Hypothyroidism as a risk factor for development of cardiovascular disease in patients with rheumatoid arthritis

Investigating the Bidirectional Association of Rheumatoid Arthritis and Thyroid Function: A Methodologic Assessment of Mendelian Randomization

OBJECTIVE

Rheumatoid arthritis (RA) and thyroid dysfunction are frequently observed in the same patient. However, whether they co-occur or exhibit a causal relationship remains uncertain. We aimed to systematically investigate the causal relationship between RA and thyroid function using a large sample and advanced methods.

METHODS

Bidirectional two-sample Mendelian randomization (MR) analysis was performed based on RA and six thyroid function trait data sets from the European population. The robustness of the results was demonstrated using multiple MR methods and a series of sensitivity analyses. Multivariable MR using Bayesian model averaging (MR-BMA) was performed to adjust for possible competing risk factors. A sensitivity data set, which included data from patients with seropositive RA and controls, was used to repeat the analyses. Furthermore, enrichment analysis was employed to discover the underlying mechanism between RA and thyroid functions.

RESULTS

A significantly positive causal effect was identified for RA on autoimmune thyroid disease (AITD) as well as for AITD on RA (P < 0.001). Further sensitivity analyses showed consistent causal estimates from a variety of MR methods. After removing the outliers, MR-BMA results showed that RA and AITD were independent risk factors in their bidirectional causality, even in the presence of other competing risk factors (adjusted P < 0.05). Enrichment analysis showed immune cell activation and immune response play crucial roles in them.

CONCLUSION

Our results illustrate the significant bidirectional causal effect of RA and AITD, which holds even in multiple competing risk factors. Clinical screening for thyroid dysfunction in patients with RA deserves further attention, and vice versa.

[The effect of hypothyroidism on cardiovascular events and type 2 diabetes mellitus developing in rheumatoid arthritis]

AIM

To compare the frequency of cardiovascular events (CVE), to assess the risk of cardiovascular death using the mSCORE and the development of type 2 diabetes mellitus (DM) using the FINDRISC in patients with rheumatoid arthritis (RA) with and without hypothyroidism.

MATERIALS AND METHODS

The study included 149 patients (125 women, 24 men) with RA (median age - 57 [52; 61] years). In all patients, traditional factors of cardiovascular risk and glucose metabolism disorders (age, smoking status, total blood cholesterol, blood pressure, overweight, abdominal obesity - AO, heredity burdened by diabetes, insufficient physical activity, the lack of the necessary amount of berries, fruits and vegetables in the daily diet, history of hyperglycemia episodes), the 10-year risk of death from cardiovascular causes according to the mSCORE and the risk of developing type 2 DM according to the FINDRISС were assessed, a history of CVE (myocardial infarctions, and its revascularization, stroke) was recorded.

RESULTS

Hypothyroidism was diagnosed in 17.4% of RA patients. Patients with hypothyroidism (group 1) were more likely to have AO and less likely to consume unsufficient dietary fiber than patients with euthyroidism (group 2). Moderate, high and very high risk of development according to the mSCORE and FINDRISC was detected in 61.5% of hypothyroid patients and 48.8% euthyroid patients, according to mSCORE alone - in 30.8 and 44.7%, according to FINDRISC - in 0 and 2.4%, respectively (p>0.05 in all cases); 11.5% of patients in group 1 and 6.5% in group 2 suffered from CVE (OR 1.875, 95% CI 0.462-7.607; p=0.63).

CONCLUSION

It is necessary to evaluate the thyroid gland function, especially in patients with AO due to the high frequency of hypothyroidism in RA. Hypothyroidism did not have an independent effect on the severe CVЕ rates, as well as risk assessment according to the score and FINDRISC in RA patients. Theses, with and without hypothyroidism, were predominantly in the moderate, high, very high risk groups according to both scales.

Factors associated with incident cardiovascular disease in patients with rheumatoid arthritis: A scoping review

INTRODUCTION

Rheumatoid arthritis (RA) is the most common form of autoimmune inflammatory arthritis and is associated with various comorbidities including cardiovascular disease (CVD). This scoping review summarizes the current evidence on longitudinal cohort studies assessing potential factors associated with the incidence of cardiovascular events among patients with RA.

METHODS

Scopus, PubMed, Ovid MEDLINE and Cochrane databases were used to identify longitudinal cohort studies investigating the incidence of CVD among RA patients. Using predetermined inclusion and exclusion criteria, two reviewers screened and extracted the relevant studies independently to map the existing literature on this topic. The extracted data included study characteristics, demographics, comorbidities, behavioural and RA-related factors.

RESULTS

Thirty-three research papers were included with a mean follow-up duration of 7.8 years. The sample size of the studies ranged from 182 to 4,311,022 subjects, the mean age from 46.1 to 72.3 years, and on average, 34.6% of the participants were male. The following factors were reported to be associated with a higher incidence of CVD in RA patients: older age, male sex, co-morbid hypertension, diabetes, and/or dyslipidemia, the presence of rheumatoid factor (RF) and/or acute phase reactants. Among RA treatments, glucocorticoids were shown to increase CVD incidence while DMARDs, especially methotrexate, were associated with a lower incidence of CVD.

CONCLUSION

This review offers a comprehensive summary of the current literature reporting on risk factors for CVD incidence among RA patients. Future research should focus on the less studied factors, including socioeconomic status, physical inactivity, alcohol consumption, sleep habits and dietary patterns as well as some RA-related factors such as anti-citrullinated protein antibodies and functional impairment.

Thyroid function in pediatric patients with juvenile idiopathic arthritis

PURPOSE

Juvenile Idiopathic Arthritis (JIA) is a chronic inflammatory disease characterized by chronic synovitis, sometimes associated with fever, rash, pericarditis and uveitis. Limited data are available concerning autoimmune diseases associated with JIA in childhood.

THE AIMS OF OUR STUDY WERE

(a) evaluating the thyroid function in a group of Italian children affected by JIA; (b) identifying which Autoimmune Thyroid Diseases (ATDs) are related to JIA in this population.

