. Patient characteristics, treatment patterns, and the occurrence of MG-related events were analyzed. RESULTS: The number of prevalent patients with MG increased from 4476 in 2013 to 5752 in 2019, with the prevalence rate increasing from 19 to 24 per 100,000 population. The incidence rate also slightly increased from 1.9 to 2.3 per 100,000 population during the study period. Almost all incident patients (99%, n = 2791) received MG-related treatment during the follow-up period. Among 1876 patients who received monotherapy as their initial treatment in the outpatient setting, the mean time from the index date to initial treatment was 48.8 (standard deviation 164.3) days, and most patients received acetylcholinesterase inhibitors (88.5%, n = 1661) as their initial treatment. During the first year after the index date, 133 (4.7%) incident patients experienced their first myasthenic crisis, and 96.2% of these events occurred within 3 months. CONCLUSION: The prevalence of MG increased steadily in Taiwan, and the treatment of patients with MG was consistent with guidelines. Despite a high treatment rate, patients still experienced MG-related events, highlighting the limitation of current treatments and emphasizing the need for early intervention and novel treatment approaches.

Assessing the length of hospital stay for patients with myasthenia gravis based on the data mining MARS approach.

Predicting the length of hospital stay for myasthenia gravis (MG) patients is challenging due to the complex pathogenesis, high clinical variability, and non-linear relationships between variables. Considering the management of MG during hospitalization, it is important to conduct a risk assessment to predict the length of hospital stay. The present study aimed to successfully predict the length of hospital stay for MG based on an expandable data mining technique, multivariate adaptive regression splines (MARS). Data from 196 MG patients' hospitalization were analyzed, and the MARS model was compared with classical multiple linear regression (MLR) and three other machine learning (ML) algorithms. The average hospital stay duration was 12.3 days. The MARS model, leveraging its ability to capture non-linearity, identified four significant factors: disease duration, age at admission, MGFA clinical classification, and daily prednisolone dose. Cut-off points and correlation curves were determined for these risk factors. The MARS model outperformed the MLR and the other ML methods (including least absolute shrinkage and selection operator MLR, classification and regression tree, and random forest) in assessing hospital stay length. This is the first study to utilize data mining methods to explore factors influencing hospital stay in patients with MG. The results highlight the effectiveness of the MARS model in identifying the cut-off points and correlation for risk factors associated with MG hospitalization. Furthermore, a MARS-based formula was developed as a practical tool to assist in the measurement of hospital stay, which can be feasibly supported as an extension of clinical risk assessment.

Tumor size combined with staging systems for thymoma recurrence prediction: A 28-year experience.

Background: We evaluated a new thymoma prognosis prediction model by combining current staging systems with tumor size. Methods: The clinical records of thymoma patients in a single center between January 1993 and December 2021 were collected, and data on tumor size and stage and recurrence-free survival (RFS) was obtained. The prediction model was designed by combining staging with tumor size. Results: During 28 years, 219 thymoma patients were enrolled. Twenty-seven patients had a median RFS of 8.2 years. Further, 153 patients were categorized into limited stage and 66 patients into advanced stage. The RFS was statistically different between these two groups (P = 0.022). The largest area under the curve (AUC) of receiver operating characteristic (ROC) was the dividing group as 5 cm (AUC: 0.804). Conclusions: Combining tumor staging and size improves thymoma recurrence prediction. Patients with advanced stage and tumor size >5 cm may show a poor prognosis.

Decreased Brain Structural Network Connectivity in Patients with Mild Cognitive Impairment: A Novel Fractal Dimension Analysis.

