THYROID FUNCTION AND LARGE ARTERY STIFFNESS WITH ESSENTIAL HYPERTENSION AND ISOLATED OFFICE HYPERTENSION: PP.31.217

Abstract

Objective: The association between hypothyroidism and increased vascular resistance, arterial wall thickening and endothelial dysfunction is well recognized. The aim of this study was to assess possible associations between thyroid hormones within normal levels and arterial stiffness in essential hypertensive patients versus patients with isolated office hypertension and healthy controls. Design and Methods: The study comprised 1445 patients with essential hypertension (n = 880), isolated office hypertension (n = 388) and healthy controls (n = 177), all with normal thyroid function. The study participants underwent full clinical and biochemical evaluation. Thyroid function was evaluated with the measurement of serum T3, T4, TSH, FT3 and FT4. Aortic stiffness and arterial wave reflection assessment were evaluated with carotid femoral (PWVc-f) and carotid radial (PWVc-r) pulse wave velocity and aortic augmentation index corrected for heart rate (Aix75). Results: In patients with arterial hypertension, regression analysis revealed that TSH, FT3, FT4 levels are determinants of PWVc-r [(beta (SE) = -0.079 (0.038), p = 0.039), (beta (SE) = 0.281 (0.101), p = 0.005), (beta (SE) = 0.595 (0.209), p = 0.005), respectively] and additionally all thyroid hormones T3[beta (SE) = 0.399 (0.197), p = 0.0043], T4 [beta (SE) = 0.071 (0.032), p = 0.027], TSH [beta (SE) = -0.8 (0.041), p = 0.049], FT3 [beta (SE) = 0.253 (0.107) p = 0.018] and FT4 [beta (SE) = 1.277 (0.222) p < 0.001] are predictive for PWVc-f. Furthermore, T4 [beta (SE) = 0.812 (0.253) p = 0.001] and TSH [beta (SE) = -0.751 (0.32) p = 0.019] determined AIx75. Finally in patients with isolated office hypertension only FT4 [beta (SE) = 0.71(0.295) p = 0.017] was independently predictive of PWVc-f. Conclusions: There seems to be an independent association between thyroid hormones, within normal values, and arterial stiffness indices in essential hypertensive patients. Thus, even mild changes in thyroid hormone levels may affect large artery properties.