Blood Pressure, Thyroid-Stimulating Hormone, and Thyroid Disease Prevalence in Primary Aldosteronism and Essential Hypertension

BACKGROUND: A positive correlation between thyroid-stimulating hormone (TSH) and blood pressure (BP) has been identified in normotensives and in patients with essential hypertension (EH). This study was designed to evaluate, in primary aldosteronism (PA) and in EH, potential association of BP, TSH, and ultrasonographic changes of the thyroid. METHODS: We studied 188 patients: 92 with PA and 96 matched essential hypertensives. Clinical and ambulatory BP (ABP), and thyroid function were evaluated in all patients. In PA and in a subgroup of EH patients (n = 65) thyroid ultrasonography was performed. RESULTS: In PA patients, diastolic office and diastolic ABP increased across TSH quartiles and multivariate analysis confirmed a positive significant correlation between TSH and diastolic BP, independently of aldosterone levels, body mass index (BMI), duration of hypertension, and age. In EH patients, we found a significant linear increase in systolic and diastolic ABP with increasing TSH. The prevalence of thyroid dysfunctions was similar in PA and EH (15% and 19%, respectively). In PA patients, we found a higher prevalence of ultrasonographic alterations than in EH (66% vs. 46%, P < 0.05). PA patients presenting morphological abnormalities had higher homeostasis model assessment-insulin resistance levels than patients with normal gland at ultrasonography (4.2 ± 1.8 vs. 3.1 ± 0.8 P < 0.05). CONCLUSIONS: We found a positive correlation between TSH and BP both in PA and EH patients. Moreover, in PA patients we observed a high prevalence of thyroid morphological alterations.