A random sample from Wales. IV. Circulating gastric and thyroid antibodies and antinuclear factor

A Scoping Review on the Prevalence of Hashimoto's Thyroiditis and the Possible Associated Factors

BACKGROUND

Hashimoto's thyroiditis (HT) is the most common autoimmune thyroid disease (AITD) and is characterized by the presence of thyroid autoantibodies against thyroid peroxidase and/or thyroglobulin. Several studies have found that the global prevalence of HT has increased in recent decades, while others show the opposite.

METHODS AND RESULTS

The objective of this scoping review was to synthesize and analyze the different studies that have evaluated the prevalence of HT (in adults) and the possible associated factors. The following databases were consulted, as follows: MEDLINE, Web of Science, PubMed, and Scopus. The search terms "epidemiology", "prevalence", and "Hashimoto disease" and "Hashimoto thyroiditis" were used. The search was limited to articles published between January 1965 and October 2024, and only articles in English were considered. In order to reduce selection bias, each article was scrutinized using the JBI Critical Appraisal Checklist independently by two authors. Studies were included if the number of participants (study population and/or cases and controls, depending on the study design) was clearly described and duplicate studies were excluded. A total of 59 studies were identified, the vast majority of them used a cross-sectional design, using different methods of disease assessment.

CONCLUSIONS

Globally, the prevalence of HT is estimated to be between 5-10%; some areas with prevalences > 20% and others < 0.5% were identified. Prevalence is also higher in women than in men. Multiple underlying factors (genetic, epigenetic, environmental, and lifestyle), together with socioeconomic, nutritional, overdiagnosis, inter alia, may explain (at least in part) the wide variability in the prevalence of HT.

Global prevalence and epidemiological trends of Hashimoto's thyroiditis in adults: A systematic review and meta-analysis

Objective

Although Hashimoto's thyroiditis is associated with cardiovascular disease and malignancy, the global status of Hashimoto's thyroiditis is not well characterized across regions. Our objective was to evaluate the prevalence and trends of Hashimoto's thyroiditis in adults in regions with different economic income levels around the world.

Methods

For this systematic review and meta-analysis, we searched PubMed, Embase, MEDLINE, Scopus, and Web of Science databases, and 48 random-effects representative studies from the inception to June 2022 were included without language restrictions to obtain the overall prevalence of Hashimoto's thyroiditis in adults worldwide. In addition, we stratified by time of publication, geographic region, economic level of the region of residence, gender, diagnostic method, etc.

Results

A total of 11,399 studies were retrieved, of which 48 met the research criteria: 20 from Europe, 16 from Asia, five from South America, three from North America, and three from Africa. Furthermore, there are two projects involving 19 countries and 22,680,155 participants. The prevalence of Hashimoto's thyroiditis was 7.5 (95%CI 5.7-9.6%), while in the low-middle-income group the prevalence was 11.4 (95%CI 2.5-25.2%). Similarly, the prevalence was 5.6 (95%Cl 3.9-7.4%) in the upper-middle-income group, and in the high-income group, the prevalence was 8.4 (95%Cl 5.6-11.8). The prevalence of Hashimoto's varied by geographic region: Africa (14.2 [95% CI 2.5-32.9%]), Oceania (11.0% [95% CI 7.8-14.7%]), South America and Europe 8.0, 7.8% (95% Cl 0.0-29.5%) in North America, and 5.8 (95% Cl 2.8-9.9%) in Asia. Although our investigator heterogeneity was high (I²), our results using a sensitivity analysis showed robustness and reliability of the findings. People living in low-middle-income areas are more likely to develop Hashimoto's thyroiditis, while the group in high-income areas are more likely to develop Hashimoto's thyroiditis than people in upper-middle-income areas, and women's risk is about four times higher than men's.

Conclusions

Global Hashimoto's thyroiditis patients are about four times as many as males, and there are discrepancies in the regions with different economic levels. In low-middle-income areas with a higher prevalence of Hashimoto's thyroiditis, especially countries in Africa, therefore local health departments should take strategic measures to prevent, detect, and treat Hashimoto's thyroiditis. At the same time, the hidden medical burden other diseases caused by Hashimoto's thyroiditis should also be done well.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD 42022339839.

