Endocrine hypertension

Abstract

Endocrine causes of hypertension are relatively rare, but their detection offers a real chance for cure. The combination of the patient’s history, physical examination, astute observation, and accurate interpretation of laboratory tests may identify such patients. In practice, it is important to follow a stepwise diagnostic approach with special focus on clinical and laboratory clues, suggesting the possible presence of secondary hypertension. Important physical findings suggestive for endocrine hypertension include the presence of a low to lownormal circulating serum potassium levels (suggestive of mineralocorticoid hypertension), a metabolic syndrome such as central obesity, striae, and bruising, osteoporosis (suggestive of Cushing syndrome); tremor, sweating, or rapid pulse (suggestive of hyperthyroidism or pheochromocytoma); or pallor and diaphoresis (suggestive of pheochromocytoma). The most common causes of endocrine hypertension are excess production of mineralocorticoids, glucocorticoids, and catecholamines. The physio-pathological mechanisms of endocrine hypertension encompass hormonal excess secretion by a tumor or hyperplasia, respectively, deficiencies of key enzymes in hormonal synthesis and mutations altering receptor or ion channel function. Although many tests are available for biochemical testing, the diagnostic potential of many tests have not vigorously been examined prospectively in large-scale studies. One should be aware that some of the tests are appropriate for screening purposes, but not for confirming the diagnosis. Furthermore, treatment with different medications may interfere with these tests. As a general rule, in the diagnostic process of endocrine hypertension biochemical diagnosis always precedes imaging studies.