Characteristics of coronary artery disease in patients with subclinical hypothyroidism: evaluation using coronary artery computed tomography angiography

Associations Between Hypothyroidism and Subclinical Atherosclerosis Among Male and Female Patients Without Clinical Disease Referred to Computed Tomography

OBJECTIVES

Hypothyroidism is recognized as a risk factor for coronary artery disease (CAD). However, reports are conflicting when the results are stratified by sex and the underlying risk of CAD. We examine the sex-specific associations of hypothyroidism with coronary calcification and plaques.

METHODS

Retrospective cross-sectional study was conducted among adult patients referred to (64 multidetector spiral) computed tomography. Those with pre-existing CAD were excluded. Hypothyroidism was defined as thyroid-stimulating hormone ≥ 4.5 mU/L. Plaques were determined based on quantification of coronary calcium and coronary computed tomography angiography.

RESULTS

A total of 2499 patients (1544 male and 955 female) were included. The prevalence of hypothyroidism was significantly higher in female than in male patients (18.0% vs 12.9%, P < .001), in all patients and those <65 years. Hypothyroidism in male patients was significantly associated with higher coronary calcium score > 0, higher coronary calcium score groups, and both soft and calcified plaques (P = .027, P = .032, P = .005, and P = .017, respectively). After adjusting for traditional coronary risk factors, the higher risk in male patients remained significant for coronary plaque but not for coronary calcium score >0 (odds ratios and CIs were 1.77, 1.08-2.90, P = .023 and .98, 0.63-1.52, P = .925, respectively). On the other hand, hypothyroidism in female patients was not significantly associated with coronary calcification nor plaques in both univariate and multivariate analyses.

CONCLUSIONS

There are sex-specific differences in the association of hypothyroidism with subclinical atherosclerosis. The higher risk of coronary plaques but not calcification in male patients was independent of traditional coronary risk factors. The lack of associations in female patients may be related to lower underlying risk of CAD.

Thyroid disorders and cardiovascular manifestations: an update

Cardiovascular disease (CVD) remains the leading cause of death worldwide, representing a major health, social, and economic issue. Thyroid disorders are very common and affect >10% of the adult population in total. The aim of this review is to describe the physiologic role of thyroid hormones on cardiovascular system, to present cardiovascular manifestations in patients with thyroid disorders, emphasizing in molecular mechanisms and biochemical pathways, and to summarize current knowledge of treatment options. Thyroid hormone receptors are located both in myocardium and vessels, and changes in their concentrations affect cardiovascular function. Hyperthyroidism or hypothyroidism, both clinical and subclinical, without the indicated therapeutical management, may contribute to the progression of CVD. According to recent studies, even middle changes in thyroid hormones levels increase cardiovascular mortality from 20% to 80%. In more details, thyroid disorders seem to have serious effects on the cardiovascular system via plenty mechanisms, including dyslipidemia, hypertension, systolic and diastolic myocardial dysfunction, as well endothelial dysfunction. On top of clinical thyroid disorders management, current therapeutics focus on younger patients with subclinical hypothyroidism and elderly patients with subclinical hyperthyroidism.