The causal relationship between sarcoidosis and autoimmune diseases: a bidirectional Mendelian randomization study in FinnGen.

Background: Sarcoidosis has been considered to be associated with many autoimmune diseases (ADs), but the cause-and-effect relationship between these two diseases has not been fully explored. Therefore, the objective of this study is to explore the possible genetic association between sarcoidosis and ADs. Methods: We conducted a bidirectional Mendelian randomization (MR) study using genetic variants associated with ADs and sarcoidosis (4,041 cases and 371,255 controls) from the FinnGen study. The ADs dataset comprised 96,150 cases and 281,127 controls, encompassing 44 distinct types of autoimmune-related diseases. Subsequently, we identified seven diseases within the ADs dataset with a case size exceeding 3,500 and performed subgroup analyses on these specific diseases. Results: The MR evidence supported the causal association of genetic predictors of ADs with an increased risk of sarcoidosis (OR = 1.79, 95% CI = 1.59 to 2.02, P IVW-FE = 1.01 × 10-21), and no reverse causation (OR = 1.05, 95% CI 0.99 to 1.12, P IVW-MRE = 9.88 × 10-2). Furthermore, subgroup analyses indicated that genetic predictors of type 1 diabetes mellitus (T1DM), celiac disease, and inflammatory bowel disease (IBD) were causally linked to an elevated risk of sarcoidosis (All P < 6.25 × 10-3). Conversely, genetic predictors of sarcoidosis showed causal associations with a higher risk of type 1 diabetes mellitus (P < 6.25 × 10-3). Conclusion: The present study established a positive causal relationship between genetic predictors of ADs (e.g. T1DM, celiac disease, and IBD) and the risk of sarcoidosis, with no evidence of reverse causation.

Obstructive Sleep Apnea and Sarcoidosis Interactions.

Obstructive sleep apnea (OSA) is very prevalent in sarcoidosis patients. Sarcoidosis of the upper respiratory tract may affect upper airway patency and increase the risk of OSA. Weight gain due to steroid use, upper airway myopathy due to steroids and sarcoidosis itself, and interstitial lung disease with decreased upper airway patency are other reasons for the higher OSA prevalence seen in sarcoidosis. Several clinical manifestations such as fatigue, hypersomnolence, cognitive deficits, and pulmonary hypertension are common to both OSA and sarcoidosis. Therefore, early screening and treatment for OSA can improve symptoms and overall patient quality of life.

Causal influence of celiac disease on the risk of sarcoidosis: A Mendelian randomization study.

Observational research shows a link between celiac disease (CeD) and sarcoidosis, but the causal link between CeD and sarcoidosis is still unknown. A two-sample Mendelian randomization (MR) study was conducted to ascertain the causal connection between the 2 disorders. In our two-sample MR analysis, we identified independent genetic variants associated with CeD using publicly accessible GWAS data from people of European ancestry. Summary data for sarcoidosis were obtained from the FinnGen Consortium, the UK-Biobank, and a large GWAS dataset. To assess the association between CeD and sarcoidosis, our MR analysis used inverse variance weighted (IVW) as the primary method, incorporating the MR-Egger, weighted median (WM), and MR-PRESSO (outliers test) as a complementary method. In order to ensure that the findings were reliable, several sensitivity analyses were performed. Our study indicated that CeD had a significant causal relationship with sarcoidosis (IVW odds ratio (OR) = 1.13, 95% confidence interval (CI): 1.07-1.20, P = 5.58E-05; WM OR = 1.12, 95% CI: 1.03-1.23, P = 1.03E-02; MR-Egger OR = 1.07, 95% CI: 0.96-1.19, P = 2.20E-01). Additionally, we obtain the same results in the duplicated datasets as well, which makes our results even more reliable. The results of this investigation did not reveal any evidence of horizontal pleiotropy or heterogeneity. Our MR analysis showed a causal effect between CeD and an elevated risk of sarcoidosis. Further study is still needed to confirm the findings and look into the processes underlying these relationships.

