Serum 25-hydroxyvitamin D levels and dermatomyositis: A 2-sample mendelian randomization study.

BACKGROUND: Previous studies have reported low serum 25-hydroxyvitamin D [25(OH)D] levels in dermatomyositis (DM) patients, but the exact causal relationship between them remains elusive. Our aim is to confirm the causal relationship between 25(OH)D and DM risk through a Mendelian randomization study. METHODS: Retrieve genome-wide association study (GWAS) data on 25(OH)D (n = 441 291) and DM (n cases = 201, n controls = 172 834) from the GWAS database (https://gwas.mrcieu.ac.uk/). Select single-nucleotide polymorphisms (SNPs) strongly correlated with 25(OH)D as instrumental variables (IVs). The primary analytical approach involves the use of the inverse-variance weighted method (IVW), supplemented by MR-Egger regression and weighted median methods to enhance the reliability of the results. Heterogeneity and sensitivity analyses were conducted using Cochran's Q and leave-one-out approaches, respectively. RESULTS: The IVW analysis confirmed a positive causal relationship between genetic variation in 25(OH)D levels and DM (OR = 2.36, 95% CI = 1.01-5.52, p = .048). Although not statistically significant (all p > .05), the other methods also suggested a protective effect of 25(OH)D on DM. Based on MR-Egger intercepts and Cochran's Q analysis, the selected SNPs showed no horizontal pleiotropy and heterogeneity. Sensitivity analysis demonstrated the robustness of the results against individual SNPs. CONCLUSION: We provide the first evidence of a causal relationship between 25(OH)D levels and DM. Our findings support the importance of measuring serum 25(OH)D levels and considering vitamin D supplementation in clinical practice for patients with DM.

Evaluation of the frequency and risk factors of spontaneous intramuscular hemorrhage associated with dermatomyositis.

Dermatomyositis (DM) is an idiopathic inflammatory myositis (IIM) characterized by skin manifestations and muscle involvement. Spontaneous intramuscular hemorrhage (SIH) is a fatal complication that is very rare in the course of DM, but not well known to rheumatologists. Our aim was to determine the frequency and possible risk factors of DM-related SIH. A retrospective analysis was conducted on a cohort of DM patients who were observed in the rheumatology department of the university hospital between 1998 and January 2024. The clinical, laboratory, radiological data of the patients and the treatments they received during the follow-up were analyzed. To determine possible risk factors for the development of SIH in the course of DM, our patients with DM were analyzed together with other rare SIH cases in the literature. The study included 42 of our DM patients. 32 of the patients (76.2%) were female. The median age of the patients was 53 (24-82) years, the median age of DM diagnosis of the patients was 47 (18-75) years, and the median duration of DM of the patients was 36 (2-276) months. 7.1% of patients had dysphagia, and 16.7% had intertitial lung disease (ILD). 5 (11.9%) patients were diagnosed with malignancy. The incidence rate of SIH development in our DM cohort was 0.238/100 patient years (95% CI 0.006-1.256). We tried to identify independent risk factors for SIH development by comparing our 41 DM patients without SIH with the data of patients with 23 DM-related SIH collected from the literature by adding our 1 patient (24 pts). Male sex (OR 4.97, 95% CI 1.66-14.92, p = 0.003), ILD presence (OR 9.71, 95% CI 2.99-31.47, p < 0.001), anti-MDA5 positivity (OR 16.0, 95% CI 1.60-159.3, p = 0.006), anti-Ro52 positivity (OR 11.6, 95% CI 2.93-46.34, p < 0.001), heparin use (OR 4.42, 95% CI 2.68-7.24, p < 0.001), intravenous immunoglobulin (IVIG) use (OR 11.7, 95% CI 2.26-60.54, p < 0.001), and steroid dose (OR 1.03, 95% CI 1.00-1.05, p = 0.005) were identified as risk factors for the development of SIH in the univariate analysis. The death rate due to hemorrhage was 50%. No single risk factor was found to be associated with death. As a result, SIH may occasionally arise in patients with DM. Rheumatologists should be aware that patients with dysphagia and/or ILD, who are on heparin, getting high doses of steroids, and test positive for anti-MDA5 and/or anti-Ro52 antibodies may develop SIH in the early stages of DM.

