Studies of impaired aldosterone response to spironolactone-induced renin and potassium elevations in adenomatous but not hyperplastic primary aldosteronism

The Management of Primary Aldosteronism: Case Detection, Diagnosis, and Treatment: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To develop clinical practice guidelines for the management of patients with primary aldosteronism.

PARTICIPANTS

The Task Force included a chair, selected by the Clinical Guidelines Subcommittee of the Endocrine Society, six additional experts, a methodologist, and a medical writer. The guideline was cosponsored by American Heart Association, American Association of Endocrine Surgeons, European Society of Endocrinology, European Society of Hypertension, International Association of Endocrine Surgeons, International Society of Endocrinology, International Society of Hypertension, Japan Endocrine Society, and The Japanese Society of Hypertension. The Task Force received no corporate funding or remuneration.

EVIDENCE

We searched for systematic reviews and primary studies to formulate the key treatment and prevention recommendations. We used the Grading of Recommendations, Assessment, Development, and Evaluation group criteria to describe both the quality of evidence and the strength of recommendations. We used "recommend" for strong recommendations and "suggest" for weak recommendations.

CONSENSUS PROCESS

We achieved consensus by collecting the best available evidence and conducting one group meeting, several conference calls, and multiple e-mail communications. With the help of a medical writer, the Endocrine Society's Clinical Guidelines Subcommittee, Clinical Affairs Core Committee, and Council successfully reviewed the drafts prepared by the Task Force. We placed the version approved by the Clinical Guidelines Subcommittee and Clinical Affairs Core Committee on the Endocrine Society's website for comments by members. At each stage of review, the Task Force received written comments and incorporated necessary changes.

CONCLUSIONS

For high-risk groups of hypertensive patients and those with hypokalemia, we recommend case detection of primary aldosteronism by determining the aldosterone-renin ratio under standard conditions and recommend that a commonly used confirmatory test should confirm/exclude the condition. We recommend that all patients with primary aldosteronism undergo adrenal computed tomography as the initial study in subtype testing and to exclude adrenocortical carcinoma. We recommend that an experienced radiologist should establish/exclude unilateral primary aldosteronism using bilateral adrenal venous sampling, and if confirmed, this should optimally be treated by laparoscopic adrenalectomy. We recommend that patients with bilateral adrenal hyperplasia or those unsuitable for surgery should be treated primarily with a mineralocorticoid receptor antagonist.

Mineralocorticoid Receptor Antagonists and Clinical Outcomes in Primary Aldosteronism: As Good as Surgery?

Primary aldosteronism (PA) is detected with increasing frequency in hypertensive patients and is associated with excess cardiovascular, renal, and metabolic complications. For these reasons, appropriate choices for treatment of this endocrine condition are mandatory. Adrenalectomy is safely performed in PA patients when adrenal venous sampling (AVS) demonstrates lateralized aldosterone secretion. AVS, however, is a complex procedure and even among worldwide referral centers there are substantial discrepancies for interpretation of results. Also, in the majority of PA patients with lateralized aldosterone secretion, hypertension may persist after adrenalectomy requiring use of additional antihypertensive agents. Treatment with mineralocorticoid receptor antagonists (MRAs) is currently recommended for PA patients with bilateral adrenal disease, but these agents effectively decrease blood pressure also in patients with unilateral disease, although concern remains for possible sex-related side effects. Prospective studies indicate that MRAs have therapeutic values comparable to surgery in the long-term, inasmuch as they effectively correct metabolic abnormalities and subclinical organ damage and reduce the risk of cardiovascular events and renal disease progression. This article overviews the clinical outcomes obtained in patients with PA with use of MRAs.

Radiofrequency Ablation of Functioning Adrenal Adenomas: Preliminary Clinical and Laboratory Findings

PURPOSE

To evaluate clinical and laboratory findings in patients undergoing radiofrequency (RF) ablation for functioning adrenal adenomas.

MATERIALS AND METHODS

Eleven adult patients, nine with Conn syndrome and two with Cushing syndrome, underwent percutaneous computed tomography-guided RF ablation for benign adrenal neoplasms. Systolic, diastolic, and mean blood pressure and the number of classes of antihypertensive drugs used by each patient were analyzed before and 1, 4, and 12 weeks after the procedure. Serum hormone levels were analyzed within 30 days before and 12 weeks after the procedure.

RESULTS

Of the nine patients with Conn syndrome, eight showed normal serum aldosterone levels after the procedure and one patient had a nodule located very close to the inferior vena cava, resulting in incomplete ablation. The two patients with Cushing syndrome had normal serum and salivary cortisol levels after the procedure. Mean aldosterone concentration at baseline was 63.3 ng/dL ± 28.0 and decreased to 13.3 ng/dL ± 13.5 at 12 weeks postoperatively (P = .008). Systolic, diastolic, and mean blood pressures decreased significantly in the first week after the procedure (P < .001) and remained stable during further follow-up.

CONCLUSIONS

In patients with Conn syndrome or Cushing syndrome, percutaneous RF ablation of functioning adrenal adenomas may result in normalization of hormone secretion, improvement in blood pressure, and reduced need for antihypertensive drugs.