Organ involvement in newly diagnosed sarcoidosis patients in the Netherlands: The first large European multicentre prospective study.

BACKGROUND: Clinical presentation and prevalence of organ involvement is highly variable in sarcoidosis and depends on ethnic, genetic and geographical factors. These data are not extensively studied in a Dutch population. AIM: To determine the prevalence of organ involvement and the indication for systemic immunosuppressive therapy in newly diagnosed sarcoidosis patients in the Netherlands. METHODS: Two large Dutch teaching hospitals participated in this prospective cohort study. All adult patients with newly diagnosed sarcoidosis were prospectively included and a standardized work-up was performed. Organ involvement was defined using the WASOG instrument. RESULTS: Between 2015 and 2020, a total of 330 patients were included, 55% were male, mean age was 46 (SD 14) years. Most of them were white (76%). Pulmonary involvement including thoracic lymph node enlargement was present in 316 patients (96%). Pulmonary parenchymal disease was present in 156 patients (47%). Ten patients (3%) had radiological signs of pulmonary fibrosis. Cutaneous sarcoidosis was present in 74 patients (23%). Routine ophthalmological screening revealed uveitis in 29 patients (12%, n = 256)). Cardiac and neurosarcoidosis were diagnosed in respectively five (2%) and six patients (2%). Renal involvement was observed in 11 (3%) patients. Hypercalcaemia and hypercalciuria were observed in 29 (10%) and 48 (26%, n = 182) patients, respectively. Hepatic involvement was found in 6 patients (2%). In 30% of the patients, systemic immunosuppressive treatment was started at diagnosis. CONCLUSIONS: High-risk organ involvement in sarcoidosis is uncommon at diagnosis. Indication for systemic immunosuppressive therapy was present in a minority of patients.

Trends and Disparities in Cardiovascular Death in Sarcoidosis: A Population-Based Retrospective Study in the United States From 1999 to 2020.

BACKGROUND: Despite significant cardiac involvement in sarcoidosis, real-world data on death due to cardiovascular disease among patients with sarcoidosis is not well established. METHODS AND RESULTS: We queried the Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiologic Research database for data on patients with sarcoidosis aged ≥25 years from 1999 to 2020. Diseases of the circulatory system except ischemic heart disease were listed as the underlying cause of death, and sarcoidosis was stated as a contributing cause of death. We calculated age-adjusted mortality rate (AAMR) per 1 million individuals and determined the trends over time by estimating the annual percentage change using the Joinpoint Regression Program. Subgroup analyses were performed on the basis of demographic and geographic factors. In the 22-year study period, 3301 cardiovascular deaths with comorbid sarcoidosis were identified. The AAMR from cardiovascular deaths with comorbid sarcoidosis increased from 0.53 (95% CI, 0.43-0.65) per 1 million individuals in 1999 to 0.87 (95% CI, 0.75-0.98) per 1 million individuals in 2020. Overall, women recorded a higher AAMR compared with men (0.77 [95% CI, 0.74-0.81] versus 0.58 [95% CI, 0.55-0.62]). People with Black ancestry had higher AAMR than people with White ancestry (3.23 [95% CI, 3.07-3.39] versus 0.39 [95% CI, 0.37-0.41]). A higher percentage of death was seen in the age groups of 55 to 64 years in men (23.11%) and women (21.81%), respectively. In terms of US census regions, the South region has the highest AAMR from cardiovascular deaths with comorbid sarcoidosis compared with other regions (0.78 [95% CI, 0.74-0.82]). CONCLUSIONS: The increase of AAMR from cardiovascular deaths with comorbid sarcoidosis and higher cardiovascular mortality rates among adults aged 55 to 64 years highlight the importance of early screening for cardiovascular diseases among patients with sarcoidosis.

Comparison of organ involvement clusters in Black and White American sarcoidosis patients from a prospectively collected patient registry.