METHODS

A population of 51 patients with JIA was investigated. Each patient enrolled was evaluated clinically (family history for Autoimmune Diseases (ADs), personal history and physical examination). In the sample were evaluated thyroid function, inflammation's index and anti-thyroid antibodies.

RESULTS

The 68.6% (35) of our patients had the oligoarticular form, 27.5% (14) had the polyarticular one, 2% (1) had systemic onset and 2% (1) had undifferentiated arthritis. We focused our attention on the differences between the first two forms. We did not find any difference on the gender prevalence (p > 0.05). A higher presence of anti-TPO antibodies was found in the polyarticular form, with a significant difference with the oligoarticular one (p = 0.032). We researched the anti-hTG antibodies (p > 0.05) and ANA for each group (p > 0.05). We found a significant prevalence of family history for ADs in the polyarticular form (p < 0.05).

CONCLUSION

Our findings show the necessity to focus on thyroid function in patients with JIA. Although the oligoarticular form is the most frequent, the polyarticular form shows a higher frequency of thyroid function's alteration. This suggests the need for specific attention in polyarticular form.

Association between rheumatoid arthritis and autoimmune thyroid disease: evidence from complementary genetic methods

OBJECTIVES

To assess the causal association of Rheumatoid Arthritis (RA) with Autoimmune thyroid disease (AITD).

METHOD

Complementary genetic approaches, including genetic correlation, Mendelian randomization (MR) and colocalization analysis, were conducted to assess the potential causal association between RA and AITD using summary statistics from large-scale genome-wide association studies (GWASs). Various sensitivity analyses had been conducted to assess the robustness and the consistency of the findings.

RESULTS

The linkage disequilibrium score regression revealed a shared genetic structure between RA and AITD, with the significant genetic correlation between RA and autoimmune hyperthyroidism and autoimmune hypothyroidism estimated to be 0.3945 (P = 2.83 × 10-6) and 0.2771 (P = 1.04 × 10-6) respectively. The results of MR analysis showed that RA had a positive causal relationship with autoimmune hypothyroidism and autoimmune hyperthyroidism. The odds ratio (OR) were 1.29 (95% CI, 1.17-1.42; P = 1.08 × 10-7) and 1.47 (95% CI, 1.25-1.72; P = 1.85 × 10-6), respectively. In reverse MR analysis, autoimmune hypothyroidism had a positive causal relationship with RA, OR was 1.51 (95% CI, 1.37-1.66; P = 1.10 × 10-16); autoimmune hyperthyroidism had no causal relationship with RA relationship (P = 0.22). Similar results were found using different MR methods. In addition, colocalization analysis suggested that shared causal variants existed between RA and AITD.

CONCLUSIONS

Our study suggested a potentially causal effect of genetically predicted RA on autoimmune hyperthyroidism and a bidirectional causal relationship between RA and autoimmune hypothyroidism was also observed with complementary genetic approaches, which supports the importance and necessity of thyroid function screening and monitoring in RA patient management in clinical practice.

Autoimmune thyroid disease and rheumatoid arthritis: where the twain meet

Autoimmune thyroid disease (AITD) is the most prevalent autoimmune disease. It shares multiple genetic, clinical, and serologic characteristics with rheumatoid arthritis (RA). Although frequently described as a classic form of single-organ autoimmunity, the AITD disease burden in a subset of patients extends well beyond the thyroid gland. This review explores the complex interaction between the two diseases and the clinical consequences when they overlap. Beyond the well-known effects of AITD on thyroid function in RA, there is mounting evidence of the association of both conditions impacting the presentation and outcomes of diabetes, metabolic syndrome, and cardiovascular disease. An increasing number of studies suggest that there are negative effects of AITD on RA disease activity both in the presence and in the absence of thyroid dysfunction. Recent evidence suggests that AITD may not only worsen the cumulative damage of RA through higher disease activity but may also worsen secondary osteoarthritis changes. Less well-known is the significant association between AITD and chronic widespread pain syndromes including fibromyalgia. Importantly, the presence of fibromyalgia, which is increased in RA patients, appears to be further increased when it overlaps with AITD. Lastly, we probe the possible influence of AITD interacting with RA on fertility and clinical depression. Key Points • Autoimmune thyroid disease is the most common autoimmune disease and is frequently associated with rheumatoid arthritis. • Autoimmune thyroid disease can present with osteoarthritis, inflammatory arthritis, and chronic widespread pain syndromes. • The co-occurrence of autoimmune thyroid disease and rheumatoid arthritis may worsen disease activity and exacerbate other disease manifestations including cardiovascular disease, fertility, and depression. • The overlap of rheumatoid arthritis with autoimmune thyroid disease needs further research and should be sought in general clinical practice.

Investigating the shared genetic architecture between hypothyroidism and rheumatoid arthritis

Background

There is still controversy regarding the relationship between hypothyroidism and rheumatoid arthritis (RA), and there has been a dearth of studies on this association. The purpose of our study was to explore the shared genetic architecture between hypothyroidism and RA.

Methods

Using public genome-wide association studies summary statistics of hypothyroidism and RA, we explored shared genetics between hypothyroidism and RA using linkage disequilibrium score regression, ρ-HESS, Pleiotropic analysis under a composite null hypothesis (PLACO), colocalization analysis, Multi-Trait Analysis of GWAS (MTAG), and transcriptome-wide association study (TWAS), and investigated causal associations using Mendelian randomization (MR).

Results

We found a positive genetic association between hypothyroidism and RA, particularly in local genomic regions. Mendelian randomization analysis suggested a potential causal association of hypothyroidism with RA. Incorporating gene expression data, we observed that the genetic associations between hypothyroidism and RA were enriched in various tissues, including the spleen, lung, small intestine, adipose visceral, and blood. A comprehensive approach integrating PLACO, Bayesian colocalization analysis, MTAG, and TWAS, we successfully identified TYK2, IL2RA, and IRF5 as shared risk genes for both hypothyroidism and RA.

Conclusions

Our investigation unveiled a shared genetic architecture between these two diseases, providing novel insights into the underlying biological mechanisms and establishing a foundation for more effective interventions.