The incidence and prevalence of thyroid autoimmunity

The thyroid gland is the most common organ affected by autoimmune disease. Other autoimmune diseases, most notably type 1 diabetes mellitus, are increasing in incidence. It is unknown whether autoimmune thyroid diseases are following the same pattern. This review summarizes studies of autoimmune thyroid disease incidence and prevalence since 1950, not only for these measures of occurrences, but also for commenting on identified risk factors for thyroid autoimmunity. We find that incidence of autoimmune thyroid disease is currently higher than in historic series although the studies are so variable in design, patient population, disease definition, and laboratory methods that it is impossible to tell whether this difference is real. Further research is required to assess the possibility of changing disease patterns of autoimmune thyroid disease as opposed to simple changes in diagnostic thresholds.

Autoantibodies, mortality and ageing

Immunological failure may be the cause of predisposition to certain infections, neoplasms, and vascular diseases in adulthood. Mortality risks through life may reflect an undetermined number of causes. This study describes the prevalence of positivity of autoantibodies through life, along with general and specific mortality causes in three countries with different socioeconomic development (Guatemala, Mexico and the United States). Prevalence of autoantibodies by age was obtained from previous reports. In spite of having involved different ethnic groups, the observed trends in prevalence of autoantibodies, as well as mortality through life, showed a similar behavior. Thus, both the increase in autoantibody production and death risk as age rises, may share physiopathological phenomena related to the ageing process.

Vascular disease risk factors, urinary free cortisol, and health histories in older adults: shyness and gender interactions

We studied relationships between shyness and health during a health screening survey of older adults (ages 50-88) living in an active retirement community in the southwestern United States (n = 232). As in previous studies of infants, older individuals with hay fever, insomnia and constipation were more shy than those without these problems. Shy persons overall showed higher sitting systolic blood pressure and a larger fall in orthostatic systolic blood pressure on standing; shy men had a greater prevalence of hypertension histories than did low-shy men. Shy subjects of both sexes had lower HDL cholesterol and higher triglycerides than did low-shy subjects; shy women tended to have higher LDL cholesterol than did low-shy women. In contrast with findings of elevated salivary cortisol in extremely inhibited children of both sexes, only shy women had higher 24 h urinary free cortisol excretion than did low-shy women; men showed the opposite pattern, possibly related to suppression of aggression. Shy men also tended to report a higher prevalence of thyroid disease history than did low-shy men (20% versus 6%). Notably, autoimmune thyroiditis has previously been linked with panic and depression, disorders which in turn have been associated with shyness. Taken together with previous work in shy children and their families, the data raise the possibility of (a) increased risk for arteriosclerotic vascular disease; and (b) increased risk of adrenal- and/or thyroid-related diseases in certain shy older adults.

Type 1 diabetes and latent pernicious anaemia

OBJECTIVE

To determine the prevalence of latent pernicious anaemia (PA) in Type 1 diabetics.

DESIGN

Patients with Type 1 diabetes were screened at two yearly intervals on a continuing basis.

SETTING

Diabetic Unit, Royal Perth Hospital, Western Australia.

PATIENTS

Three hundred and seventy-one patients, 156 females and 215 males, attending a diabetic clinic. They were classified as having Type 1 diabetes on the basis of age of onset less than 40 years and requiring insulin from the start.

MAIN OUTCOME MEASURES

Serum cobalamin levels were measured and studies of thyroid function and a blood count were done. Patients with a reduced serum level of cobalamin had tests for cobalamin absorption.

RESULTS

Six patients had a low serum cobalamin level; five showed malabsorption of the vitamin which could be corrected by the addition of intrinsic factor. Four of these patients had no clinical signs of PA. The fifth was mildly anaemic (haemoglobin level 111 g/L) and had megaloblastic bone marrow. He was classified as having frank PA. The sixth patient was not available for further testing. These results give a prevalence of latent PA of 11 per 1000 in Type 1 diabetics, compared with 3.9 per 1000 in diabetics with clinically manifest disease and 1.27 per 1000 in the general population. All four patients with latent PA had hypothyroidism, based on low thyroxine levels, increased levels of thyroid stimulating hormone and the presence of thyroid antibodies.

CONCLUSION

Latent PA is not uncommon in Type 1 diabetics. It has a long preclinical course and occurs in those patients with thyroid disease. The screening of Type 1 diabetics for latent PA has worthwhile benefits as a "preventive" health measure.