Dynamic change in red cell distribution width as a predictor for short-time mortality in dermatomyositis-associated rapid progressive interstitial lung disease.

AIM: We aimed to explore a new and readily available practical marker for rapidly progressive interstitial lung disease (RP-ILD) and poor short-term outcomes in patients with idiopathic inflammatory myopathies (IIM). METHODS: A total of 1822 consecutive patients with IIM between 2009 and 2021 were evaluated retrospectively. All proven cases of naïve ILD with complete medical records were included. Red cell distribution width (RDW) values at the initial stage, 3 months and last follow-up were collected. The clinical characteristics and outcomes of the patients were recorded. RESULTS: We identified 532 patients with IIM with an average follow-up of 4 years. ILD prevalence was higher in patients of elevated RDW (p<0.001). The patients with ILD and elevated RDW had lower levels of PaO2/FiO2, FVC% and DLco% and a higher prevalence of RP-ILD than those with normal RDW (p<0.001). Prognostic analysis revealed that RDW was an independent risk factor for prognosis in patients with IIM-ILD (HR=2.9, p=0.03). Patients with dermatomyositis (DM) with RP-ILD with a change in RDW within 3 months (∆RDW-3) greater than 0 were more likely to die within 3 months. Moreover, the prevalence of ∆RDW-3>0 was higher in patients with RP-ILD and positive for anti-melanoma differentiation-associated gene 5 antibody who died within 3 months (87.5%) compared with those alive at 3 months (24.6%) (p<0.001). CONCLUSION: These findings suggest that repeated RDW assays could assist physicians in identifying patients with DM-ILD who were at a high risk of RP-ILD and death.

Prevalence of hearing loss, tinnitus, vertigo and sudden deafness among patients with polymyositis and dermatomyositis.

Little is known about a possible association of autoimmune inner ear disease among patients diagnosed with polymyositis (PM)/dermatomyositis (DM). This study aimed to explore differences in the prevalence of inner ear symptoms among patients with and without PM/DM using a nationwide population-based dataset. Data for this study were retrieved from the Taiwan National Health Insurance Research Database. The study sample included 1622 patients diagnosed with PM/DM and 8109 propensity-score matched comparison patients without PM/DM. We performed multivariate logistic regressions to calculate odds ratios (ORs) and 95% confidence interval (CI) for tinnitus, hearing loss, sudden deafness, and vertigo among patients with PM/DM versus comparison patients. Chi-square tests showed statistically significant differences between patients with PM/DM and comparison patients in the prevalence of tinnitus (16.1% vs. 12.7%, p < 0.001), non-conductive hearing loss (9.2% vs. 6.8%, p < 0.001), and vertigo (14.4% vs. 11.1%, p < 0.001). The adjusted ORs for tinnitus, non-conductive hearing loss, and vertigo, respectively, were 1.332 (95% CI = 1.147-1.547), 1.399 (95% CI = 1.154-1.696), and 1.374 (95% CI = 1.173-1.611) for patients with PM/DM when compared to comparison patients. Our study finds that patients with PM/DM have higher prevalence rates of tinnitus, non-conductive hearing loss, and vertigo than comparison patients.

Cancer Risk and Mortality in Hospitalized Patients With Idiopathic Inflammatory Myopathies in Western Australia.

