Subclinical hypothyroidism is associated with higher carotid intima-media thickness in cross-sectional analysis of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Relationship of thyroid function with intracranial arterial stenosis and carotid atheromatous plaques in ischemic stroke patients with euthyroidism

“…Our results are consistent with previous studies showing associations between low fT4 levels and elevated levels of inflammatory markers [17], mitral annular calcification [24], and thickening of the carotid intima media [18–21] in stroke patients with euthyroidism. Since our findings were obtained with a relatively large and inclusive sample of ischemic stroke patients, we strengthen the case for targeted screening of ischemic stroke patients with low-normal thyroid function for carotid atheromatous plaques.…”

“…In addition, thyroid function at the low end of the normal range (still within euthyroid limits) has been associated with increased levels of inflammatory markers [17], thickening of the carotid intima media [18–21], stenosis of the internal carotid artery [22], and ulceration of carotid artery plaques [23]. These associations suggest that thyroid function may be associated with intracranial arterial stenosis and/or carotid atheromatous plaques in ischemic stroke patients, even in patients with euthyroidism.…”

Thyrotrophin levels and coronary artery calcification: Cross‐sectional results of the Brazilian Longitudinal Study of Adult Health (ELSA‐Brasil)

“…FT4 levels were measured in participants exhibiting altered TSH levels. In this study, reference range levels were 0.4‐4.0 mIU/L for TSH and 10.3‐24.45 pmol/L for FT4, similar to other ELSA‐Brasil studies . ELSA‐Brasil participants were classified into five categories of thyroid function, according to TSH and FT4 levels and information related to the use of medication to treat thyroid disorders: clinical hyperthyroidism (low serum TSH and high FT4 levels or use of medication to treat hyperthyroidism), subclinical hyperthyroidism (low serum TSH, normal FT4 levels and no use of drugs to treat thyroid diseases), euthyroidism (normal TSH and no use of thyroid drugs), subclinical hypothyroidism (high TSH levels, normal FT4 levels and no use of drugs to treat thyroid diseases) and clinical hypothyroidism (high TSH and low FT4 levels, or use of levothyroxine to treat hypothyroidism).…”

“…Our results remained positive after multivariate adjustment for sociodemographic and cardiovascular risk factors. Evidence of the association between subclinical thyroid disorders and other measures of subclinical atherosclerosis such as the intima‐media thickness is also heterogeneous, with an association with SCHyper, SCHypo or no association . Previous published data of ELSA‐Brasil reported an association of high IMT values in SCHypo .…”

“…Main logistic regression models were built using the CAC score as the dependent variable and TSH quintile groups as the main independent variable. Models are presented crude, adjusted for age (continuous), sex and race/skin colour (Model 1), with further adjustment for hypertension, diabetes mellitus, dyslipidaemia, smoking status, BMI, HDL‐cholesterol, triglycerides, glomerular filtration rate and log‐transformed high‐sensitivity C‐reactive protein (Model 2) and further adjustment for insulin resistance (Model 3), because in previous analyses of thyroid function with carotid intima‐media thickness (CIMT), insulin resistance was an important confounder . In these main models, the 3rd TSH quintile group was defined as the reference category, to evaluate nonlinear (U‐shaped) associations.…”