Autoimmune reactions to gastric mucosa in chronic gastritis: a review

The main results of two-decade co-operation between Tartu University, Estonia, and the University of Helsinki, Oulu and Tampere in Finland on immunology of chronic gastritis are presented. These results include data on cell-mediated and humoral immunity to autoantigens from gastric antrum and corpus mucosa in chronic gastritis, gastric ulcer, gastric carcinoma and other gastric diseases, as well as in random samples from two populations.

Rheumatic heart disease and thyroid status

A retrospective analysis of 76 patients with rheumatic heart disease revealed nine with thyrotoxicosis, three with hypothyroidism and seven with normal thyroid function and circulating thyroid antibodies. This suggests that there may be an association between rheumatic heart disease and thyroid dysfunction. The findings emphasize the need to formally exclude hyperthyroidism in patients with atrial fibrillation whatever the apparent cause. They also imply a possible autoimmune factor in the pathogenesis of rheumatic heart disease and suggest that patients with rheumatic heart disease may develop clinical or sub-clinical thyroid disease.

Antinuclear antibodies (ANA): immunologic and clinical significance

The methods currently used for the detection of ANA have been analyzed, with emphasis on their practical application to the diagnosis of the CTD. The use of the indirect IF-ANA test was recommended as a screening procedure to detect ANA. The need to standardize the technique using a single substrate and fluorescent conjugates with uniform F/P ratios was stressed. Most importantly, the value of titrating ANA for the diagnosis of the CTD was discussed. ANA titers higher than 1/500 are usually very significant clinically, often found in spontaneous or drug-induced SLE and few other CTD. The immunologic aspects of ANA and their potential value as aids in the diagnosis and management of the CTD were discussed. Anti-nDNA antibodies have been found to have a high degree of specificity for SLE and high titers of these antibodies correlate well with low levels of serum complement and severity of kidney involvement. The spectrum of ANA in the sera from patients with SLE has been expanded with the finding of anti-Sm antibodies which, when detected by gel precipitation with prototype serum, have been found so far only in SLE. Some of these antibodies have been found to have prognostic significance. Patients with MCTD and a group of patients with SLE have high titers of serum ANA with specificity for an RNase-sensitive component of ENA. The group of SLE patients defined by the presence of these antibodies (anti-Mo) have a better prognosis and in general develop only mild nephritis or have no kidney involvement at all. High titers of pure antinucleolar antibodies probably are found almost exclusively in the sera of patients with scleroderma. Some ANA have organ specificity, and GS-ANA have been found in all patients with Felty's syndrome and in a large proportion of patients with RA. One of the great advances in the field has been the recognition that ANA can be induced in the human and in experimental animals by the use of a number of therapeutic agents. Some of these agents can also induce a clinical picture resembling spontaneous SLE, though kidney involvement does not occur or is extremely mild. It is interesting that the whole spectrum of ANA can be found in drug-induced LE except anti-nDNA antibodies which have been associated to the pathogenesis of immune complex nephritis in spontaneous SLE. There is no doubt that research on ANA has contributed a great deal to the understanding of the CTD and will continue to be a valuable tool for the clinician and the investigator.

Liver abnormalities and gallstones: a prospective combined clinical, histological and surgical study

In a prospective study of 57 patients coming to elective cholecystectomy for gallstone disease, clinical, biochemical and immunological features have been correlated with the histological changes in core biopsies of the liver obtained at surgery. Only 13 liver biopsies were normal. Ten biopsies showed changes of acute duct obstruction, 16 showed minimal portal tract abnormalities and 10 showed moderate portal tract inflammation and scarring. Histological changes were more marked in male patients. Clinical and biochemical investigations were not useful in predicting histological appearance, apart from cases with jaundice at the time of operation where changes of acute duct obstruction were usually, but not invariably, seen. Atuo-antibodies were present in 50 per cent of cases tested and all persisted for at least 6 months after operation. They were commoner in patients with more marked histological changes. Operative cholangiography was of little use in predicting histological change. These findings suggest that the possibility of gallstones should be considered in the interpretation of any abnormal liver biopsy irrespective of clinical symptoms or biochemical investigations.