OBJECTIVE: To compare cancer incidence, type, and survival between patients with idiopathic inflammatory myopathies (IIMs) in Western Australia (WA) and the general population. METHODS: Administrative health data for hospitalized patients with incident IIM (n = 803, 56.5% female, median age 62.0 yrs), classified by a validated algorithm as polymyositis (PM; 36.2%), dermatomyositis (DM; 27.4%), inclusion body myositis (IBM; 17.1%), overlap myositis (OM; 10.7%), and other IIM (8.6%), were linked to WA cancer and death registries for the period of 1980 to 2014. Cancer incidence rates (CIRs) before and after IIM diagnosis as well as cancer mortality were compared with age-, sex-, and calendar year-matched controls (n = 3225, 54.9% female, median age 64 yrs) by rate ratios (RRs) and Kaplan-Meier survival estimates. RESULTS: The prediagnosis CIR was similar for patients with IIM and controls (6.57 vs 5.95; RR 1.11, 95% CI 0.88-1.39) and for patients evolving to DM (n = 220) or other IIM subtypes (6.59 vs 6.56; RR 1.01, 95% CI 0.38-3.69). During follow-up, CIR was higher for all DM (4.05, 95% CI 3.04-5.29), with increased CIR for lung cancer vs controls (1.05 vs 0.33; RR 3.18, 95% CI 1.71-5.47). Cancer post diagnosis shortened life span by 59 months for patients with IIM (103 vs 162 months, P < 0.01), but reduced survival rates were observed only in patients with DM and IBM. CONCLUSION: Cancer risk was not increased prior to IIM, but CIR for lung cancer was increased following DM diagnosis. As cancer reduced survival only in patients with DM and IBM, these data support a strategy of limited cancer screening in IIM.

A bibliometric analysis of the research status and trends in studies on polymyositis and dermatomyositis with interstitial lung disease from 2000 to 2022 using Web of Science.

BACKGROUND: The main subtypes of idiopathic inflammatory myopathies (IIMs)-polymyositis (PM) and dermatomyositis (DM)-are often presented as interstitial lung disease (ILD) in clinical practice; therefore, many researchers have combined the three studies into PM/DM with ILD. METHODS: Using bibliometrics, the research status, progress, and hotspots of PM/DM with ILD between 2000 and 2022 were studied. Literature data on PM/DM with ILD were retrieved from the Web of Science (WoS) database for the research period. Visualization software, including VOSviewer, Pajek, CiteSpace, and Scimago Graphica were used for bibliometric analysis. RESULTS: A total of 1555 relevant articles were obtained, and the overall research in this field showed an increasing trend. Regarding contributing countries and venues, Japan published the most articles while Rheumatology was the most prolific journal. Regarding authors, the most published article was by Wang Guochun from Changchun University of Technology in China. Keyword analysis and cocited literature cluster analysis showed that diagnosis, classification, autoantibodies, antibodies, prognosis, complications, and treatment of PM/DM with ILD have been hot topics in this field recently. Moreover, our study shows that anti-mda5 antibody, mortality, gene 5 antibody, IIMs, double-blind, and prognostic factors, among others, may be new hot topics. CONCLUSION: This study found that research on PM/DM with ILD has increased over time, and scholars are paying more attention to this field. The development of new drugs for the management, treatment, and prevention of PM/DM with ILD is the primary task of researchers and a direction for future research in this field.

Calcinosis in Juvenile Dermatomyositis-Epidemiology, Pathogenesis, Clinical Features, and Treatment: A Systematic Review.

PURPOSE OF REVIEW: We performed a systematic review of the literature on the epidemiology, pathogenesis, clinical and laboratory characterization, and treatment of calcinosis in patients with juvenile dermatomyositis (JDM). A qualitative systematic review was conducted from January 1975 to April 2023 according to the PRISMA protocol using three electronic databases: PubMed, Web of Science, and Scopus. Studies were analyzed based on the following eligibility criteria: at least one combination of the terms described in the search strategy appeared in the title, written in English, Portuguese, or Spanish, and addressed the epidemiology, pathogenesis, diagnosis, and treatment of calcinosis in juvenile dermatomyositis. Systematic or scoping reviews, letters, clinical images, book chapters, abstracts, inflammatory myopathy in other connective tissue diseases, idiopathic inflammatory myopathies in adults, and purely qualitative studies were excluded. RECENT FINDINGS: Seventy-five studies were included. According to the literature, calcinosis is common in women, around five years old, with three years of disease in association with osteoarticular, cutaneous, pulmonary manifestations, and fever. The pathogenesis is still unknown, but the participation of interleukin 1 and 6, tumor necrosis factor alpha, and innate immunity dysregulation seem to be involved. Common autoantibodies are anti-NXP-2, anti-MDA-5, and anti-Mi-2, and their treatment remains controversial. Prospective, randomized, controlled studies are needed to evaluate treatment protocols and map the natural history of this serious complication. Calcinosis seems to be more common in White female children with muscle weakness, fever, arthritis, severe pulmonary, and skin involvement with anti-NXP-2, anti-MDA-5, and anti-Mi-2 autoantibodies. The multitargets and aggressive treatment is recommended.