Causal relationship between rheumatoid arthritis and hypothyroidism or hyperthyroidism: a bidirectional two-sample univariable and multivariable Mendelian randomization study

Objective

The causal relationship between Rheumatoid arthritis (RA) and hypothyroidism/hyperthyroidism remains controversial due to the limitations of conventional observational research, such as confounding variables and reverse causality. We aimed to examine the potential causal relationship between RA and hypothyroidism/hyperthyroidism using Mendelian randomization (MR).

Method

We conducted a bidirectional two-sample univariable analysis to investigate the potential causal relationship between hypothyroidism/hyperthyroidism and RA. Furthermore, we performed a multivariate analysis to account for the impact of body mass index (BMI), smoking quantity, and alcohol intake frequency.

Results

The univariable analysis indicated that RA has a causative influence on hypothyroidism (odds ratio [OR]=1.07, 95% confidence interval [CI]=1.01-1.14, P=0.02) and hyperthyroidism (OR=1.32, 95% CI=1.15-1.52, P<0.001). When hypothyroidism/hyperthyroidism was considered as an exposure variable, we only observed a causal relationship between hypothyroidism (OR=1.21, 95% CI=1.05-1.40, P=0.01) and RA, whereas no such connection was found between hyperthyroidism (OR=0.91, 95% CI=0.83-1.01, P=0.07) and RA. In the multivariate MR analyses, after separately and jointly adjusting for the effects of daily smoking quantity, alcohol intake frequency, and BMI, the causal impact of RA on hypothyroidism/hyperthyroidism and hypothyroidism on RA remained robust. However, there is no evidence to suggest a causal effect of hyperthyroidism on the risk of RA (P >0.05).

Conclusion

Univariate and multivariate MR analyses have validated the causal association between RA and hypothyroidism/hyperthyroidism. Hypothyroidism confirmed a causal relationship with RA when employed as an exposure variable, whereas no such relationship was found between hyperthyroidism and RA.

The co-occurrence and cumulative prevalence of hypertension, rheumatoid arthritis, and hypothyroidism in preterm-born women in the Women's Health Initiative

Emerging evidence suggests that preterm-born individuals (<37 weeks gestation) are at increased risk of developing chronic health conditions in adulthood. This study compared the prevalence, co-occurrence, and cumulative prevalence of three female predominant chronic health conditions - hypertension, rheumatoid arthritis [RA], and hypothyroidism - alone and concurrently. Of 82,514 U.S. women aged 50-79 years enrolled in the Women's Health Initiative, 2,303 self-reported being born preterm. Logistic regression was used to analyze the prevalence of each condition at enrollment with birth status (preterm, full term). Multinomial logistic regression models analyzed the association between birth status and each condition alone and concurrently. Outcome variables using the 3 conditions were created to give 8 categories ranging from no disease, each condition alone, two-way combinations, to having all three conditions. The models adjusted for age, race/ethnicity, and sociodemographic, lifestyle, and other health-related risk factors. Women born preterm were significantly more likely to have any one or a combination of the selected conditions. In fully adjusted models for individual conditions, the adjusted odds ratios (aORs) were 1.14 (95% CI, 1.04, 1.26) for hypertension, 1.28 (1.12, 1.47) for RA, and 1.12 (1.01, 1.24) for hypothyroidism. Hypothyroidism and RA were the strongest coexisting conditions [aOR 1.69, 95% CI (1.14, 2.51)], followed by hypertension and RA [aOR 1.48, 95% CI (1.20, 1.82)]. The aOR for all three conditions was 1.69 (1.22, 2.35). Perinatal history is pertinent across the life course. Preventive measures and early identification of risk factors and disease in preterm-born individuals are essential to mitigating adverse health outcomes in adulthood.

Hypothyroidism and rheumatoid arthritis: a two-sample Mendelian randomization study

Background

Meta-analysis of genome-wide association studies (GWAS) data showed that the relationship between hypothyroidism and rheumatoid arthritis (RA) risk remains under debate. This study is conducted to test the causal relationship of hypothyroidism and RA.

Methods

A two-sample Mendelian randomization (TSMR) analysis was employed to estimate the causality of hypothyroidism and rheumatoid arthritis in European ancestry and Asian ancestry. Integrating the effects generated by TSMR, functional annotations and noncoding variant prediction framework were applied to analyze and interpret the functional instrument variants (IVs).

Results

The results of the inverse variance weighted method showed a strong significant causal relationship between hypothyroidism and risk of RA in European ancestry [odds ratio (OR) = 1.96; 95% confidence interval (CI) 1.49, 2.58; p < 0.001]. The outcomes of MR-Egger, weighted median, weighted mode, and simple mode also showed that hypothyroidism was significantly associated with increased risk of RA in European ancestry. The MR-PRESSO method also showed significant results [Outlier-corrected Causal Estimate = 0.70; standard error (SE) = 0.06; p < 0.001]. An independent dataset and an Asian ancestry dataset were applied to estimate and obtain the coincident results. Furthermore, we integrated the effect of variants in TSMR analysis, functional annotations, and prediction methods to pinpoint the single-nucleotide polymorphism (SNP) rs4409785 as one of the causal variants, which suggested that this variant could impact the binding of CTCF-cohesin and play a vital role in immune cells.

Conclusion

In this study, we prove that hypothyroidism is significantly causally associated with increased RA risk, which has not been shown in previous studies. Furthermore, we pinpoint the potential causal variants in RA.

The prevalence of thyroid dysfunction and autoimmune thyroid disease in patients with rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is one of the most common chronic non-organ-specific autoimmune diseases; meanwhile, autoimmune thyroid disease (AITD) is the most common organ-specific autoimmune disease that can lead to hypo or hyperthyroidism. Although the etiology of both diseases is complex with a combination of genetic and environmental factors, there are overlaps in genes contributing to the pathogenesis of both diseases. Numerous studies found a correlation between thyroid abnormality and RA in different populations, yet some didn’t. This study is aimed to evaluate the prevalence of thyroid dysfunction, AITD, and anti-thyroid peroxidase (anti-TPO) positively in Iranian patients with RA.