Mild cognitive impairment (MCI) is widely regarded to be the intermediate stage to Alzheimer's disease. Cerebral morphological alteration in cortical subregions can provide an accurate predictor for early recognition of MCI. Thirty patients with MCI and thirty healthy control subjects participated in this study. The Desikan-Killiany cortical atlas was applied to segment participants' cerebral cortex into 68 subregions. A complexity measure termed fractal dimension (FD) was applied to assess morphological changes in cortical subregions of participants. The MCI group revealed significantly decreased FD values in the bilateral temporal lobes, right parietal lobe including the medial temporal, fusiform, para hippocampal, and also the orbitofrontal lobes. We further proposed a novel FD-based brain structural network to compare network parameters, including intra- and inter-lobular connectivity between groups. The control group had five modules, and the MCI group had six modules in their brain networks. The MCI group demonstrated shrinkage of modular sizes with fewer components integrated, and significantly decreased global modularity in the brain network. The MCI group had lower intra- and inter-lobular connectivity in all lobes. Between cerebral lobes, the MCI patients may maintain nodal connections between both hemispheres to reduce connectivity loss in the lateral hemispheres. The method and results presented in this study could be a suitable tool for early detection of MCI.

Development of an Objective Structured Clinical Examination Station for Pediatric Occupational Therapy and an Evaluation of Its Quality.

IMPORTANCE: The Objective Structured Clinical Examination (OSCE) is a highly valued measure of students' clinical competencies in medical education. However, few studies have reported on the administration of the OSCE in pediatric occupational therapy education. OBJECTIVE: To describe the development of a pediatric occupational therapy OSCE station to evaluate students' use of a standardized assessment and examine its standard setting, failure rates, and psychometric properties. DESIGN: Prospective, cross-sectional, observational study design. SETTING: Three OSCE stations in a university clinical skills center. PARTICIPANTS: Five experienced occupational therapists, 60 examinees, 44 child standardized patients, 44 chaperones, and 15 examiners. MEASURES: The sum of the rating scale and the global performance scores were used. The rating scale measured the examinee's clinical competences in administering a standardized assessment. The 5-point global performance score was used to evaluate the examinee's whole performance. RESULTS: The OCSE station's expert validity was acceptable (item-level content validity index [CVI] = 0.8-1.0; scale-level CVI = 0.98). Passing scores according to the Angoff method (passing score = 14) and the contrasting-groups M-SD method (passing score = 13) were similar. Failure rates were high (61.7%-73.3%). Internal consistency was acceptable (Cronbach's α = .78). No significant examiner effect was found (p = .554), and interexaminer reliability was acceptable (item score = 0.58-1.00; sum of the rating scale score = 0.97; global performance score = 0.79). CONCLUSIONS AND RELEVANCE: The OSCE station for using a standardized assessment is a reliable and valid measure of students' interpersonal communication skills and assessment skills. What This Article Adds: The OSCE for education in pediatric occupational therapy is both effective and rigorous.

Utilization of Decision Tree Algorithms for Supporting the Prediction of Intensive Care Unit Admission of Myasthenia Gravis: A Machine Learning-Based Approach.

Myasthenia gravis (MG), an acquired autoimmune-related neuromuscular disorder that causes muscle weakness, presents with varying severity, including myasthenic crisis (MC). Although MC can cause significant morbidity and mortality, specialized neuro-intensive care can produce a good long-term prognosis. Considering the outcomes of MG during hospitalization, it is critical to conduct risk assessments to predict the need for intensive care. Evidence and valid tools for the screening of critical patients with MG are lacking. We used three machine learning-based decision tree algorithms, including a classification and regression tree, C4.5, and C5.0, for predicting intensive care unit (ICU) admission of patients with MG. We included 228 MG patients admitted between 2015 and 2018. Among them, 88.2% were anti-acetylcholine receptors antibody positive and 4.7% were anti-muscle-specific kinase antibody positive. Twenty clinical variables were used as predictive variables. The C5.0 decision tree outperformed the other two decision tree and logistic regression models. The decision rules constructed by the best C5.0 model showed that the Myasthenia Gravis Foundation of America clinical classification at admission, thymoma history, azathioprine treatment history, disease duration, sex, and onset age were significant risk factors for the development of decision rules for ICU admission prediction. The developed machine learning-based decision tree can be a supportive tool for alerting clinicians regarding patients with MG who require intensive care, thereby improving the quality of care.

Assessment of Sarcopenia and Obesity in Patients with Myasthenia Gravis Using Dual-Energy X-ray Absorptiometry: A Cross-Sectional Study.