Dermatomyositis in Association With SARS-CoV-2 Infection or COVID-19 Vaccine.

OBJECTIVE: New-onset and relapsed dermatomyositis (DM) has been reported following SARS-CoV-2 infection or COVID-19 vaccination. This study aims to show the characteristics of a DM cohort after COVID-19 infection and vaccination. METHODS: A retrospective review was performed on patients treated for DM between March 1, 2020, and October 31, 2022. Charts were evaluated for the presence of new-onset DM or relapse of preexisting DM following either SARS-CoV-2 infection or COVID-19 vaccination. Data on symptom onset, timing of vaccination, type of vaccination, and disease characteristics were collected. RESULTS: Ninety-eight patients treated for DM at our institution in the Division of Rheumatology were included. In total, 12 of 98 patients (12.2%) experienced DM symptoms (either incident or relapse) following either infection or vaccination. Of the 12 patients who developed incident disease or relapse, 7 (58.3%) developed postinfection symptoms, and 8 (66.7%) developed symptoms after vaccination (3 patients had symptoms following both infection and vaccination). The mean onset of symptoms following COVID-19 infection was 3.2 days (median 0.5 days), and mean onset following COVID-19 vaccination was 5.75 days (median 3.5 days). Nine of 12 patients (75%) had a positive myositis-specific antibody, and the remaining 3 (25%) had myositis-associated antibodies. There was no predominant vaccine associated with the development of postvaccination DM symptoms. CONCLUSION: This retrospective review revealed a strong temporal relationship between DM symptoms and COVID-19 infection or vaccination in 12.2% of all patients with DM evaluated in our clinic during the pandemic. Additional studies are required to understand the possible pathophysiology behind this association.

Obesity is an independent risk factor for cancer development following diagnosis of dermatomyositis.

Patients with dermatomyositis (DM) are at an increased risk of cancer development, especially around the time of diagnosis of DM. Obesity is also a risk factor in the general population for cancer development. This study aimed to assess the association between cancer in DM patients with and without obesity as defined by ICD code and BMI data. In this analysis of patients with DM, logistic regression modeling of the odds of cancer outcome was performed for patients with DM and obesity compared to those without obesity, adjusted for age and sex. A total of 12,722 patients with DM were identified, of whom 6,055 had available BMI data. DM patients who were coded obese at any point had significantly higher odds 1.98 (95 % Confidence interval (CI) 1.70, 2.30) of a subsequent cancer diagnosis. This association was also found in the subgroup analysis with available BMI where patients with obesity (BMI ≥30 kg/m2) had an increased odds of cancer 1.23 (1.02, 1.49) when compared to patients with BMI <30 kg/m2 with DM. In time to event analysis any obesity code was associated with a 16 % increased hazard of cancer (adjusted hazard ratio 1.16 [95 % CI 1.02, 1.31]). Overall, the most frequent type of cancer was breast cancer, however patients with DM and obesity had higher frequencies of lymphoma, colorectal, melanoma, uterine, renal cancers compared to patients with DM without obesity.

Gender differences in patients with anti-MDA5-positive dermatomyositis: a cohort study of 251 cases.