Methods

A total of 250 RA patients and 248 patients with non-inflammatory rheumatologic disease were included in this case–control study. All participants underwent complete clinical and laboratory assessments. Participants were also assessed for thyroid function testing, including anti-TPO antibodies.

Results

Thyroid dysfunction was twice as common in RA patients as in controls (OR = 2.16; P-value > 0.001). Overt hypothyroidism was the most common thyroid dysfunction among RA patients (58 out of 84). Anti-TPO positivity was also significantly more common in RA compared with controls (OR = 2.65; P-value > 0.001). The proportion of controls and RA patients with AITD were 9 and 21.5%, respectively. AITD was found 2.8 times more common in RA group than controls (OR = 2.77; P-value > 0.001).

Conclusion

It was demonstrated that RA was an independent factor associated with thyroid dysfunction and AITD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-022-00293-9.

Prevalence, Clinical Manifestations, and Treatment Pattern of Patients with Rheumatoid Arthritis Attending the Rheumatology Clinic at Tikur Anbessa Specialized Hospital, Ethiopia: A Cross-Sectional Study

Background

Rheumatoid arthritis (RA) is an a chronic inflammatory disease characterized by symmetric polyarticular inflammation that can lead to progressive joint damage. It is said to be rare among black Africans, even though there have been limited reports from some African countries and no study has been done on RA in Ethiopia. This study determined the prevalence, clinical features, and treatment of rheumatoid arthritis in Tikur Anbessa Specialized Hospital (TASH).

Methods

A cross-sectional study design was conducted on diagnosed patients with RA attending the rheumatology clinic at TASH from November 2018 to February 2019. Data was collected through patient interviews and chart reviews. The dataset was subjected to descriptive statistical analysis using the Statistical Package for Social Sciences (SPSS) version 25.

Results

A total of 1116 patients attended a rheumatologic clinic with rheumatologic complaints. The prevalence of rheumatoid arthritis was 18.5% (206/1116). Females were mostly affected (F:M 4.6:1). One hundred nineteen (57.8%) were between 35 and 64 years of age. The seropositivity for rheumatoid factor was 47.1%. Almost all patients had morning stiffness (89.8%) and joint pain (97.1%), with the majority (74.8%) having both small and large joint involvement. Nearly half of the patients, 99 (48.1%), had a joint deformity. Comorbid conditions seen in this study were hypertension (17%), overweight in 43 (20.9%), and obesity in 8 (3.9%). Methotrexate was the most prescribed agent (82.5%), both as monotherapy and along with other medications, but 139 (67.5%) of them were on prednisolone, which 2/3 (122) of patients took for 6 months in duration.

Conclusion

RA accounted for nearly one-fifth of the patients coming to the rheumatology clinics, with females affected more, which is similar to reports from some African countries. Disease-modifying anti-rheumatic drugs are the most prescribed agents, but most patients are on a prolonged dose of prednisolone.

Hypothyroidism risk associated with rheumatoid arthritis: A population-based retrospective cohort study

ABSTRACT

Studies on the thyroid disease risk in patients with rheumatoid arthritis (RA) associated with comorbidities are limited. This population-based retrospective cohort study investigated the hypothyroidism risk in patients with RA and the role of comorbidities.We used Taiwan National Health Insurance Research Database to identify 16,714 RA patients newly diagnosed in 2000 to 2008 and 66,856 control persons without RA, frequency matched by sex, age, and index year. Incidence and the RA group to controls hazard ratio of hypothyroidism were estimated.The hypothyroidism incidence was 1.74-fold higher in the RA group than in controls (16.6 vs 9.52 per 10,000 person-years), with the Cox method estimated adjusted hazard ratio of 1.67 (95% confidence interval = 1.39-2.00) after controlling for covariates. Near 75% of the study population were women, with the incidence 3.6-time higher than men in both groups. The hypothyroidism incidence increased with age, from 12.1 per 1000 person-years in 20 to 39 years to 20.0 per 1000 person-years in 60+ years in RA patients, higher than that in controls (7.17 vs 10.0 per 1000 person-years, respectively by age). Each comorbidity was related to an increased incidence and higher in the RA group than in controls. Among all comorbidities, stroke exerted the greatest impact in the RA group with an adjusted hazard ratio of 3.85 (95% confidence interval = 1.24-12.0).RA patients have an increased risk of developing hypothyroidism; this risk was pronounced in women and the elderly. RA patients should be closely monitored to prevent the development of hypothyroidism.

Association between rheumatoid arthritis and thyroid dysfunction: A meta-analysis and systematic review

OBJECTIVE

Rheumatoid arthritis (RA) is an autoimmune disorder. Multiple studies have investigated the risk of thyroid dysfunction in patients with RA but have reached conflicting conclusions. This systematic review aimed to determine whether patients with RA are at higher risk of thyroid dysfunction.

METHODS

We comprehensively reviewed online literature databases, including PubMed, Scopus, Embase, and the Cochrane Library, from their respective inception dates to March 25, 2022. Studies that provided data on at least one case of thyroid dysfunction in RA patients and their controls were included. Based on these data, we calculated pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) for thyroid dysfunction in RA and non-RA patients.

RESULTS

Twenty-nine studies met the inclusion criteria, involving a total of 35,708 patients with RA. The meta-analysis showed that, compared with non-RA patients, RA patients had an increased risk of developing thyroid dysfunction, particularly hypothyroidism (OR 2.25, 95% CI 1.78-2.84). Subgroup analysis suggested that study type and sample source of control group were the source of heterogeneity.

CONCLUSIONS

Patients with RA are at increased risk of developing thyroid dysfunction, especially hypothyroidism. Routine biochemical examination of thyroid function in RA patients should be strengthened. Larger prospective studies are needed to explore the causal relationship between RA and thyroid dysfunction, and to investigate the impact of thyroid dysfunction on RA disease activity, drug efficacy, and medication safety.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier CRD42022331142.