Sarcopenia and obesity can negatively impact quality of life and cause chronic fragility, and are associated with neuromuscular diseases, including myasthenia gravis (MG). The long-term consequences of body composition changes in chronic MG remain unknown; we therefore evaluated changes in body composition, including sarcopenia, obesity, lean body mass, and the prevalence of sarcopenic obesity in patients. In this cross-sectional study, 35 patients with MG (mean age: 56.1 years) and 175 matched controls were enrolled. Body fat mass and skeletal muscle mass were measured using whole body dual-energy X-ray absorptiometry. Patients with MG exhibited a higher prevalence of obesity and higher android adiposity and total body fat percentage than those of controls. Although the prevalence of sarcopenia and sarcopenic obesity did not increase with age, there was a decrease in arm and android muscle mass in patients with MG compared with controls. Lower muscle mass percentages were correlated with increased age and MG severity, but not with corticosteroid use. Thus, MG is associated with increased risk for obesity and decreased muscle mass with aging, regardless of corticosteroid use. Therefore, accurate diagnosis of body composition changes in MG could facilitate the application of appropriate therapies to promote health, improve quality of life, and prevent fragility.

Clinical Predictors of Prolonged Hospital Stay in Patients with Myasthenia Gravis: A Study Using Machine Learning Algorithms.

Myasthenia gravis (MG) is an autoimmune disorder that causes muscle weakness. Although the management is well established, some patients are refractory and require prolonged hospitalization. Our study is aimed to identify the important factors that predict the duration of hospitalization in patients with MG by using machine learning methods. A total of 21 factors were chosen for machine learning analyses. We retrospectively reviewed the data of patients with MG who were admitted to hospital. Five machine learning methods, including stochastic gradient boosting (SGB), least absolute shrinkage and selection operator (Lasso), ridge regression (Ridge), eXtreme gradient boosting (XGboost), and gradient boosting with categorical features support (Catboost), were used to construct models for identify the important factors affecting the duration of hospital stay. A total of 232 data points of 204 hospitalized MG patients admitted were enrolled into the study. The MGFA classification, treatment of high-dose intravenous corticosteroid, age at admission, treatment with intravenous immunoglobulins, and thymoma were the top five significant variables affecting prolonged hospitalization. Our findings from machine learning will provide physicians with information to evaluate the potential risk of MG patients having prolonged hospital stay. The use of high-dose corticosteroids is associated with prolonged hospital stay and to be used cautiously in MG patients.

Changes in Physical Fitness and Body Composition Associated with Physical Exercise in Patients with Myasthenia Gravis: A Longitudinal Prospective Study.

There is a lack of guidelines for physical exercise in patients with myasthenia gravis (MG). A few pilot studies have shown that exercise can be safely applied to patients with MG. However, how physical exercise affects body composition, disease function, and disease severity remains unknown. In this prospective study, we enrolled 34 patients with MG with stable condition and evaluated the disease severity, physical fitness parameters, and body composition (measured using whole-body dual-energy X-ray absorptiometry (DXA)), before and after conducting a 24-week physical exercise regimen of aerobic and resistance strength training. The outcomes were measured by DXA, quantitative MG (QMG) score, quality of life score, handgrip strength and walking speed. During the training regimen, participants were free to decide how many exercise sessions per week and regularly reported their weekly exercise time. The physical exercise program was well tolerated by the participants, the parameters of the QMG score and handgrip strength improved, and participants' body composition did not change significantly. The high exercise group experienced greater deterioration in muscle mass in the arms, but exhibited a greater improvement in forced vital capacity, walking speed, and symptom severity. The group with low QMG scores improved more in terms of physical fitness, including walking speed. These findings indicate that physical exercise is well tolerated by patients with MG, and is accompanied by improved muscular and physical functions. We propose that physical exercise is safe, effective, and appropriate for patients with well-regulated MG.

Pioglitazone Ameliorates Lipopolysaccharide-Induced Behavioral Impairment, Brain Inflammation, White Matter Injury and Mitochondrial Dysfunction in Neonatal Rats.