BACKGROUND: Due to the heterogeneity of sarcoidosis, there is a need to define clinical phenotypes to allow for tailoring of clinical care and identification of more homogenous populations to facilitate research. METHODS: We utilized data from a prospectively collected registry of sarcoidosis patients seen at a single quaternary referral center between January 2019 and February 2021. We used multiple correspondence analysis (MCA) and k-means clustering to investigate if the clusters previously identified in the GenPhenReSa study were reproducible in a US population. We also investigated if these clusters were stable when the population was stratified by race. RESULTS: We replicated 3 of the 5 clusters seen in the GenPhenReSa study in our cohort. We likewise identified similar clusters between White and Black patients with sarcoidosis. Differences in organ manifestations associations between White and Black patients were seen primarily in relation to cardiac, neurologic, and ocular involvement. CONCLUSIONS: The organ clusters of liver-spleen, isolated pulmonary, and musculoskeletal-skin were reproducible in a US cohort, and in both Black and White patients.

Role of screening for uveitis in subjects with sarcoidosis.

BACKGROUND AND OBJECTIVES: Ocular involvement is common in sarcoidosis. Our study aimed to evaluate the role of screening for uveitis in subjects with sarcoidosis. METHODS: Retrospective case series of 88 subjects with a pre-existing diagnosis of sarcoidosis, with no previous diagnosis of uveitis, reviewed by Ophthalmology at Auckland District Health Board between January 2016 and May 2022. RESULTS: Among those undergoing a screening examination, uveitis was observed in 27.8% (15 out of 54 subjects). In those presenting with acute eye symptoms, uveitis was observed in 94.1% (32 out of 34 subjects). Sarcoid uveitis was diagnosed in a total of 50 out of 88 subjects (56.8%). 45 subjects required ocular treatment. Sarcoid uveitis was observed in 6 out of 27 subjects (22.2%) who were entirely asymptomatic at screening. On multivariate analysis, blurring of vision (OR 26.2 p < 0.001), eye pain (OR 7.3 p = 0.014) and respiratory disease (OR 7.1 p = 0.044) were associated with increased risk of sarcoid uveitis. In the 41 subjects with no uveitis at initial examination, 3 subjects (7.3%) subsequently developed uveitis. CONCLUSION: Our study highlights the importance of ophthalmic screening of all patients with systemic sarcoidosis, even in asymptomatic patients. With a high correlation of ocular symptoms in diagnosis of sarcoid uveitis, ophthalmologists should educate patients to look out for the development of symptoms of ocular inflammation, and clinicians who continue follow up for systemic sarcoidosis should remind patients to watch carefully for these symptoms to facilitate timely diagnosis and intervention.

Diagnostic and management strategies in cardiac sarcoidosis.

Cardiac sarcoidosis (CS) is increasingly recognized in the context of with otherwise unexplained electrical or structural heart disease due to improved diagnostic tools and awareness. Therefore, clinicians require improved understanding of this rare but fatal disease to care for these patients. The cardinal features of CS, include arrhythmias, atrio-ventricular conduction delay and cardiomyopathy. In addition to treatments tailored to these cardiac manifestations, immunosuppression plays a key role in active CS management. However, clinical trial and consensus guidelines are limited to guide the use of immunosuppression in these patients. This review aims to provide a practical overview to the current diagnostic challenges, treatment approach, and future opportunities in the field of CS.

Racial disparities among patients with cardiac sarcoidosis and arrhythmias in the United States: A propensity matched-analysis from the national inpatient sample database 2016-2020.