Clinical significance of monitoring hypothyroidism in patients with autoimmune rheumatic disease: a retrospective cohort study

We evaluated whether thyroid function test (TFT) screening is warranted for patients with autoimmune rheumatic diseases (ARD) by comparing the incidence of hypothyroidism requiring treatment (HRT) in ARD patients and healthy controls (HCs). Medical records of 2307 ARD patients and 78,251 HCs for whom thyroid-stimulating hormone (TSH) levels were measured between 2004 and 2018 were retrospectively reviewed. Cumulative incidence of HRT in ARD patients and HCs was compared. HRT development was evaluated with age- and sex-adjusted Kaplan–Meier curve. Risk factors were identified with Cox proportional hazard models. HRT was significantly more common in ARD patients than in HCs (6.3% vs. 1.9%, P < 0.001). After adjusting for age, sex, and baseline TSH level, hazard ratios for HRT were significantly higher in overall ARD patients (hazard ratio [95% confidence interval] 3.99 [3.27–4.87]; P < 0.001), particularly with rheumatoid arthritis and antinuclear antibody-associated diseases in female, and antinuclear antibody-associated diseases, spondyloarthritis, and vasculitis in male patients. Baseline high TSH level, thyroid-related autoantibody positivity, high IgG, and renal impairment were significant risk factors for hypothyroidism development in ARD patients; 20% of high-risk patients developed HRT during follow-up. HRT was significantly more frequent in ARD patients. Careful TFT screening and follow-up could help detecting clinically important hypothyroidism.

Coexistent subclinical hypothyroidism is associated with an increased risk of new cardiovascular events in rheumatoid arthritis: an explorative study

Objective: Autoimmune thyroid disease often coexists with rheumatoid arthritis (RA) and is associated with elevated cardiovascular (CV) risk. However, studies in RA patients are scarce. Our aim was to investigate whether autoimmune thyroid disease increases the risk of new cardiovascular disease (CVD) in RA.Method: Thyroid-stimulating hormone (TSH) and serum free thyroxine (FT4) were assessed in 323 RA patients participating in an ongoing prospective cohort study designed to assess CV risk factors, morbidity, and mortality. Cox proportional hazard models were used to calculate hazard ratios (HRs) for new CVD and adjusted for age, gender, smoking, prevalent CVD, thyroxine replacement therapy, and RA duration.Results: Of the 323 participants, 65.3% were female, and mean ± sd age was 63 ± 7 years. At baseline, 8.1% were hypothyroid (n = 26, 16 clinical, 10 subclinical), 6.8% hyperthyroid (n = 22, 13 clinical, 9 subclinical), and 85.1% (n = 275) euthyroid. A new CV event developed in 94 patients (29.1%) during follow-up. Compared to euthyroid patients, the HR adjusted for age, gender, and prevalent CVD was 2.83 [95% confidence interval (CI) 1.13-7.09; p = 0.026] for subclinical hypothyroidism. Further adjustment for smoking, thyroxine replacement therapy, and RA duration resulted in an HR of 3.0 (95% CI 1.19-7.54; p = 0.02) for CV events in patients with subclinical hypothyroidism.Conclusion: There was no difference in CVD between RA patients with hypothyroidism and hyperthyroidism versus euthyroid patients. Coexistence of subclinical hypothyroidism with RA is associated with a higher occurrence of new CV events. Treatment trials are needed to determine whether thyroxine supplementation can further improve CV outcome in these patients.

Autoimmune thyroid disorders and rheumatoid arthritis: A bidirectional interplay

Rheumatoid arthritis (RA) and autoimmune thyroid disease (AITD) can occur in the same patient in the autoimmune polyglandular syndrome 2. The association of the two conditions has been recognized long-time ago and the prevalence of AITD in patients with RA and vice versa is well assessed. Geographical variation of AITD and related autoantibodies in RA patients is partly due to ethnic and environmental differences of the studied populations. The impacts of thyroid disorders on RA outcome and vice versa are still controversy. In both AITD and RA genetic susceptibility and environmental factors play a synergic role in the development of the diseases. In this review we aimed at investigating the association of AITD and thyroid autoantibodies with RA, the common pathogenic pathways, the correlation with RA disease activity, and influence of the treatment.

Rheumatoid arthritis and thyroid dysfunction: A cross-sectional study and a review of the literature

Thyroid dysfunction appears to show increased prevalence in many autoimmune diseases; however, this comorbidity has not been properly investigated in patients with RA. This issue was addressed in this cross-sectional study. Using the database of the Clalit Health Services (CHS) in Israel, RA patients were paired with age- and sex-matched controls to compare the prevalence of hypothyroidism and hyperthyroidism. Chi-squared and t-tests were used for univariate analysis and a logistic regression model was used for multivariate analysis. The study included 11,782 patients with RA and 57,973 controls. The rate of thyroid dysfunction diseases in RA patients was increased compared with the prevalence in controls (16.0% and 11.7%, p < 0.001, for hypothyroidism; and 2.33% and 1.81%, p < 0.001 in hyperthyroidism, respectively). In a multivariate analysis, RA was associated with hypothyroidism (OR = 1.42, 95% CI 1.34-1.50) and hyperthyroidism (OR = 1.26, 95% CI 1.10-1.45). RA is associated with thyroid dysfunction. Therefore, physicians treating patients with RA should be aware of the possibility of comorbid thyroid dysfunction and treat accordingly.

Joint damage is amplified in rheumatoid arthritis patients with positive thyroid autoantibodies

BACKGROUND

Autoimmune thyroid disease (AITD), which is characterized by an increased presence of thyroid autoantibodies (TAbs), such as antibodies against thyroid peroxidase (TPOAbs) and antibodies against thyroglobulin (TgAbs), has been reported to be associated with rheumatoid arthritis (RA) because AITD and RA both involve autoimmunity. However, few data are available on the incidence of TAbs in Chinese RA patients, and studies on the association between TAbs and joint damage as well as synovitis in RA patients remain sparse. Here, we aimed to evaluate the incidence of TAbs in a consecutive Chinese RA cohort and to investigate whether the elevated presence of TAbs is associated with joint damage and synovitis in RA patients.

