Occurrence of Hashimoto's thyroiditis and diabetes mellitus in patients with rheumatoid arthritis

Association Between Hashimoto's Thyroiditis and Rheumatoid Arthritis: A Bidirectional Mendelian Randomization Study

Background: We aim to investigate the possible causal association between Hashimoto's thyroiditis (HT) and rheumatoid arthritis (RA) using Mendelian randomization (MR) methods. Methods: A bidirectional MR analysis was conducted to evaluate the causal association between HT and RA. We obtained summary statistics data from two extensive genome-wide association studies (GWAS) comprising 15,654 cases of HT and 14,361 cases of RA. The primary effect estimate utilized in this study was the inverse-variance weighted (IVW) method. To ensure the reliability and stability of the results, we employed several additional methods for testing, including MR-Egger, weighted median, simple mode, weighted mode, and MR-PRESSO. Results: Our study revealed compelling evidence of bidirectional causality between HT and RA. When HT was considered as an exposure factor and RA was considered as an outcome factor, this study revealed a positive correlation between HT and RA (IVW: odds ratio [OR] = 2.4546, 95% confidence interval [CI], 1.1473-5.2512; p = 0.0207). Conversely, when we examined RA as the exposure factor and HT as the outcome factor, we still found a positive correlation between them (IVW: OR = 1.2113, 95% CI, 1.1248-1.3044; p = 3.9478 × 10-7). Conclusions: According to our research findings, there exists a bidirectional positive causal relationship between HT and RA among European populations. This implies that individuals with HT have an elevated risk of developing RA, and conversely, individuals with RA have an increased risk of developing HT.

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.

The Rochester Epidemiology Project: exploiting the capabilities for population-based research in rheumatic diseases

The Rochester Epidemiology Project (REP) is a patient record-based database based upon a medical records-linkage system for all residents of the Olmsted County, MN, USA. This comprehensive system includes all health-care providers of patients resident in this geographically defined region. It uniquely enables long-term population-based studies of all medical conditions occurring in this population; their incidence and prevalence; permits examination of disease risk and protective factors, health resource utilization and cost as well as translational studies in rheumatic diseases.

Autoimmune diseases co-occurring within individuals and within families: a systematic review

BACKGROUND

Autoimmune diseases have been observed to coexist both within individuals and within families. It is unclear whether clinical reports of comorbid autoimmune diseases represent chance findings or true associations. This systematic review evaluates the current level of evidence on the coexistence of selected autoimmune diseases within individuals and families. We reviewed the associations among 4 TH1-associated autoimmune diseases: insulin-dependent diabetes mellitus, autoimmune (Hashimoto) thyroiditis, rheumatoid arthritis, and multiple sclerosis.

METHODS

Studies quantifying the coexistence between the selected diseases, published through March 2004, were identified from Medline and Embase searches. Study eligibility was determined on the basis of preestablished criteria, and relevant data were extracted according to a fixed protocol. We determined the prevalence of comorbid autoimmune disease according to index disease and then compiled summary statistics. Heterogeneity among studies was assessed by exact likelihood ratio tests and Monte Carlo inference.

RESULTS

We found 54 studies that met the eligibility criteria. Of these, 52 studies examined the coexistence of disease within individuals and 9 studies examined within-family associations. The majority of studies were uncontrolled and did not account for confounding factors. There was substantial evidence for heterogeneity among studies. Although inconclusive, the data appear to support an increased prevalence of autoimmune thyroiditis among patients with rheumatoid arthritis and those with insulin-dependent diabetes mellitus, and an inverse association between rheumatoid arthritis and multiple sclerosis.

CONCLUSION

Although the available evidence does not permit firm conclusions regarding comorbidities among the selected autoimmune diseases, results are sufficiently suggestive to warrant further study.