Previous studies have demonstrated that pioglitazone, a peroxisome proliferator-activated receptor gamma (PPARγ) agonist, inhibits ischemia-induced brain injury. The present study was conducted to examine whether pioglitazone can reduce impairment of behavioral deficits mediated by inflammatory-induced brain white matter injury in neonatal rats. Intraperitoneal (i.p.) injection of lipopolysaccharide (LPS, 2 mg/kg) was administered to Sprague-Dawley rat pups on postnatal day 5 (P5), and i.p. administration of pioglitazone (20 mg/kg) or vehicle was performed 5 min after LPS injection. Sensorimotor behavioral tests were performed 24 h after LPS exposure, and changes in biochemistry of the brain was examined after these tests. The results show that systemic LPS exposure resulted in impaired sensorimotor behavioral performance, reduction of oligodendrocytes and mitochondrial activity, and increases in lipid peroxidation and brain inflammation, as indicated by the increment of interleukin-1ß (IL-1ß) levels and number of activated microglia in the neonatal rat brain. Pioglitazone treatment significantly improved LPS-induced neurobehavioral and physiological disturbances including the loss of body weight, hypothermia, righting reflex, wire-hanging maneuver, negative geotaxis, and hind-limb suspension in neonatal rats. The neuroprotective effect of pioglitazone against the loss of oligodendrocytes and mitochondrial activity was associated with attenuation of LPS-induced increment of thiobarbituric acid reactive substances (TBARS) content, IL-1ß levels and number of activated microglia in neonatal rats. Our results show that pioglitazone prevents neurobehavioral disturbances induced by systemic LPS exposure in neonatal rats, and its neuroprotective effects are associated with its impact on microglial activation, IL-1ß induction, lipid peroxidation, oligodendrocyte production and mitochondrial activity.

Using Fractal Dimension Analysis with the Desikan-Killiany Atlas to Assess the Effects of Normal Aging on Subregional Cortex Alterations in Adulthood.

Normal aging is associated with functional and structural alterations in the human brain. The effects of normal aging and gender on morphological changes in specific regions of the brain are unknown. The fractal dimension (FD) can be a quantitative measure of cerebral folding. In this study, we used 3D-FD analysis with the Desikan-Killiany (DK) atlas to assess subregional morphological changes in adulthood. A total of 258 participants (112 women and 146 men) aged 30-85 years participated in this study. Participants in the middle-age group exhibited a decreased FD in the lateral frontal lobes, which then spread to the temporal and parietal lobes. Men exhibited an earlier and more significant decrease in FD values, mainly in the right frontal and left parietal lobes. Men exhibited more of a decrease in FD values in the subregions on the left than those in the right, whereas women exhibited more of a decrease in the lateral subregions. Older men were at a higher risk of developing mild cognitive impairment (MCI) and exhibited age-related memory decline earlier than women. Our FD analysis using the DK atlas-based prediagnosis may provide a suitable tool for assessing normal aging and neurodegeneration between groups or in individual patients.

Alteration of the Intra- and Inter-Lobe Connectivity of the Brain Structural Network in Normal Aging.

The morphological changes in cortical parcellated regions during aging and whether these atrophies may cause brain structural network intra- and inter-lobe connectivity alterations are subjects that have been minimally explored. In this study, a novel fractal dimension-based structural network was proposed to measure atrophy of 68 parcellated cortical regions. Alterations of structural network parameters, including intra- and inter-lobe connectivity, were detected in a middle-aged group (30-45 years old) and an elderly group (50-65 years old). The elderly group exhibited significant lateralized atrophy in the left hemisphere, and most of these fractal dimension atrophied regions were included in the regions of the "last-in, first-out" model. Globally, the elderly group had lower modularity values, smaller component size modules, and fewer bilateral association fibers. They had lower intra-lobe connectivity in the frontal and parietal lobes, but higher intra-lobe connectivity in the temporal and occipital lobes. Both groups exhibited similar inter-lobe connecting pattern. The elderly group revealed separations, sparser long association fibers, commissural fibers, and lateral inter-lobe connectivity lost effect, mainly in the right hemisphere. New wiring and reconfiguring modules may have occurred within the brain structural network to compensate for connectivity, decreasing and preventing functional loss in cerebral intra- and inter-lobe connectivity.