METHODS

A total of 125 hospitalized RA patients were consecutively recruited. Clinical data and available synovial tissues were collected at baseline, and TAbs and thyroid function were detected by chemiluminescent immunoassay. Patients who tested positive for TPOAbs or TgAbs were classified as the TAbs-positive group, and patients who tested positive for neither TPOAbs nor TgAbs were recruited as the TAbs-negative group. Disease activity was assessed using DAS28-ESR (the disease activity score in 28 joints and including the erythrocyte sedimentation rate). X-ray assessment of the hand/wrist was performed according to the Sharp/van der Heijde-modified Sharp score (mTSS), and patients with an mTSS score >10 were defined as having radiographic joint damage (RJD). Serial tissue sections were stained immunohistochemically for CD3, CD15, CD20, CD34, CD38, and CD68, and synovitis were assessed according to Krenn's synovitis score.

RESULTS

A total of 44 (35%) patients were positive for either TPOAbs or TgAbs. Importantly, there was a significantly greater percentage of patients with RJD in the TAbs-positive group versus the TAbs-negative group (68% vs. 42%, p = 0.005). Compared with the TAbs-negative group, significantly more CD38-positive plasma cells infiltrated the TAbs-positive synovium, and a higher percentage of patients with high-grade synovitis were observed in the TAbs-positive group (5/8, 63% vs. 5/14, 36%). Moreover, RF positivity and disease activity indicators, including TJC28, DAS28-ESR, and CDAI, were significantly higher in the TAbs-positive group (all p < 0.05). Adjusted logistic regression analysis revealed that positive TAbs (OR 2.999, 95% CI [1.301-6.913]; p = 0.010) and disease duration (OR 1.013, 95% CI [1.006-1.019]; p < 0.001) were independently associated with RJD, and an odds ratio of 2.845 (95% CI [1.062-7.622]) was found for RJD in women with positive TAbs (n = 37) compared with those without TAbs (n = 59) (p = 0.038).

CONCLUSION

Our data showed that joint destruction was amplified in RA patients with an elevated presence of TAbs, which supports the importance and necessity of TAbs and thyroid function screening and monitoring in RA patient management in clinical practice.

Coexistence of endocrinopathies in children with rheumatic diseases

Background and objectives

To examine the frequency of endocrinopathies in children with systemic lupus erythematosus (SLE) and juvenile idiopathic arthritis (JIA).

Design and setting

A cross-sectional study.

Patients and methods

A study was conducted in Saudi children with SLE and JIA who were seen at King Faisal Specialist Hospital and Research Centre, Riyadh, between September 2013 and April 2015. All enrolled patients completed the clinical evaluation, which included information about family history of autoimmune disease, growth parameters and tanner stage, as well as the following assessments: vitamin D profile (parathyroid hormone and 25-OH vitamin D levels), TSH, FT4 and total T3, thyroglobulin antibodies, thyroperoxidase antibodies, random blood sugar, Hb_A1C, IGF₁, IGF_BP-3, LH, and FSH.

Results

A total of 42 patients, 22 with JIA and 20 with SLE, were included in the study. The mean participant age was 12.2 ± 5.3 years with a mean disease duration of 3.2 ± 3.4 years. Female gender was predominant (17 SLE, 13 JIA) in the patient population. Fifteen patients (35.7%) presented with a family history of autoimmune disease. The most frequently detected endocrinopathies were vitamin D insufficiency (35%) and thyroid disease (31%). Eight JIA patients and 7 SLE patients exhibited low vitamin D levels; 10 patients presented with hyperparathyroidism. Thyroid dysfunction was observed in 13 patients (8 SLE, 5 JIA), and 2 patients were found to be euthyroid (normal TSH, FT4) with positive thyroid autoantibodies. Furthermore, 7 patients presented with subclinical hypothyroidism (high TSH, normal FT4), and 4 patients presented with overt hypothyroidism (high TSH, low FT4). Seven patients (4 SLE and 3 JIA) presented with short stature due to growth hormone insufficiency (low IGF₁, IGF_BP-3). Two patients exhibited delayed puberty accompanied by low LH levels. Diabetes mellitus was more frequently observed in patients with JIA (4 patients) than in patients with SLE (1 patient).

Conclusion

Our findings demonstrated that coexistence of endocrinopathies is not uncommon in children diagnosed with JIA and SLE. Abnormal thyroid function occurs frequently and at a similar rate in children diagnosed with SLE and JIA. Thus, screening for endocrinopathies, namely thyroid disease, during the assessment of childhood SLE and JIA is worth consideration.

Co-morbidity in patients with early rheumatoid arthritis - inflammation matters

Background

Patients with rheumatoid arthritis (RA) suffer from co-morbidities that contribute to a shortened lifespan. Inflammation is important for the development of cardiovascular disease, but little is known on its relationship with other co-morbidities. We investigated the role of inflammation for the development of new comorbidities in early RA.

Methods

Since 1995, all patients with early RA in Northern Sweden are included in a prospective study on co-morbidities, with a total of 950 patients being included. At the time for this study, 726 had been ill for ≥5 years. Data on co-morbidities, clinical and laboratory disease activity and pharmacological therapy were collected from patient records and further validated using a questionnaire at RA onset (T0) and after 5 years (T5).

Results

Of the patients, 53.2 % of the patients had one or more co-morbidity at onset, the commonest being: hypertension (27.3 %), obstructive pulmonary disease (13.9 %), diabetes (8.0 %), hypothyroidism (6.3 %) and malignancy (5.0 %). After 5 years, 41.0 % had developed at least one new co-morbidity, the most common being: hypertension (15.1 %), malignancy (7.6 %), stroke/transient ischemic accident (5.1 %), myocardial infarction (4.3 %) and osteoporosis (3.7 %). Age at disease onset, a raised erythrocyte sedimentation rate (ESR) at inclusion, previous treatment with glucocorticoids (GC; p < 0.001 for all), extra-articular RA (Ex-RA; p < 0.01), DAS28 (area under the curve) at 24 months (p < 0.05), previous smoking at inclusion (p = 0.058) and male gender (p < 0.01) were associated with a new co-morbidity overall at T5. Treatment with biologics (p < 0.05) reduced the risk. In multiple logistic regression modelling, ESR (p = 0.036) at inclusion was associated with a new co-morbidity after 5 years, adjusted for age, sex, smoking and GC treatment. In a similar model, Ex-RA (p < 0.05) was associated with a new co-morbidity at T5. In a third model, adjusted for age and sex, a new pulmonary co-morbidity was associated with a smoking history at inclusion (p < 0.01), but not with ESR.