BACKGROUND: Cardiac sarcoidosis (CS) is frequently associated with conduction abnormalities and arrhythmias. In this study, we aim to evaluate racial disparities in the frequency of arrhythmias, and associated co-morbidities, among patients with CS. METHODS: White and African American (AA) patients diagnosed with CS were identified and compared from the 2016-2020 National Inpatient Sample (NIS) database whilst adjusting for confounders via logistic regression models. RESULTS: A total of 7,935 patients with CS were included in the study. The propensity-matched sample comprised of 5,570 patients, of whom 2,785 were White and 2,785 were AA. AA patients had a longer mean length of hospital stay (LOS) (7.84 vs. 6.94, p<0.01), a higher mean Charlson Comorbidity Index (CCI) score (3.10 vs. 2.84, p<0.01), and significantly higher incidences of cardiogenic shock [(9.2% vs 6.3%, p<0.01), aOR 1.45 (95% CI 1.17-1.78), p<0.01] and acute kidney injury (AKI) [(34.3% vs. 26.9%, p<0.01), aOR 1.41 (95% CI 1.24-1.61), p<0.01]. From an arrhythmia perspective, AA CS patients were shown to have a lower frequency of: (1) ventricular tachycardia (32.5% vs. 37.9%, p<0.01), (2) ventricular fibrillation (5.4% vs.7.2%, p<0.01), (3) first-degree AV block (1.8% vs. 4.1%, p<0.01), (4) complete AV block (6.3% vs. 14.2%, p<0.01), and (5) atrial fibrillation (31.8% vs. 34.8%, p=0.016) when compared to Whites with CS. Mortality remained higher for AAs (3.8% vs. 2.7%, p=0.024). CONCLUSION: Our study demonstrates a higher incidence of cardiac arrhythmias among White patients but a higher incidence of cardiogenic shock, AKI, mean LOS, and mortality among AA patients with cardiac sarcoidosis.

Hospitalizations of patients with sarcoidosis before and during the COVID-19 pandemic in Poland.

INTRODUCTION: Sarcoidosis is a multisystemic granulomatous disease that mostly affects the lungs and lymphatic system. Due to its rarity and variable clinical course, analyses of factors related to sarcoidosis should be based on large databases and long observation periods. OBJECTIVES: The aim of this study was to determine the characteristics of patients with sarcoidosis hospitalized in Poland over a long period (2016-2021). PATIENTS AND METHODS: We conducted a retrospective study using hospital discharge records compiled by the National Institute of Public Health NIH - National Research Institute. We analyzed the records of patients with sarcoidosis from the entire Polish population at their first hospitalization. RESULTS: We identified a total of 15 548 first-time hospitalizations for sarcoidosis. The mean annual disease incidence was 6.8 cases per 100 000. The mean (SD) age of the patients was 45.8 (13.6) years, and it was lower in men than in women (42.9 [12.5] vs 49.8 [14.2] years; P <0.001). There were significantly more hospitalizations among city dwellers (62.3% vs 37.3% for rural residents; P <0.001). At the beginning of the COVID­19 pandemic in Poland there was a decrease in the number of hospitalizations for sarcoidosis, followed by an increase in the subsequent year. The all­cause in­hospital death rate was significantly higher during the COVID­19 pandemic, as compared with the period before the pandemic (7.2 vs 2.3 per 1000; P <0.001). CONCLUSIONS: Health care changes related to the outbreak of the COVID­19 pandemic may have increased the health debt for inpatient sarcoidosis treatment. The occurrence of sarcoidosis in Poland may be related to demographic and territorial factors.

Blood glucose and lipids are associated with sarcoidosis: findings from observational and mendelian randomization studies.