Insulin-dependent diabetes mellitus associated with autoimmune thyroiditis and rheumatoid arthritis

A case associated with insulin-dependent diabetes mellitus (IDDM), rheumatoid arthritis (RA), and autoimmune thyroid disease (AITD) was reported. A high titer of anti-glutamic acid decarboxylase antibody (GAD) and a positive islet cell antigen were observed. The patient's human leukocyte antibody (HLA) haplotype was a homozygote of DQA1*0301, DQB1*0401, and DRB1*0405. Because this haplotype was in linkage disequilibrium with DPB1*0501, an allele associated with AITD in Japanese patients, the patient was homozygous for alleles susceptible to IDDM, RA, and AITD. A specific HLA haplotype susceptible to several autoimmune disease may result in the development of IDDM, RA, and AITD.

Spontaneous adult-onset hypothyroidism in a cat

Spontaneous adult-onset hypothyroidism, confirmed by a thyroid-stimulating hormone stimulation test, thyroid biopsy, and response to replacement therapy, is described in a female cat. Clinical signs consisted of profound apathy, hypothermia, poor hair growth, severe seborrhea sicca, and a puffy face. Cutaneous histological changes consisted of epidermal and follicular hyperkeratosis, teloginization of hairs, and dermal mucin deposition. There was no adnexal atrophy. Lymphocytic thyroiditis, equivalent to Hashimoto's thyroiditis, was shown by thyroid biopsy. Clinical signs rapidly responded to thyroxine replacement therapy. Glucose intolerance was coexistent with the hypothyroidism, but was not dramatically influenced by thyroxine therapy and probably was an independently occurring endocrinopathy.

Thyroid dysfunction in rheumatoid arthritis: a controlled prospective survey

OBJECTIVES

To determine whether thyroid dysfunction is found with increased frequency in patients with rheumatoid arthritis (RA).

METHODS

A controlled prospective survey was conducted on a cohort of patients with RA derived from a hospital clinic and a private surburban rheumatology practice. A control group with similar demographic features was generated from the same sources and included subjects with either osteoarthritis or fibromyalgia. Consecutive patients were evaluated over a six month period. The evaluation included a complete history and physical examination, and determination of serum thyroxine, free thyroxine, triiodothyronine, thyroid stimulating hormone (IRMA), antinuclear antibodies, and rheumatoid factor.

RESULTS

Of the 91 women with RA evaluated, 29 (30%) had evidence of thyroid dysfunction compared with 10 (11%) of 93 controls. The excess thyroid dysfunction is due to either hypothyroidism or Hashimoto's thyroiditis and was independent of age, increasing duration of disease, rheumatoid factor, and antinuclear antibodies.

CONCLUSIONS

Thyroid dysfunction is seen at least three times more often in women with RA than in women with similar demographic features with non-inflammatory rheumatic diseases such as osteoarthritis and fibromyalgia.

Hashimoto's thyroiditis with granulomas: A unifying immunological etiology?

Two cases of granulomatous inflammation of the thyroid gland associated with Hashimoto's thyroiditis are presented. In neither case is there an obvious cause of granuloma formation, the only accompanying abnormality being rheumatoid arthritis in one of the patients. Autoimmune thyroid disease has been reported in association with sarcoidosis as well as rheumatoid arthritis, diseases in which cellular immunity is activated. Immune mechanisms alone are capable of initiating and amplifying granulomatous inflammation. In this report, we suggest that the granulomas in both cases may have their origin in immunological malfunction, the same immunological malfunction responsible for Hashimoto's thyroiditis.

Thyroid dysfunction in a prospectively followed series of patients with progressive systemic sclerosis

Thirty-nine patients with progressive systemic sclerosis (PSS) in stable clinical conditions were extensively evaluated for the presence of thyroid disease. Two patients had previously undetected hypothyroidism while 7 additional patients had normal serum thyroid hormone levels but an exaggerated TSH response to thyrotropin-releasing hormone (TRH) administration, consistent with subclinical hypothyroidism. Four of the 9 subjects with abnormal TRH responses had positive antithyroid antibodies and of the remaining 5, 4 had been on chlorambucil or prednisone. Basal TSH and TSH response to TRH were significantly higher in PSS patients as a group when compared to a control group and increased with increasing duration of PSS. Serum antithyroid antibodies (antithyroglobulin and/or antimicrosomal antibodies) were positive in 18% and thyroid scans were abnormal in 18% of the patients. The euthyroid sick syndrome was not seen. Our findings indicate an increased frequency of, sometimes previously unsuspected, clinical and subclinical hypothyroidism in stable PSS patients which appears to be autoimmune in nature and becomes more prevalent with increased PSS duration. Careful and regular monitoring of the thyroid function in PSS patients is advisable.