Using children as standardized patients in OSCE in pediatric occupational therapy.

BACKGROUND: Objective structured clinical examinations (OSCEs) have been administered in physical and psychiatric occupational therapy (OT) education, but not in pediatric OT education. The objectives were to examine the satisfaction and the influences of OSCE in pediatric OT on all participants. METHODS: The OSCE contained evaluation, intervention, and parent education stations. Sixty examinees, 44 child standardized patients (SPs), 44 chaperones, three playroom managers, 14 OSCE assistants, and 15 examiners participated in the OSCE. An OSCE video and three playrooms were prepared for child SPs. RESULTS: Ninety percent of the child SPs liked taking part in the OSCE and 75-85% expressed interest in participating in an OSCE the following year. Their parents appreciated the chaperones accompanying their children and giving them a memorable day. 88.3% of the examinees thought that the OSCE was helpful for their upcoming clinical training. 73.3% preferred the OSCE over the written exam. 60-93.4% considered the implementation appropriate. Most of the examiners thought that the content (80-100%) and the implementation (93.3-100%) were appropriate. Many chaperones reported having valuable experiences. CONCLUSIONS: It is practical using child SPs in OSCE in pediatric OT. The OSCE was beneficial to all participants. It is recommended that OSCEs be included in pediatric OT education.

Can osteoporosis increase the incidence of heart failure in adults?

BACKGROUND: Recent studies have suggested shared comorbidities between heart failure and osteoporosis. In addition, patients with osteoporosis are associated with increased risks of developing cardiovascular disease. METHODS: A retrospective cohort analysis was conducted to determine the association between osteoporosis and heart failure. Data was from the Longitudinal Health Insurance Database 2000 (LHID 2000), Taiwan. Patients with newly diagnosed osteoporosis were identified, and osteoporosis-free controls were randomly selected from the general population and frequency matched according to age, sex, and index year using the LHID 2000. We analyzed the risks of heart failure using Cox proportional-hazards regression models. RESULTS: During the mean follow-up of 7.1 ± 3.5 years, the cumulative incidence of heart failure was 2.24% higher in the osteoporosis cohort than in the comparison cohort (p < .001). The overall incidence of heart failure was 10.3 versus 7.62 per 1000 person-years in osteoporosis patients and controls, respectively, with an adjusted HR of 1.13 (95% CI = 1.06-1.21). CONCLUSION: We observed a higher incidence of developing heart failure in Taiwanese adults with osteoporosis, especially in those with chronic comorbidities. There might be linking pathophysiology and mechanisms from osteoporosis to heart failure.

Beneficial effects of prolonged blood pressure control after carotid artery stenting.

OBJECTIVES: The main purpose of this study was to investigate whether carotid artery stenting (CAS) plus medicine in patients with severe carotid artery stenosis provide a better long-term blood pressure (BP) control compared to other medical treatments alone. The other aim was to explore the correlation between post-CAS hypotension within 6 h and long-term BP reductions after CAS. MATERIALS AND METHODS: Patients with severe carotid stenosis were recruited either in the CAS group or in the medication group. BPs and the number of classes of antihypertensive agents were recorded at baseline, 6, and 12 months. Extra BP information was collected at 6 h, 3 days, and 1 month after CAS. Univariate and multivariate linear regressions were performed to test the relationship of BP changes among CAS and medication groups after 6 and 12 months of follow-up. Univariate linear regressions were also used to determine the correlations between the mean or maximal systolic BP (SBP) reductions at 6 h and 1 year post-CAS. RESULTS: In total, 72 members in the CAS group and 82 members in the medication group were recruited. Compared with the medication group, patients in the CAS group had greater BP reductions at 6 and 12 months of follow-up after adjusting for confounding factors (13.56 mmHg at 6 months, P=0.0002; 16.98 mmHg at 12 months, P<0.0001). This study also shows significant positive correlations between the mean or maximal SBP reductions 6 h post-CAS and SBP reductions 1 year post-CAS (ß =0.20±0.07, P=0.0067 and ß =0.47±0.10, P<0.0001, respectively). CONCLUSION: As compared to medical treatment alone, CAS may provide significant beneficial effect on long-term BP control 1 year post-CAS. Furthermore, SBP reductions 6 h post-CAS may predict the SBP reductions 1 year post-CAS.