BACKGROUND: Several researches have demonstrated that patients with sarcoidosis accompanied with the abnormality in blood glucose and/or lipids, however, the causal relationship between them remains uncertain. To elucidate the potential association and causality of blood glucose and lipids with sarcoidosis, we conducted a propensity score matching (PSM)-based observational study combined with mendelian randomization (MR) analysis. METHODS: All subjects in this study were retrospectively collected from Tongji Hospital during 2010 and 2023. 1:1 PSM was employed to control the potential confounders as appropriate. Univariable and multivariable logistic regression analyses were performed to estimate the associations of sarcoidosis with fasting glucose, high density lipoprotein cholesterol (HDLC), low density lipoprotein cholesterol (LDLC), total cholesterol (TC), and total triglyceride (TG). The further subtype analysis was also conducted. Afterwards, a bidirectional MR analysis based on public data deeply explored the causality among the 5 candidate traits and sarcoidosis, for which the inverse-variance weighted (IVW) method was utilized as the main inferring approach. RESULTS: In the observational study, a total number of 756 subjects were enrolled, with 162 sarcoidosis patients and 594 non-sarcoidosis participants, while 160 pairs of subjects were matched after PSM. Multivariable logistic regression analysis indicated that HDLC (OR: 0.151; 95% CI: 0.056-0.408; P < 0.001) and TC (OR: 3.942; 95% CI: 2.644-5.877; P < 0.001) were strongly associated with sarcoidosis. Subtype analysis showed that low HDLC was independently correlated to risk of lesions in bronchus and lungs, and mediastinal lymph nodes, while high TC was to cervical lymph nodes. In MR analysis, high fasting glucose, low HDLC, and high TC were identified as the causal factors of sarcoidosis. CONCLUSION: HDLC and TC had the potential to influence the risk of sarcoidosis, which could be regarded as predictors and may provide new diagnostic and therapeutic targets for sarcoidosis.

Diagnostics, treatment and outcomes of cardiac sarcoidosis in a Norwegian cohort.

BACKGROUND: Evidence-based guidelines for cardiac sarcoidosis (CS) regarding use of second- and third-line agents, treatment duration, surveillance and prognostic factors are lacking. OBJECTIVE: To analyze the clinical presentation, diagnostics, treatment, monitoring and clinical outcomes in a Norwegian cohort. METHODS: Using discharge diagnoses between 2017 through 2020 from a large tertiary center, we identified 52 patients with CS. We performed a systematic chart review following a pre-specified checklist. The primary outcome of major cardiovascular events (MACE) was defined as a composite of cardiovascular hospitalization, defibrillator therapy, cardiac transplantation, or death. RESULTS: 18-fluorodeoxyglucose positron emission tomography (FDG-PET) showed pathological tracer uptake in 35/36 (97%) of immunosuppression-naïve patients. Immunosuppressive treatment was administered to 49/52 patients (94%) for a median of 43 (IQR 34) months; 69% were treated with second-line (methotrexate, azathioprine, mycophenolate mofetil) and 25% with third-line (rituximab, infliximab) agents, respectively. Rituximab reduced inflammation as assessed by interval FDG-PET imaging and was overall well tolerated. Median duration to first MACE was 6 (IQR 10) months and 17/23 patients (74%) experienced a MACE within 12 months from CS diagnosis. No mortality was recorded and 20% achieved full remission. Age below the median of 53 years at time of diagnosis was associated with an increased risk of a MACE. CONCLUSION: Long-term immunosuppression including a liberal use of non-steroidal agents, appeared essential in treating CS. Although the burden of cardiovascular events was substantial, the survival was excellent in this contemporary cohort. Prospective randomized studies are urgently needed to define the best therapy for these patients.

Menopausal hormone therapy and risk of sarcoidosis: a population-based nested case-control study in Sweden.