Conclusion

There was substantial co-morbidity among early RA patients already at disease onset, with considerable new co-morbidity being added during the first five years. Measures of disease activity were associated with the occurrence of a new co-morbidity indicating that the inflammation is of importance in this context.

Prevalence of hypothyroidism in rheumatoid arthritis and its correlation with disease activity

OBJECTIVES

To analyse the prevalence of hypothyroidism in rheumatoid arthritis (RA) patients and to elucidate its correlation with disease activity.

METHODS

A total of 52 RA patients were enrolled in this study. All patients were assessed fully clinically and underwent routine laboratory investigation including thyroid function testing.

RESULTS

Hypothyroidism (defined as having a TSH level >4.20 μIU/mL) was observed in 20/52 (38.4%). Erythrocyte sedimentation rates (ESR) were found significantly elevated in patients with hypothyroidism compared to those without (36.3 ± 24.2 vs. 24.6 ± 9.0 mm/h). Disease activity parameters such as DAS-28-ESR, tender joint count; VAS scores were also significantly higher in the former. A significant correlation with serum TSH levels was observed with ESR and DAS-28-ESR.

CONCLUSION

Thyroid function test should be included in clinical evaluation of RA patients.

[Gender-specific differences in comorbidities of rheumatoid arthritis]

BACKGROUND

Comorbidities play an important role in the course and therapy of rheumatoid arthritis (RA). Sex-specific aspects are observed with regard to prevalence and manifestation of RA-related comorbidities.

AIM

A summary of current insights into sex and gender-related aspects of frequent comorbidities in RA is given.

MATERIAL AND METHODS

National data were analyzed and literature findings from meta-analyses, observational studies and reviews with regard to gender and RA-associated comorbidities are presented.

RESULTS

There are gender-specific differences in the prevalence of comorbidities of RA. Depression, fibromyalgia and hypothyroidism are more frequent in women than in men, whereas cardiovascular diseases and diabetes are more common in men. Osteoarthritis and osteoporosis are frequent in both sexes.

CONCLUSION

Sex and gender-specific aspects should be taken into consideration in the diagnostics and treatment of RA-related comorbidities.

Rheumatic and autoimmune thyroid disorders: a causal or casual relationship?

A number of dysfunctions may affect the thyroid gland leading either to hyper- or hypothyroidism which are mediated by autoimmune mechanisms. Thyroid abnormalities may represent an isolated alteration or they may be the harbinger of forthcoming disorders as is the case of well-characterized polyendocrine syndromes. Also, they may precede or follow the appearance of rheumatic manifestations in patients affected with connective tissue diseases or rheumatoid arthritis. The mechanisms by which autoimmune thyroid disorders may be linked to systemic autoimmune diseases have not been fully unraveled yet, however alterations of common pathways are suggested by shared genetic variants affecting autoantigen presentation and regulation of the immune response. On the other hand, the higher prevalence of autoimmune thyroid disorders over rheumatic diseases compels the chance of a mere causal concomitancy in the same patient. The aim of our paper is to provide an overview of available data on thyroid involvement in different rheumatic diseases and to go over the main rheumatic manifestations in the context of autoimmune thyroid diseases.

Cardiovascular involvement in autoimmune diseases

Autoimmune diseases (AD) represent a broad spectrum of chronic conditions that may afflict specific target organs or multiple systems with a significant burden on quality of life. These conditions have common mechanisms including genetic and epigenetics factors, gender disparity, environmental triggers, pathophysiological abnormalities, and certain subphenotypes. Atherosclerosis (AT) was once considered to be a degenerative disease that was an inevitable consequence of aging. However, research in the last three decades has shown that AT is not degenerative or inevitable. It is an autoimmune-inflammatory disease associated with infectious and inflammatory factors characterized by lipoprotein metabolism alteration that leads to immune system activation with the consequent proliferation of smooth muscle cells, narrowing arteries, and atheroma formation. Both humoral and cellular immune mechanisms have been proposed to participate in the onset and progression of AT. Several risk factors, known as classic risk factors, have been described. Interestingly, the excessive cardiovascular events observed in patients with ADs are not fully explained by these factors. Several novel risk factors contribute to the development of premature vascular damage. In this review, we discuss our current understanding of how traditional and nontraditional risk factors contribute to pathogenesis of CVD in AD.

Increased progression of carotid intima media thickness in thyroid peroxidase antibodies-positive rheumatoid arthritis patients

OBJECTIVE

Autoimmune diseases such as rheumatoid arthritis (RA) and hypothyroidism tend to cluster, and this coexistence amplifies the elevated cardiovascular risk in RA. Whether thyroid peroxidase antibodies (TPOabs) are associated with increased cardiovascular disease (CVD) risk has not been studied extensively. Therefore, this study determined firstly the prevalence of TPOabs in RA and secondly whether TPOabs were associated with CVD. Moreover, this study explored whether TPOabs were related to RA characteristics.

DESIGN AND METHODS

Data from the CARRÉ Study, an ongoing study investigating CVDs and its risk factors in RA (n=322), was used to ascertain the prevalence of TPOabs in RA patients. In addition, cardiovascular and RA disease characteristics were compared between TPOabs-positive and -negative patients at baseline and at a second visit after 3 years.

RESULTS

TPOabs were present in 47/322 (15%) RA patients and TSH levels were higher in TPOabs-positive patients (1.40 mU/l) compared with TPOabs-negative patients (1.26 mU/l, P=0.048). At baseline and after 3 years no association was observed between TPOabs and (risk factors for) CVD. Regression analyses revealed a significantly larger progression of carotid intima media thickness (cIMT; β=0.13 mm) in TPOabs-positive compared with TPOabs-negative patients independent of risk factors for cIMT progression. RA disease activity scores (DAS28) were higher in TPOabs-positive compared with TPOabs-negative patients (4.4 vs 3.8 P=0.018).

