Hipotiroidismul subclinic și boala cardiacǎ ischemicǎ

Abstract

Subclinical hypothyroidism refers to patients who have an elevated thyrotropin (formerly thyroid-stimulating hormone) (TSH) level and a normal free thyroxin (T4) level. The prevalence of subclinical hypothyroidism increases with age, and is about 10% in women older than 70 years and is somewhat lower in men. Controversy persists as to whether screening and treatment of subclinical hypothyroidism is warranted, because evidence about the benefits and the risks is limited. Subclinical hypothyroidism has been associated with higher levels of some cardiovascular risk factors. Despite some conflicting results, many studies found that subjects with subclinical hypothyroidism have higher total cholesterol and low-density lipoprotein cholesterol levels than euthyroid subjects. A crosssectional study showed that subjects with subclinical hypothyroidism have increased C-reactive protein values. Subclinical hypothyroidism has been associated with increased risk for atherosclerosis. Subclinical hypothyroidism has also been associated with diastolic and systolic cardiac dysfunction, and T4 replacement improves cardiac function in subjects with subclinical hypothyroidism.