Sarcoidosis incidence peaks in women between 50 and 60 years old, which coincides with menopause, suggesting that certain sex hormones, mainly estrogen, may play a role in disease development. We investigated whether menopausal hormone therapy (MHT) was associated with sarcoidosis risk in women and whether the risk varied by treatment type. We performed a nested case-control study (2007-2020) including incident sarcoidosis cases from the Swedish National Patient Register (n = 2593) and matched (1:10) to general population controls (n = 20,003) on birth year, county, and living in Sweden at the time of sarcoidosis diagnosis. Dispensations of MHT were obtained from the Swedish Prescribed Drug Register before sarcoidosis diagnosis/matching. Adjusted odds ratios (aOR) of sarcoidosis were estimated using conditional logistic regression. Ever MHT use was associated with a 25% higher risk of sarcoidosis compared with never use (aOR 1.25, 95% CI 1.13-1.38). When MHT type and route of administration were considered together, systemic estrogen was associated with the highest risk of sarcoidosis (aOR 1.51, 95% CI 1.23-1.85), followed by local estrogen (aOR 1.25, 95% CI 1.11-1.42), while systemic estrogen-progestogen combined was associated with the lowest risk compared to never users (aOR 1.12, 95% CI 0.96-1.31). The aOR of sarcoidosis did not differ greatly by duration of MHT use. Our findings suggest that a history of MHT use is associated with increased risk of sarcoidosis, with women receiving estrogen administered systemically having the highest risk.

Epidemiology of Sarcoidosis.

Sarcoidosis is a systemic, granulomatous disease with variable presentation earning it the term "the great mimicker." The current epidemiology confirms that the disease occurs worldwide, affecting both sexes, and all races, ethnicities, and ages. To date, no causal exposure or agent has been identified. The organ systems most frequently affected by sarcoidosis are also those with greatest exposure to the natural world suggesting environmental and lifestyle contributions to the disease. These include particulate matter, microorganisms, nicotine, and obesity. In this article, we review the epidemiology of sarcoidosis and discuss these non-genetic risk factors in the hope of providing important insight into sarcoidosis and stimulating future research.

Clinical characteristics and prognosis of patients with isolated cardiac sarcoidosis: Insights from the ILLUMINATE-CS study.

AIM: Data on the clinical features and prognosis of patients with isolated cardiac sarcoidosis (iCS) are limited. This study evaluated the clinical characteristics and prognostic impact of iCS. METHODS AND RESULTS: This was a secondary analysis of the ILLUMINATE-CS study, a multicentre, retrospective registry investigating the clinical characteristics and prognosis of cardiac sarcoidosis. iCS was diagnosed according to the 2016 Japanese Circulation Society (JCS) guidelines. Clinical characteristics and prognosis were compared between patients with iCS and systemic cardiac sarcoidosis (sCS). The primary outcome was a combined endpoint of all-cause death, hospitalization for heart failure, or fatal ventricular arrhythmia events. Among 475 patients with CS (mean age, 62.0 ± 10.9 years; female ratio, 59%) diagnosed by the JCS guidelines, 119 (25.1%) were diagnosed with iCS. Patients with iCS had a higher prevalence of a history of atrial fibrillation or hospitalization for heart failure, or lower left ventricular ejection fraction than those with sCS. During a median follow-up of 42.3 (interquartile range, 22.8-72.5) months, 141 primary outcomes (29.7%) occurred. Cox proportional hazard analysis revealed that iCS was a significant risk factor for the primary outcome in the unadjusted model (hazard ratio [HR] 1.62; 95% confidence interval [CI] 1.12-2.34; p = 0.011). However, this association was not retained after adjustment for other covariates (adjusted HR 1.27; 95% CI 0.86-1.88; p = 0.226). CONCLUSIONS: Patients with iCS had more impaired cardiovascular function at the time of diagnosis than those with sCS. However, iCS was not independently associated with poor prognosis after adjustment for prognostic factors.

One-year lung function decline in sarcoidosis.

BACKGROUND: The definition of progressive pulmonary fibrosis is based on a 1-year lung function decline. OBJECTIVES: To evaluate the epidemiology and clinical relevance of 1-year lung function decline in sarcoidosis. METHODS: A retrospective observational study at a general sarcoidosis clinic. RESULTS: Of the 198 patients, 42 (18.4 %) had a 1-year lung function decline (absolute 12-month decline in percentage predicted forced vital capacity [%FVC] of ≥5 % or percentage predicted diffusion capacity for carbon monoxide [%DLCO] of ≥10 %). A 1-year lung function decline was associated with a 2-year lung function decline (a relative 24-month decline in %FVC of ≥10 % or %DLCO of ≥15 %), which occurred in 13 (7.4 %) of the 175 patients with 24-month follow-up results. A 1-year lung function decline was not associated with survival; a 2-year lung function decline predicted mortality. CONCLUSIONS: Compared with a 24-month decline, a 12-month decline in lung function did not predict worse survival in sarcoidosis.