CONCLUSIONS

TPOabs were associated with increased cIMT progression. Moreover, an association between TPOabs and DAS28 was observed. Hence, TPOabs seems to have a role in the amplified cardiovascular risk in RA patients.

Thyroxin substitution and the risk of developing rheumatoid arthritis; results from the Swedish population-based EIRA study

OBJECTIVES

Hypothyroidism in iodine-repleted areas is usually of autoimmune nature and leads to chronic thyroxin substitution. It shares some risk factors with anti-citrullinated peptide antibodies (ACPA)-positive rheumatoid arthritis (RA). We asked whether thyroxin substitution associated with risk of ACPA-positive or ACPA-negative RA, and whether interactions with established risk factors were present.

METHODS

Data from a population-based case-control study with incident RA cases were analysed (1998 adult cases, 2252 controls). Individuals reporting thyroxin substitution were compared with those without thyroxin, by calculating OR with 95% CI, excluding participants reporting non-autoimmune causes for thyroxin substitution (thyroid cancer, iodine-containing drugs). Interaction was evaluated by attributable proportion (AP) with 95% CI.

RESULTS

Thyroxin substitution was associated with a twofold risk of both ACPA-positive (OR=1.9, 95% CI 1.4 to 2.6) and ACPA-negative RA (OR=2.1, 95% CI 1.5 to 3.1). For ACPA-positive RA, the risk associated with the combination thyroxin+ HLA-DRB1 shared epitope alleles (SE) was much higher (OR=11.8, 95% CI 6.9 to 20.0) than for thyroxin (OR=1.4, 95% CI 0.7 to 3.0) or SE (OR=5.7, 95% CI 4.6 to 6.9) alone, indicating a strong interaction (AP=0.5, 95% CI 0.2 to 0.8). Thyroxin substitution interacted non-significantly with smoking (AP=0.4, 95% CI 0.0 to 0.7; OR thyroxin+smoking=3.6, thyroxin only=1.5, smoking only=1.8). Thyroxin did not interact with the PTPN22*R620W allele.

CONCLUSIONS

Thyroxin users had a doubled risk of both ACPA-positive and ACPA-negative RA. The risk of ACPA-positive RA was manifold if they smoked or carried the SE. Furthermore, although joint symptoms can be a manifestation of hypothyroidism, physicians might consider whether it could be an early manifestation of RA.

Cardiovascular disease in autoimmune rheumatic diseases

Various autoimmune rheumatic diseases (ARDs), including rheumatoid arthritis, spondyloarthritis, vasculitis and systemic lupus erythematosus, are associated with premature atherosclerosis. However, premature atherosclerosis has not been uniformly observed in systemic sclerosis. Furthermore, although experimental models of atherosclerosis support the role of antiphospholipid antibodies in atherosclerosis, there is no clear evidence of premature atherosclerosis in antiphospholipid syndrome (APA). Ischemic events in APA are more likely to be caused by pro-thrombotic state than by enhanced atherosclerosis. Cardiovascular disease (CVD) in ARDs is caused by traditional and non-traditional risk factors. Besides other factors, inflammation and immunologic abnormalities, the quantity and quality of lipoproteins, hypertension, insulin resistance/hyperglycemia, obesity and underweight, presence of platelets bearing complement protein C4d, reduced number and function of endothelial progenitor cells, apoptosis of endothelial cells, epigenetic mechanisms, renal disease, periodontal disease, depression, hyperuricemia, hypothyroidism, sleep apnea and vitamin D deficiency may contribute to the premature CVD. Although most research has focused on systemic inflammation, vascular inflammation may play a crucial role in the premature CVD in ARDs. It may be involved in the development and destabilization of both atherosclerotic lesions and of aortic aneurysms (a known complication of ARDs). Inflammation in subintimal vascular and perivascular layers appears to frequently occur in CVD, with a higher frequency in ARD than in non-ARD patients. It is possible that this inflammation is caused by infections and/or autoimmunity, which might have consequences for treatment. Importantly, drugs targeting immunologic factors participating in the subintimal inflammation (e.g., T- and B-cells) might have a protective effect on CVD. Interestingly, vasa vasorum and cardiovascular adipose tissue may play an important role in atherogenesis. Inflammation and complement depositions in the vessel wall are likely to contribute to vascular stiffness. Based on biopsy findings, also inflammation in the myocardium and small vessels may contribute to premature CVD in ARDs (cardiac ischemia and heart failure). There is an enormous need for an improved CVD prevention in ARDs. Studies examining the effect of DMARDs/biologics on vascular inflammation and CV risk are warranted.

Autoimmune thyroid disease in rheumatoid arthritis: a global perspective

Objective. To determine the prevalence and impact of autoimmune thyroid disease (AITD) in patients with rheumatoid arthritis (RA). Methods. Eight-hundred patients were included. The association between AITD and RA was analyzed was analyzed by bivariate and multivariate analysis. In addition, a literature review was done focusing on geographical variations. Results. In our cohort the prevalence of AITD was 9.8% while the presence of antibodies was 37.8% for antithyroperoxidase enzyme (TPOAb) and 20.8% for antithyroglobulin protein (TgAb). The presence of type 2 diabetes, thrombosis, abnormal body mass index, and a high educational level was positively associated with AITD. The literature review disclosed a geographical variation of AITD in RA ranging from 0.5% to 27%. Autoantibody prevalence ranges from 6% to 31% for TgAb, 5% to 37% for TPOAb, and from 11.4% to 32% for the presence of either of the two. Conclusion. AITD is not uncommon in RA and should be systematically assessed since it is a risk factor for developing diabetes and cardiovascular disease. These results may help to further study the common mechanisms of autoimmune diseases, to improve patients' outcome, and to define public health policies. An international consensus to accurately diagnose AITD is warranted.