Background: Hashimoto's thyroiditis (HT) is an autoimmune disorder associated with increased cardiovascular risk, mainly as a result of accelerated atherosclerosis. The aim of this study was to determine the effect of HT on carotid atherosclerosis and arterial stiffness, as possible mediators of this vascular impairment. Menopausal status was also considered in this setting since HT is mainly prevalent in women.
Methods: Fifty-four women with HT and normal thyroid function (thyrotropin [TSH] < 4.5 mU/L) and 72 healthy controls with comparable age and risk factor prevalence were examined in this cross-sectional study. Intima-media thickness (IMT) in the carotid arteries averaged from six sites and carotid-femoral pulse wave velocity (PWV) were measured.
Results: Although both groups had TSH levels within normal limits, TSH was higher in HT patients (2.1 +/- 1.16 vs. 1.5 +/- 0.8 mU/L, p = 0.001). PWV (7.95 +/- 2.02 vs. 7.21 +/- 1.24 m/s, p = 0.021), but not IMT (0.644 +/- 0.144 vs. 0.651 +/- 0.169 mm, p = 0.798), was significantly higher in HT patients compared to controls. When the women were divided according to menopausal status, only premenopausal women without HT had significantly lower PWV when compared with the three other subgroups (6.51 +/- 1.09 m/s premenopausal controls vs. 7.64 +/- 2.05 m/s premenopausal HT vs. 7.69 +/- 1.11 m/s postmenopausal controls vs. 8.3 +/- 1.97 m/s postmenopausal HT, p < 0.001). By multivariate analysis PWV independently correlated with age (p = 0.042), the presence of HT (p = 0.002), TSH (p = 0.003), and menopause (p < 0.001) in the whole population while HT was an independent determinant of PWV only in premenopausal women.
Conclusions: HT is associated with increased PWV independent of arterial atheromatosis, indicating a direct impact of this disorder on arterial stiffening. This effect may be masked in postmenopausal women possibly due to their heavier cardiovascular risk profile.