Prevalence of Cardiac Sarcoidosis in Middle-Aged Adults Diagnosed with High-Grade Atrioventricular Block.

INTRODUCTION: Atrioventricular block may be idiopathic or a secondary manifestation of an underlying systemic disease. Cardiac sarcoidosis is a significant underlying cause of high-grade atrioventricular block, posing diagnostic challenges and significant clinical implications. This study aimed to assess the prevalence and clinical characteristics of cardiac sarcoidosis among younger patients presenting with unexplained high-grade atrioventricular block. METHODS: We evaluated patients aged between 18 and 65 years presenting with unexplained high-grade atrioventricular block, who were systematically referred for cardiac magnetic resonance imaging, positron emission tomography-computed tomography, or both, prior to pacemaker implantation. Subjects with suspected cardiac sarcoidosis based on imaging findings were further referred for tissue biopsy. Cardiac sarcoidosis diagnosis was confirmed based on biopsy results. RESULTS: Overall, 30 patients with high-grade atrioventricular block were included in the analysis. The median age was 56.5 years (interquartile range 53-61.75, years). In 37%, cardiac magnetic resonance imaging, positron emission tomography-computed tomography, or both, were suggestive of cardiac sarcoidosis, and in 33% cardiac sarcoidosis was confirmed by tissue biopsy. Compared with idiopathic high-grade atrioventricular block patients, all cardiac sarcoidosis patients were males (100% vs 60%, P = .029), were more likely to present with heart failure symptoms (50% vs 10%, P = .047), had thicker inter-ventricular septum on echocardiography (12.2 ± 2.7 mm vs 9.45 ± 1.6 mm, P = .002), and were more likely to present with right ventricular dysfunction (33% vs 10%, P = .047). CONCLUSIONS: Cardiac sarcoidosis was confirmed in one-third of patients ≤ 65 years, who presented with unexplained high-grade atrioventricular block. Cardiac sarcoidosis should be highly suspected in such patients, particularly in males who present with heart failure symptoms or exhibit thicker inter-ventricular septum and right ventricular dysfunction on echocardiography.

Trends in Hospitalization Duration for Rare Diseases: A Retrospective Analysis of Sarcoidosis, Still's Disease, and Systemic Sclerosis in Poland (2009-2018).

BACKGROUND A rare disease is a health condition that rarely occurs in the population. It is estimated that up to 400 million people around the world suffer from a rare disease. This retrospective study aimed to investigate factors associated with length of hospitalization in 78 626 patients with sarcoidosis, 3294 patients with adults-onset Still's disease, and 35 549 patients with systemic sclerosis between 2009 and 2018 using data from the National Institute of Public Health in Poland. MATERIAL AND METHODS In this population-based study, we analyzed hospital discharge records of first-time and subsequent hospitalizations. To perform the statistical analyses, R software was used. RESULTS The average length of hospitalization over the selected period in the diseases was 5.39 days for sarcoidosis, 6.22 days for scleroderma, and 7.44 days for Still's disease, and was shorter for each of the diseases analyzed compared with the length of hospitalization for second and subsequent stays. There were no substantial differences in length of hospitalization between males and females. The average length of hospitalization increased with each additional comorbidity. CONCLUSIONS The study showed that hospitalizations for selected rare diseases do not cause a significant burden on the healthcare system. The results also showed that advanced age and comorbidities are important factors determining the length of hospitalization. The average length of hospital stay for selected rare diseases in Poland is not longer than the European Union (EU) average, so it can be assumed that the process of inpatient treatment in Poland is optimal.