Endokrine Hypertonie: Wie diagnostizieren?

Endocrine Hypertension: Diagnostic Approaches. Endocrine diseases are the most common secondary forms of hypertension. Because of its high prevalence (5–13 % in hypertension), primary hyperaldosteronism is most important in this context. Diagnosis of this entity is recommended in hypokalemic hypertension, in therapy-resistant hypertension (≥ 3 drugs and RR > 140/90 mmHg), in strong hypertension (RR > 160/100), in younger patients < 30 years and in adrenal incidentalomas (= incidentally discovered adrenal tumours). For screening, the ratio between the plasma aldosterone (PAC) and plasma renin concentrations (PRC) should be measured. In the assessment of the PAC/PRC ratio, the discontinuation of some antihypertensive medication and assay-specific cut-off values must be noticed. After a positive screening test, a saline infusion test should be done as a confirmatory test. If this test is contraindicated or impracticable, 24-h urine collection for aldosterone-18-glucuronid applying a high-sodium diet can be used as an alternative confirmatory test. After confirmation of primary hyperaldosteronism differential diagnosis between aldosterone-producing adenomas and idiopathic hyperaldosteronism has to be done. For this approach, adrenal CT or MRT and adrenal vein catheterization as gold standard tests are available. Pheochromocytoma is a more uncommon cause of hypertension, but must not be overlooked because of an increased mortality and frequently underlying genetic disorders. Besides clinical hints (sudden crises of hypertension and tachycardia, headache), the determination of free metanephrines in plasma is an easy and valid screening test. Additional biochemical tests are catecholamines and metanephrines in 24-h urine, the clonidine test, and serum chromoganin. After (!) biochemical confirmation of pheochromocytoma, tumour search is done by adrenal CT or MRT, MIBG szintigraphy, or fluoro-dopa-PET. J Klin Endokrinol Stoffw 2012; 5 (2): 22–8.