Cardiovascular risk with subclinical hyperthyroidism and hypothyroidism: pathophysiology and management.

Previous studies have suggested that subclinical thyroid dysfunction, as manifested by abnormalities in thyroid-stimulating hormone (TSH) levels, are associated with detrimental effects on the cardiovascular system. Subclinical hypothyroidism is characterized by abnormal lipid metabolism, cardiac dysfunction, diastolic hypertension conferring an elevated risk of atherosclerosis, and ischemic heart disease. Similarly, patients with subclinical hyperthyroidism have nearly 3 times the likelihood of atrial fibrillation over a 10-year follow-up interval, raising the question of whether patients with subclinical hyperthyroidism should be treated to prevent atrial fibrillation.

Impact of subclinical thyroid disorders on coronary heart disease, cardiovascular and all-cause mortality: a meta-analysis.

Background: Previous studies have suggested that sub-clinical thyroid states may have detrimental effects on the coronary heart disease (CHD). Whether subclinical thyroid dysfunction is a risk factor for the above is controversial.

Methods: A systemic search of the literature using Pubmed, Medline and Ovid online tool was performed to identify relevant studies.