Can teaching hospitals use serial formative OSCEs to improve student performance?

BACKGROUND: We report on interns' clinical competence and experiences of an objective structured clinical examination (OSCE) training program over 3 years. We aimed to determine whether repeated formative OSCEs allow teaching hospitals to improve the effectiveness of clinical training and help interns to achieve high scores in the national summative OSCE. METHODS: This study included 207 participants, among whom 82 were interns who had completed four mock OSCEs and a national OSCE at the clinical center of Cathay General Hospital (CGH). The other 125 participants were final-year medical students from Fu-Jen University who had completed the national OSCE between 2013 and 2015 at one of four teaching hospitals (including CGH). CGH interns were categorized into three groups according to the medical school attended and Fu-Jen University students were grouped according to their training hospitals. CGH held four mock OSCEs (30 stations), whereas each of the four training hospitals for Fu-Jen students each held one or two OSCEs (6-12 stations) annually. Differences in the mean OSCE scores among groups were analyzed. The medical school attended, pre-internship OSCE experience and the frequency of mock OSCEs held by training hospitals were independent factors in this study. RESULTS: The cumulative mean scores for five OSCEs among three groups of students trained at CGH tended to increase from the first OSCE (OSCE1) to the fifth (OSCE5). The mean score of the students who attended Fu-Jen Medical School was higher than that of students who graduated from foreign medical schools in all five OSCEs; however, the differences were significant only for OSCE2 (P = 0.022) and OSCE3 (P = 0.027). The mean national OSCE scores of FJU students showed no statistically significant differences among the four training hospitals for 2013; however, students training at CGH had significantly higher mean scores in the 2014 (P = 0.001) and 2015 (P = 0.005) OSCEs compared with students training at the other three hospitals. CONCLUSIONS: Serial administration of formative OSCEs by teaching hospitals enhances the performance of students on the sequential summative OSCE. Such programs provide multiple opportunities for students to practice their clinical skills, and for faculty to develop their teaching, assessment and consensus building skills.

Higher risk of myasthenia gravis in patients with thyroid and allergic diseases: a national population-based study.

The aim of this study was to determine the risk of myasthenia gravis (MG) in patients with allergic or autoimmune thyroid disease in a large cohort representing 99% of the population in Taiwan. Data from the Taiwan National Health Insurance Database were used to conduct retrospective analyses. The study comprised 1689 adult patients with MG who were 4-fold frequency matched to those without MG by sex, age, and assigned the same index year. Multivariate logistic regression models were used to calculate the odds ratios and 95% confidence intervals for the association between allergic or autoimmune thyroid disease and MG. An increased subsequent risk of MG was observed in the patients with allergic conjunctivitis (AC), allergic rhinitis, Hashimoto thyroiditis, and Graves disease. The adjusted odds ratios (aORs) were 1.93 (1.71-2.18), 1.26 (1.09-1.45), 2.87 (1.18-6.97), and 3.97 (2.71-5.83), respectively. The aORs increased from 1.63 (1.43-1.85) in a patient with only 1 allergic or autoimmune thyroid disease to 2.09 (1.75-2.49) in a patient with 2 thyroid or allergic diseases to 2.82 (2.19-3.64) in a patient with ≥3 thyroid or allergic diseases. MG was associated with the cumulative effect of concurrent allergic and autoimmune thyroid disease with combined AC and Hashimoto thyroiditis representing the highest risk (aOR = 15.62 [2.88-87.71]). This population-based case-control study demonstrates the association between allergic or autoimmune thyroid disease and the risk of MG. The highest risk of subsequent MG was associated with combined AC and Hashimoto thyroiditis.