Metabolic Syndrome, Thyroid Function and Autoimmunity - The PORMETS Study

Abstract

Background The prevalence of thyroid dysfunction and autoimmunity in the Portuguese population has not yet been estimated. However, the national prevalence of the metabolic syndrome remains high. The association of thyroid pathology with cardiovascular risk has been addressed but is still unclear. Our study aimed to evaluate the prevalence of thyroid dysfunction and autoimmunity and to assess the associations of thyroid-stimulating hormone and thyroid hormones and antibodies with metabolic syndrome, its components, and other possible determinants in a national sample. Material and methods The present study included a subsample of 486 randomly selected participants from a nationwide cross-sectional study sample of 4095 adults. A structured questionnaire was administered on past medical history and socio-demographic and behavioural characteristics. Blood pressure (BP) and anthropometric measurements were collected, and the serum lipid profile, glucose, insulin, hs-CRP, TSH, FT4, FT3 and thyroid antibodies were measured. Results In our sample, the prevalence of hypothyroidism, hyperthyroidism and undiagnosed dysfunction was 4.9%, 2.5% and 72.2%, respectively. Overall, the prevalence of positivity for the thyroid peroxidase and thyroglobulin antibodies was 11.9% and 15.1%, respectively. A positive association was found between free triiodothyronine and metabolic syndrome (OR: 2.019; 95% CI: 1.196, 3.410). Additionally, thyroid peroxidase antibodies had a negative association with metabolic syndrome (OR: 0.465; 95% CI: 0.236, 0.917) and its triglyceride component (OR: 0.321; 95% CI: 0.124, 0.836). Conclusion The prevalence of undiagnosed thyroid dysfunction and autoimmunity was high. Thyroid peroxidase antibodies were negatively associated with metabolic syndrome and its triglyceride component, whereas the free triiodothyronine level was positively associated with metabolic syndrome.

Subclinical hypothyroidism and anxiety may contribute to metabolic syndrome in Sichuan of China: a hospital-based population study

“…In the present study, it was proved that fT4 was associated with components of MetS, which was validated in NHNES database and consistent with previous studies 21,22 . Therefore, the thyroid function screening should be also paid attention in MetS subjects.…”

The Role of Thyroid Hormones and Autoantibodies in Metabolic Dysfunction Associated Fatty Liver Disease: TgAb May Be a Potential Protective Factor

“…Another study on Portuguese population discovered a negative association of TPOAb positivity with MetS and its TG component. In contrast, no association of TgAb was not found with MetS or its components (20). Therefore, not only is there a lack of consistent findings in the relationship between thyroid autoantibody positivity and the prevalence of MAFLD, but also a lack of understanding of the respective roles of TPOAb and TgAb, which requires further study.…”

“…Recently, studies have shown that the presence of thyroid antibodies are involved in glucose and lipid metabolic disorders ( 17 , 18 ). In addition, thyroid autoimmune may have a tumor-promoting role in breast cancer carcinogenesis ( 19 ) and may act as an independent CVD risk factor by promoting chronic inflammation ( 20 ). The relationship between thyroid antibodies and MAFLD remains unclear and few previous studies have been done.…”

The role of thyroid hormone in metabolism and metabolic syndrome

“…Serum FT3 or total T3 were also evaluated in some studies. 15,16,22,27,33,35–38,45–47,49,54,57,60,73,74,77–79,81,82,85,86,89,93,96,101,105–110…”