OBJECTIVE: To investigate the impact of sex differences on the clinical characteristics and prognosis of patients with anti-melanoma differentiation-associated gene 5-positive dermatomyositis (MDA5+ DM). METHODS: We retrospectively analyzed a cohort of 251 patients with MDA5+ DM, including 71 in the male group and 180 in the female group. A multivariate logistic regression model was built to analyze independent risk factors for RPILD in each group. An ROC curve was drawn to evaluate the predictive value of independent risk factors. Kaplan‒Meier analysis was used to compare the cumulative survival rates, while the log-rank test was used to test for significant differences between the two groups. RESULTS: Patients in the male group had a significantly higher prevalence of heliotrope rash, V sign, severe interstitial lung disease (ILD), and rapidly progressive interstitial lung disease (RPILD) than those in the female group. Anti-Ro52 positivity, high CRP level and short disease were identified as independent risk factors for RPILD in both male and female groups by multivariate logistic regression analysis. The mortality rates of males and females were 33.8% and 22.0%, respectively, and the survival time of patients in the male group was shorter than that in the female group. CONCLUSION: Male patients with MDA5+ DM exhibit an increased risk of RPILD, elevated mortality rates and reduced overall survival time compared to their female counterparts, and anti-Ro52 positivity may be an unfavorable prognostic factor for these patients. Key Points • The prevalence of solar rash, V sign, severe interstitial lung disease (ILD) and rapidly progressive interstitial lung disease (RPILD) in anti-MDA5-positive female patients was significantly lower than that in male patients. • Positive Anti-Ro52, high CRP level, and short course of disease were independent risk factors for RPILD in both men and women. • Female patients exhibited a lower mortality rate than male patients (22.0% vs 33.8%) and demonstrated longer survival time.

Clinical nomogram assisting in discrimination of juvenile dermatomyositis-associated interstitial lung disease.

OBJECTIVE: To establish a prediction model using non-invasive clinical features for early discrimination of DM-ILD in clinical practice. METHOD: Clinical data of pediatric patients with JDM were retrospectively analyzed using machine learning techniques. The early discrimination model for JDM-ILD was established within a patient cohort diagnosed with JDM at a children's hospital between June 2015 and October 2022. RESULTS: A total of 93 children were included in the study, with the cohort divided into a discovery cohort (n = 58) and a validation cohort (n = 35). Univariate and multivariate analyses identified factors associated with JDM-ILD, including higher ESR (OR, 3.58; 95% CI 1.21-11.19, P = 0.023), higher IL-10 levels (OR, 1.19; 95% CI, 1.02-1.41, P = 0.038), positivity for MDA-5 antibodies (OR, 5.47; 95% CI, 1.11-33.43, P = 0.045). A nomogram was developed for risk prediction, demonstrating favorable discrimination in both the discovery cohort (AUC, 0.736; 95% CI, 0.582-0.868) and the validation cohort (AUC, 0.792; 95% CI, 0.585-0.930). Higher nomogram scores were significantly associated with an elevated risk of disease progression in both the discovery cohort (P = 0.045) and the validation cohort (P = 0.017). CONCLUSION: The nomogram based on the ESIM predictive model provides valuable guidance for the clinical evaluation and long-term prognosis prediction of JDM-ILD.

Characteristics and risk of interstitial lung disease in dermatomyositis and polymyositis: a retrospective cohort study in Japan.