The endocrinologic associations of the autoimmune rheumatic diseases

Having seen five patients with both SLE and thyroid disease (case reports available on request) in a short period of time, we have undertaken a survey of the association between the ARD and endocrine disorders. On the basis of a literature review and our own reported study, it is apparent that an association between these major groups of disorders is well established with some individual diseases, though much more dubious in others (Table 3). The possibility of coexistent endocrine disease in a patient with a multisystem ARD should be carefully considered throughout the course of the patient's follow-up.

Organ-specific autoantibodies in non-organ-specific autoimmune diseases with special reference to rheumatoid arthritis

Sera from 367 patients with rheumatoid arthritis (RA) and from 102 patients with other non-organ-specific (NOS) autoimmune diseases were examined for the presence of organ-specific (OS) autoantibodies. The incidence of these OS autoantibodies was not increased in patients with NOS autoimmune diseases with the exception of thyroglobulin antibodies, which were significantly more frequent in RA (P less than 0.001) and in Sjögren's syndrome (P less than 0.05) patients than in normal controls. Investigation of 169 patients with OS autoimmune diseases did not reveal an increased prevalence of NOS autoantibodies. In RA patients, OS autoantibodies correlated with NOS autoantibodies (P less than 0.04) and with HLA-DR3 antigen (P less than 0.01).

Hashimoto's thyroiditis and polyarthritis: a possible subset of seronegative polyarthritis

Fifteen patients presenting with inflammatory polyarthritis who had Hashimoto's thyroiditis were investigated. Only 2/15 had frank myxoedema, 8/15 had incipient hypothyroidism (raised levels of thyrotropin or early symptoms of mild hypothyroidism), and 5/15 were euthyroid (thyrotropin levels normal). The presence or absence of rheumatoid factor (RF) distinguished two subgroups with different severity of synovitis. Nine out of 15 (group A) who remained RF negative throughout their follow-up had mild polyarthritis, lacked nodules or erosions on x-ray, and required, in addition to thyroid replacement, non-steroidal anti-inflammatory drugs for control of synovitis. Six out of 15 who remained RF positive (group B) had more severe synovitis, nodules, and erosive x-ray changes, and some required remittive drug treatment to control their disease. HLA-DR2 was present in 67% of group A and 13% of group B patients, while HLA-DR4 was present in 67% of group B and 33% of group A. Group A patients may represent a subset of patients with Hashimoto's thyroiditis and seronegative inflammatory polyarthritis, while group B patients appear to have features suggesting the coexistence of both rheumatoid arthritis and Hashimoto's thyroiditis.

Skeletal and joint manifestations of childhood diabetes

The rheumatologic and skeletal manifestations of childhood diabetes have only recently been appreciated. This article reviews bone loss (osteopenia) in this population, and the differential diagnosis of the limited joint mobility commonly found in insulin-dependent diabetes in childhood.

Evidence for an association between rheumatoid arthritis and autoimmune endocrine disease

Evidence is presented for the first time of a significantly increased prevalence of type 1 (insulin-dependent) diabetes in the close relatives of patients with rheumatoid arthritis. Thirty-nine (13%) of 295 patients with classical or definite rheumatoid arthritis had a first or second degree relative with type 1 diabetes and 38 (13%) had a close relative with autoimmune thyroid disease. These findings could be compatible with a possible common genetically determined mechanism of susceptibility to both diseases.