Prediction of Successful Outcome in Patients with Primary Aldosteronism
Primary aldosteronism is one of the most common causes of secondary hypertension. In recent years the prevalence has risen dramatically, from 1% to 14% of all hypertensive patients. This has been largely attributed to an increase in diagnosis. Primary aldosteronism is characterized by hypertension with or without hypokalemia and a high plasma aldosterone concentration (PAC) with a concurrent low plasma renin activity (PRA). The most common subtypes of primary aldosteronism are aldosterone-producing adenoma (42%) and bilateral idiopathic hyperaldosteronism (58%). Other less common subtypes (<1%) are glucocorticoid-remediable aldosteronism, and unilateral primary hyperplasia. Current treatment for primary aldosteronism relies on accurate subtype distinction and assessment of unilateral versus bilateral disease. Bilateral idiopathic hyperaldosteronism is best managed pharmacologically and improves with the use of aldosterone receptor antagonists. Combined treatment with sodium-channel blockers and calcium-channel blockers has also shown satisfactory results. Glucocorticoid-remediable aldosteronism responds well to treatment with low-dose glucocorticoids. Aldosterone producing adenoma and unilateral adrenal hyperplasia are appropriately treated with laparoscopic adrenalectomy. Following adrenalectomy blood pressure improves in 98% of these patients, but only about 33% require no further antihypertensive medication. Identifying the subgroups that will most benefit from adrenalectomy is paramount to formulating individual treatment strategies. In the past, treatment focused mainly on the correction of hypertension and electrolyte disturbances. Now, with accumulating evidence of the detrimental effects of aldosterone to the myocardium, vascular endothelium and kidneys, treatment also focuses on normalizing aldosterone levels or blocking aldosterone action at the receptor level. Therefore, it is essential to accurately identify the specific subtype of primary aldosteronism in order to select optimal treatment and to achieve successful patient outcomes.
- [Show abstract] [Hide abstract] ABSTRACT: Objective: To investigate the discrepancy of aldosterone synthesis process and potential regulation abnormality between aldosterone-producing adenoma (APA) and normal adrenal (NA) with microarray. Methods: cRNA probes labelled with biotin were prepared from mRNA of APAs (APA group, n = 10) or NAs (control group, n = 7). The probes were hybridized with oligonucleotide microarray of target gene expression profile. Expression levels were read from the fluorescent intensity scanned. The difference of gene expression profile was analyzed by computer software. Differentially expressed genes were verified by real-time RT-PCR. Results: Compared with control group, 97 genes were up-regulated and 168 genes were down-regulated in APA group. In the genes related to steroid hormone synthesis, only CYP11B2 was significantly up-regulated. In the physiologic regulators of aldosterone synthesis, CYB5A, CYP17A1, DUSP1 and HMGCR were down-regulated, while RENBP and NR1H2 were up-regulated. As a key enzyme in the biosynthesis of cortisol, the expression of CYP17A1 gene was inhibited. Conclusion: Among the aldosterone synthesis related enzyme and corresponding regulatory genes in APA, CYP11B2 may be a key synthetase, and the suppressed physiologic regulators of aldosterone synthesis may indicate the existence of neoplastic modulation.0Comments 1Citation
- [Show abstract] [Hide abstract] ABSTRACT: Primary hyperaldosteronism is one of the most frequent causes of secondary hypertension. Cardiovascular morbimortality is higher than in essential hypertonic and justifies diagnostic and specific treatment of this pathology. Therapeutic choice depends of health and desire of the patient. It is either medical with mineralocorticoid receptor antagonists, or surgical through adrenalectomy. In this case, a pre-surgery exam including a radiologic examination and a venous adrenal catheterism has to be done. Surgery allows a normalisation of kaliema and a blood pressure decrease in 50 to 88% of the patients. Beyond them, 30% are able to stop entirely their medication. Both therapeutic choices decrease cardiovascular risks equally if blood pressure is controlled.0Comments 0Citations