[Current diagnosis of secondary hypertension associated with the endocrinopathies].

Secondary hypertension is an elevated blood pressure resulting from an underlying and identifiable cause. Only about 5 to 10 percent of hypertension cases are thought to result from secondary causes. Primary aldosteronism (PA) and Cushing's syndrome are typical endocrinopathies developing this type of hypertension. Herein, the updated diagnostic guidelines for these diseases and some problems arising from them are reviewed. Hypertensive patients diagnosed with PA have been increasing significantly based on screening tests using the aldosterone-renin ratio (ARR). We usually suspect hypertensive patients with an ARR of 20 or more as having PA, and plan confirmatory tests, such as captopril, furosemide-upright, saline-loading, and rapid ACTH tests. Although the diagnosis of PA is not complicated endocrinologically, it is sometimes difficult to decide on the laterality of the adrenal lesion. Aldosterone-producing adenoma (APA) is sometimes too small to detect and indistinguishable from non-functional nodules on CT. Therefore, adrenal venous sampling (AVS) is reliable for the lateralization of PA. Cushing's syndrome is involved in refractory hypertension. Because hypertension associated with this syndrome could be improved markedly through treatment of the primary lesion, it is important to diagnose it at an early stage. To detect this syndrome simply and correctly, the measurement of salivary cortisol (sF), as a substitute for plasma cortisol (pF), has recently been paid attention. In our studies, it was demonstrated that midnight sF was closely correlated with midnight pF. This suggests that midnight sF can be useful in the diagnosis of Cushing's syndrome. Herein, the sensitivity and specificity of this examination in our cases are discussed.