Thyroid Dysfunction in Patients Admitted in Cardiac Care Unit: Prevalence, Characteristic and Hospitalization Outcomes

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.

Hypothyroidism and the risk of coronary artery disease in Saudi patients

BACKGROUND

Hypothyroidism has been described in the literature as a risk factor for coronary artery disease (CAD). An association between thyroid-stimulating hormone (TSH) levels and CAD has been confirmed. In Saudi Arabia, there has been no study on the relationship between hypothyroidism and CAD. Therefore, the aim of this study was to investigate the prevalence and risk factors of CAD in patients with hypothyroidism.

MATERIALS AND METHODS

This cross-sectional study conducted at King Abdulaziz Medical City in Riyadh (KAMC-R), included 412 adult hypothyroid patients who were followed up between 2013 and 2018. The data was collected on demographics, CAD-related risk factors, and hypothyroidism. In addition, relevant laboratory tests, including thyroid function tests, lipid profile, and hemoglobin A1c, were collected. SPSS version 28.0 was used for data analysis. Categorical data were presented as frequencies and percentages, while mean and standard deviations were computed for the numerical data. Student's t-test used to test statistical significance for numerical variables and Chi- square test was performed to test the differences between categorical variables. Multivariate binary logistic regression was used to determine the effects of gender, BMI, family history (CAD), smoking, hypertension, and TSH on CAD.

RESULTS

Of the 412 hypothyroid patients, 21.8% were diagnosed with CAD, with more prevalence in men (44.15%) than in women (15.4%). About 46% had hypertension, 2.2% were smokers, and 2.4% had family history of CAD. Older age was significantly associated with a higher prevalence of CAD compared to younger age groups. The mean of TSH was significantly higher in CAD patients than non-CAD patients before and at diagnosis with CAD (P < 0.001). For every 1mIU/L increase in the TSH level, the odds of developing CAD increased significantly by 4.8% (P = 0.014). The odds ratios for other CAD risk factors were 3.13 for males, 8.1 for smoking, 2.48 for hypertension, and 9.9 for family history of CAD (P < 0.05).

CONCLUSION

The prevalence of CAD in hypothyroid patients was higher than in the general population. TSH level was significantly associated with CAD. Male gender, older age, smoking, hypertension, family history of CAD, and high TSH level increased the likelihood of developing CAD.