Hypothyroidism has been recognized as a cause of secondary hypertension.
Previous studies on the prevalence of hypertension in subjects with hypothyroidism have demonstrated elevated diastolic blood pressure values. (hypertension in ~30% of patients)
In hypothyroidism, there is endothelial dysfunction and arterial smooth muscle compliance is reduced => leads to increased Systemic Vascular Resistance (SVR).
This appears to be a multi-factorial mechanism (increased adrenergic activity and reduction in endothelial-derived relaxation factor (EDRF) availability).
- Klein, I and Danzi, S. Thyroid Disease and the Heart. Circulation. 2007;116:1725-1735.
- Klein I, Ojamaa K. Thyroid hormone and the cardiovascular system. N Engl J Med. 2001;344(7):501.
- Taddei S, Caraccio N, Virdis A, Dardano A, Versari D, Chiadoni L, Salvetti A, Ferrannini E, Monzani F. Impaired endothelium-dependent vasodilatation in subclinical hypothyroidism: beneficial effect of levothyroxine therapy. J Clin Endocrinol Metab. 2003; 88: 3731–3737.