Dermatomyositis and polymyositis are rare, idiopathic inflammatory myopathies. Interstitial lung disease is one of the most common and potentially severe extra-muscular manifestations of dermatomyositis and polymyositis and is strongly linked to poor prognosis and early mortality. We aimed to characterise the demographic and clinical characteristics, incidence, and treatment of interstitial lung disease in patients with dermatomyositis or polymyositis. We conducted a retrospective cohort study using the Japan Medical Data Center healthcare claims database. Patients in the database with dermatomyositis (International Classification of Disease version 10 M33.0, M33.1, M33.9) or polymyositis (M33.2) from 01-Jan-2011 until 31-Dec-2019 were identified and followed-up for interstitial lung disease (J84.x) until death, dis-enrolment, or study end (31 December 2020). Cumulative risk curves compared interstitial lung disease risk in dermatomyositis versus polymyositis. Risk factors were evaluated by Cox proportional hazard models. There were 886 patients with dermatomyositis and 745 patients with polymyositis included in the cohort analysis. Mean (standard deviation) age at dermatomyositis/polymyositis diagnosis was 46.0 (16.0)/49.7 (13.3) years and 300 (34%)/104 (14%) developed interstitial lung disease during follow-up. The incidence rate of interstitial lung disease per 100 person-years was 18.42 (95% CI 16.42-20.59) for dermatomyositis and 5.39 (95% CI 4.43-6.50) for polymyositis. In the analysis adjusted for sex, age, and comorbidity score, the risk of interstitial lung disease was significantly higher in patients with dermatomyositis than with polymyositis (hazard ratio 2.72, 95% CI 2.18-3.41). The rate diverged markedly between the groups in the first year after diagnosis. Risk factors for interstitial lung disease were older age in dermatomyositis, female sex and rheumatoid arthritis in polymyositis. Glucocorticoids with/without tacrolimus were the most common newly prescribed drugs after the interstitial lung disease diagnosis. In conclusion, the risk of developing interstitial lung disease was significantly higher in patients with dermatomyositis than with polymyositis, and risk factors were different in the 2 patient groups.

Serum uric acid is independently associated with hypertension in patients with polymyositis and dermatomyositis.

Serum uric acid (UA), as an antioxidant, has been associated with hypertension in the general population. Hypertension is highly prevalent in patients with polymyositis and dermatomyositis (PM/DM). Owning elevated levels of reactive oxygen species, patients with PM/DM have lower concentrations of UA in comparison with healthy people. We explored a potential association between UA levels and hypertension in PM/DM and evaluated whether this association is independent of hypertension risk factors, PM/DM characteristics and relevant drugs. A total of 472 PM/DM patients were assessed. UA and related laboratory data were measured. Demographic, hypertension-related factors, PM/DM characteristics and drug use were assessed as potential covariates. Results were analyzed using logistic models to test the independence of the association between UA and hypertension. UA levels were higher in hypertension subjects compared to non-hypertensive PM/DM patients [284.70 (239.93-357.38) vs 264.00(222.50-322.75), p = .017]. When adjusted for hypertension risk factors, PM/DM characteristics and drugs, the odds of being a hypertensive PM/DM patient per 1 µmol/L UA increase were significantly increased: odds ratio = 1.473 (95% confidence interval:1.063-2.042, p = .020). This cross-sectional study suggests that UA levels are independently associated with hypertension in PM/DM patients.

Incidence and prevalence, and medication use among adults living with dermatomyositis: an Alberta, Canada population-based cohort study.

Dermatomyositis is a rare disease characterized by progressive muscle weakness and skin rashes. Estimates of incidence and prevalence are fundamental measures in epidemiology, but few studies have been conducted on dermatomyositis. To address this knowledge gap, we conducted a population-based study to determine the contemporary incidence (between 2013 and 2019) and prevalence (2019) of adults living with dermatomyositis using administrative health data in Alberta, Canada. We also described disease-related medication use, as there are very few approved medications for the treatment of dermatomyositis, and no Canadian therapeutic guidelines. The average age- and sex-standardized annual incidence of dermatomyositis was 2.8-3.0 cases per 100,000 adults, and prevalence was 28.6 cases per 100,000 adults, which is greater than reported in other cohorts. Dermatomyositis-related medication use decreased from 73% in the first year to 46% in the eighth year after diagnosis. Glucocorticoids were the most commonly used drug class, often taken concurrently with various immunomodulatory agents; this medication use aligns with empirically-based recommendations and the few therapeutic guidelines for dermatomyositis. Considering that Alberta may have one of the highest rates of dermatomyositis among adults, further research on the burden of disease is warranted for planning within the health care system.

Climate change and daily outpatient visits for dermatomyositis in Hefei, China: a time-series study.

