Pathogenesis of hypertension in patients with primary hypothyroidism

Abstract

Objective. To investigate short-term effects of thyroxin replacement therapy on blood pressure (BP), left ventricular mass index (LVMI), interstitial fluid volume (IFV) and skin vessels resistance in patients with first diagnosed primary hypothyroidism (PH) and past history of arterial hypertension (AH). Design and methods. 49 patients with PH and AH were examined twice: before the therapy onset and after euthyroid state was achieved. All patients underwent daily BP monitoring, echocardiography, body integral rheography and high frequency ultrasound dopplerography of nail ridge arterioles. Results. Decrease in daytime systolic BP by 8.5 (95 % CI: 5.5-11.5) mm Hg, nighttime systolic BP by 5.3 (2.5-8.1) mm Hg, daytime diastolic BP by 3.8 (1.2-6.4) mm Hg, nighttime diastolic BP by 3.5 (0.9-6.1) mm Hg, IFV by 1.5 (0.11-2.91) l, LVMI by 8.5 (1.9-15.0) g/m² and Purselo index by 0.19 (0.05-0.33) units (or 25 % to initial level) were found in patients with PH when euthyroid state was achieved. Conclusion. IFV can play a key role in AH development in patients with PH.