Endocrine Abstracts

The cardiovascular system (CVS) is one of the major targets of thyroid hormone action.

The thyroid function has a direct effect on heart rate, cardiac output and systemic vascular resistance.

The prevalence of hypothyroidism in the general population is high, particularly in females (9–15%). Overt hypothyroidism is associated with severe cardiovascular manifestations including reduced intravascular volume, increased systemic vascular resistance (SVR), and reduced contractility and cardiac oxygen consumption. Clinical hypothyroidism is associated with premature atherosclerosis and increased prevalence of coronary disease. All manifestations are potentially reversible with thyroid hormone replacement.

We have studied 132 subjects with hypothyroidism admitted in Clinic of Endocrinology Timisoara in period 2011–2012, aged 20–87 years (52.47±12.23 years). They were divided by sex, age, living environment (urban, rural), value of cholesterol, heart rate, BMI, and blood pressure. Data on thyroid status, aortic atherosclerosis, and history of myocardial infarction were obtained at baseline. In the study group 89/132 patients had overt hypothyroidism and 43/132 subclinical hypothyroidism.

The study revealed an increased risk of cardiovascular abnormalities and an increased risk of atherosclerosis. Total cholesterol, triglycerides, and the systolic time intervals (increased SVR) were clearly elevated only in overt hypothyroidism. 27/89 cases with overt hypothyroidism had pericarditis.

The cardiovascular risk is associated with heart disease, but it is also influenced by the patient’s age as well as the severity and duration of hypothyroidism. Close monitoring of thyroid function could be the best option for patients at high risk of progression from subclinical to overt disease.