With the deepening of research on the correlation between meteorological factors and autoimmune diseases, the relationship between climate change and dermatomyositis (DM) has come to our attention. This study aimed to explore the short-term correlation between meteorological factors and DM outpatient visits. Daily records of hospital outpatient visits for DM, air pollutants, and meteorological factor data in Hefei from January 1, 2018 to December 31, 2021 were obtained. The mean temperature (MT), relative humidity (RH), diurnal temperature range (DTR), and temperature change between neighboring days (TCN) were used to quantify environmental temperature and humidity and their variations. And we performed a time series analysis using a generalized linear model (GLM) in combination with a distributed lag nonlinear model (DLNM). Furthermore, gender and age were further stratified for the analysis. The sensitivity analysis was also performed. A total of 4028 DM outpatient visits were recorded during this period. There were statistically significant associations of low temperature (5th, 1.5 °C), low RH (1st, 48.6%), high RH (99th, 99%), high DTR (75th, 12.6°c), and low TCN (10th, -2.7 °C) that were associated with risk of DM outpatient visits, with lag days of 30, 16, 16, 10, and 14, respectively. Moreover, women were more susceptible to high RH exposure and low TCN exposure, while the elderly were more susceptible to low temperature. This study concluded that exposure to low temperature, extreme RH, and temperature changes (especially high DTR and low TCN) was associated with an increased risk of DM outpatient visits.

Polymyositis/dermatomyositis readmissions: analysis of the nationwide readmission database.

BACKGROUND: There is a scarcity of national population-based studies on polymyositis (PM)/dermatomyositis (DM) readmissions in the USA. In this study, we aim to describe the rates, reasons for readmissions, and characteristics of readmissions for adults hospitalized for PM/DM in the USA. METHODS: We analyzed the 2018 Nationwide Readmissions Database (NRD). We included index hospitalizations for all adult DM/PM patients with a principal diagnosis of PM/DM using ICD-10 codes. We excluded elective and traumatic readmissions. Using a "rank" command in STATA, the most common specific principal diagnosis of readmissions was outlined. Chi-square tests were used to compare baseline characteristics between readmissions and index hospitalizations. STATA 16 was used for analysis. RESULTS: A total of 1610, 1286, and 842 index hospitalizations with a principal diagnosis of PM/DM, that were discharged alive, were included in the 30-, 90-, and 180-day readmission analysis, respectively. Among these, 193 (12%), 276 (21.5%), and 240 (28.5%) were readmitted within 30, 90, and 180 days, respectively. PM and sepsis were the most common reasons for reasons across the 3 timeframes. 30-day readmissions were responsible for an aggregate of 4.1 million US dollars in total hospital cost and 1518 hospital days in 2018. Compared to index hospitalizations, 30-day readmissions have higher Charlson Comorbidity Index scores, severe-extreme loss of function, obesity, and deep venous thrombosis. CONCLUSION: About a third of PM/DM hospitalized patients are readmitted within 180 days. Readmissions constitute a significant economic burden to the health care system. PM and sepsis are the main reasons for readmissions. Key points • About a third of polymyositis (PM)/dermatomyositis (DM) hospitalized patients are readmitted within 180 days • PM and sepsis are the main reasons for readmissions. • Readmissions of PM/DM Patients constitute a significant economic burden to the health care system. • Compared to index hospitalizations, 30-day readmissions have higher Charlson comorbidity index scores, severe-extreme loss of function, obesity, and deep venous thrombosis.

The Prevalence of Dementia among Dermatomyositis and Polymyositis Patients: A Retrospective Cohort Study.

BACKGROUND: Polymyositis (PM) and dermatomyositis (DM) are inflammatory mediated myopathies characterized by progressive symmetric proximal muscle weakness and associated with extra-muscular involvement. Central nervous system complications are rarely reported with these diseases. OBJECTIVES: To investigate the association between dementia and PM/DM. METHODS: A retrospective cohort study was conducted using a database from Clalit Health Care, the largest health maintenance organization in Israel. Patients with a first recorded diagnosis of PM/DM were included and were compared with age- and sex-matched controls by a ratio of 1:5. The prevalence of dementia among PM/DM patients compared to controls was assessed using a univariate and a multivariable model. Binary logistic regression analysis was conducted to assess the association of different factors with dementia within the PM/DM cohort. RESULTS: The study included 2085 PM/DM cases (17.0%) and 10,193 age- and sex-matched controls (83.0%). During the follow-up time, 36 PM/DM patients were diagnosed with dementia compared to 160 controls, with a univariate hazard ratio (HR) of 1.10 (95% confidence interval [95%CI] 0.77-1.58). Within the PM/DM cohort, significant predictors for the development of dementia included increased age at diagnosis (5 years increment; OR 1.86, 95%CI 1.57-2.21, P < 0.001) and treatment with glucocorticoids (OR 5.40, 95%CI 1.67-17.67, P = 0.005). CONCLUSIONS: In our cohort, inflammatory myopathies were not associated with dementia. Age and treatment with glucocorticoids were associated with dementia. If dementia is diagnosed in patients with inflammatory myopathies, other systemic causes should be investigated.

Clinical and laboratory characteristics of idiopathic inflammatory myositis in Saudi patients: A retrospective study in a single tertiary centre.

OBJECTIVES: Idiopathic inflammatory myositis (IIM) in Saudi patients has been poorly studied owing to the lack of available data. This study aimed to identify the clinical and laboratory features of patients at a single tertiary care center. METHODS: This retrospective study reviewed the medical records of Prince Sultan Military Medical City, Riyadh, Saudi Arabia to collect clinical and laboratory data between December 2022 and February 2017 as follows: age at disease onset, gender, follow-up duration and disease duration; clinical symptoms; laboratory result; presence and type of myositis-specific autoantibody or myositis-associated autoantibody; and type of immunosuppression, presence of malignancy, disease course, and outcome. RESULTS: There were 26 patients with a mean age of 36.16±13.48, and 84.6% were women. The most prevalent form of IIM was dermatomyositis (n=16, 61.5%), and the most affected organ was the skin. weakness was observed in 25 patients (96.2%), and dysphagia was the most common alarm sign (n=10, 38.5%). During follow-up, the creatine kinase level was elevated at the beginning of the disease and then decreased following treatment, with a mean of 277.73 IU/L. Of the total patients, 17 (68%) were positive for anti-nuclear antibody and 5 (19.2%) were positive for anti-Jo-1. CONCLUSION: In our patients, dermatomyositis was the most common form of myositis, and skin manifestations were the most prevalent clinical characteristics. None of the patients developed a malignancy or died.

Association between air pollution exposure and outpatient visits for dermatomyositis in a humid subtropical region of China: a time-series study.

In recent years, a growing number of studies have found that air pollution plays critical roles in the onset and development of autoimmune diseases, but few studies have shown an association between air pollutants and dermatomyositis (DM). We sought to investigate the relationship between short-term exposure to air pollution and outpatient visits for DM and to quantify the burden of DM due to exposure to air pollutants in Hefei, China. Daily records of hospital outpatient visits for DM, air pollutants and meteorological factors data in Hefei from January 1, 2018 to December 31, 2021 were obtained. We used a distributed lag non-linear model (DLNM) in conjunction with a generalized linear model (GLM) to explore the association between air pollution and outpatient visits for DM, and conducted stratified analyses by gender, age and season. Moreover, we used attributable fraction (AF) and attributable number (AN) to reflect the burden of disease. A total of 4028 DM clinic visits were recorded during this period. High concentration nitrogen dioxide (NO2) exposure was associated with increased risk of DM outpatient visits (relative risk (RR) 1.063, 95% confidence interval (CI) 1.015-1.114, lag 0-5). Intriguingly, exposure to high concentration ozone (O3) was associated with reduced risk of outpatient visits for DM (RR 0.974, 95% CI 0. 0.954-0.993, lag 0-6). The results of stratified analyses showed that the cold season (vs. warm season) were more susceptible to outpatient visits for DM associated with NO2 and O3 exposure. In addition, we observed that an increased risk of DM outpatient visits was attributable to high concentration NO2 exposure, while high concentration O3 exposure was associated with a decreased risk of DM outpatient visits. This study provided a scientific basis for the etiology research and health protection of DM.