Diagnosis and management of primary aldosteronism: an updated review

Primary aldosteronism (PA) is the most common secondary form of arterial hypertension, with a particularly high prevalence among patients with resistant hypertension. Aldosterone has been found to be associated with cardiovascular toxicity. Prolonged aldosteronism leads to higher incidence of cardiac events, glomerular hyperfiltration, and potentially bone/metabolic sequels. The wider application of aldosterone/renin ratio as screening test has substantially contributed to increasing diagnosis of PA. Diagnosis of PA consists of two phases: screening and confirmatory testing. Adrenal imaging is often inaccurate for differentiation between an adenoma and hyperplasia, and adrenal venous sampling is essential for selecting the appropriate treatment modality. The etiologies of PA have two main subtypes: unilateral (aldosterone-producing adenoma) and bilateral (micro- or macronodular hyperplasia). Aldosterone-producing adenoma is typically managed with unilateral adrenalectomy, while bilateral adrenal hyperplasia is amenable to pharmacological approaches using mineralocorticoid antagonists. Short-term treatment outcome following surgery is determined by factors such as preoperative blood pressure level and hypertension duration, but evidence regarding long-term treatment outcome is still lacking. However, directed treatments comprising of unilateral adrenalectomy or mineralocorticoid antagonists still potentially reduce the toxicities of aldosterone. Utilizing a physician-centered approach, we intend to provide up-dated information on the etiology, diagnosis, and the management of PA.

Treatment of primary aldosteronism

The prevalence of primary hyperaldosteronism approaches 10% of all hypertensive patients, and besides efficient diagnostic procedures, effective treatment is of increasing importance to reverse increased morbidity and mortality. Aldosterone-producing adenoma and unilateral adrenal hyperplasia are amenable to cure by endoscopic adrenalectomy. Bilateral adrenal hyperplasia (micro- or macronodular), which comprises two-thirds of primary hyperaldosteronism, is treated primarily by mineralocorticoid receptor antagonists (starting dose 12.5-25mg/day spironolactone with titration up to 100mg/day, alternatively 50-100mg/day eplerenone). If blood pressure is not normalised by this first-line treatment, additional treatment with potassium-sparing diuretics (amiloride or triamterene) or calcium channel antagonists is necessary. The start of medication should be closely monitored by serum electrolyte and creatinine controls.

Case detection, diagnosis, and treatment of patients with primary aldosteronism: an endocrine society clinical practice guideline

OBJECTIVE

Our objective was to develop clinical practice guidelines for the diagnosis and treatment of patients with primary aldosteronism.

PARTICIPANTS

The Task Force comprised a chair, selected by the Clinical Guidelines Subcommittee (CGS) of The Endocrine Society, six additional experts, one methodologist, and a medical writer. The Task Force received no corporate funding or remuneration.

EVIDENCE

Systematic reviews of available evidence were used to formulate the key treatment and prevention recommendations. We used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) group criteria to describe both the quality of evidence and the strength of recommendations. We used "recommend" for strong recommendations and "suggest" for weak recommendations.

CONSENSUS PROCESS

Consensus was guided by systematic reviews of evidence and discussions during one group meeting, several conference calls, and multiple e-mail communications. The drafts prepared by the task force with the help of a medical writer were reviewed successively by The Endocrine Society's CGS, Clinical Affairs Core Committee (CACC), and Council. The version approved by the CGS and CACC was placed on The Endocrine Society's Web site for comments by members. At each stage of review, the Task Force received written comments and incorporated needed changes.

CONCLUSIONS

We recommend case detection of primary aldosteronism be sought in higher risk groups of hypertensive patients and those with hypokalemia by determining the aldosterone-renin ratio under standard conditions and that the condition be confirmed/excluded by one of four commonly used confirmatory tests. We recommend that all patients with primary aldosteronism undergo adrenal computed tomography as the initial study in subtype testing and to exclude adrenocortical carcinoma. We recommend the presence of a unilateral form of primary aldosteronism should be established/excluded by bilateral adrenal venous sampling by an experienced radiologist and, where present, optimally treated by laparoscopic adrenalectomy. We recommend that patients with bilateral adrenal hyperplasia, or those unsuitable for surgery, optimally be treated medically by mineralocorticoid receptor antagonists.

[Modern pharmacological aspects of hyperaldosteronism therapy]

The prevalence of primary hyperaldosteronism is 5-10% of all hypertensive patients, and clearly above the estimated prevalence in the past. In nearly 30% of patients with therapy resistant hypertension, primary hyperaldosteronism is detected if they are investigated thoroughly. This will result in 1.5 to 2.5 million people in Germany suffering from primary hyperaldosteronism. Besides efficient diagnostic procedures, an effective treatment is of increasing importance. The aldosterone-producing adenoma (Conn's syndrome) is primarily cured by operation, in most cases performed endoscopically. Bilateral hyperplasia, which is found in two-thirds of primary hyperaldosteronism, is treated primarily by mineralocorticoid receptor antagonist: 12.5-50 mg/day spironolactone (in case of anti-androgenic side-effects alternatively by 50-100 mg/day eplerenone). If the blood pressure can not be lowered by this first-line treatment, an additional treatment with potassium-sparing diuretics, calcium-antagonists, ACE-inhibitors or angiotensin-2-antagonists is necessary. The start of medication should be closely monitored by serum electrolyte and creatinine controls.

A review of the medical treatment of primary aldosteronism

PURPOSE

Use of the aldosterone-to-renin ratio (ARR) has suggested that at least one in 10 hypertensive subjects have primary aldosteronism (PA). There is thus a timely need to review the literature for effective drug therapies and to speculate on other therapeutic options by taking into account recent advances in understanding of the PA disease pathophysiological process.

DATA SOURCE

A MEDLINE and EMBASE search of all articles published from the start of the databases until July 1999 and reviews of the bibliographies of textbooks.

STUDY SELECTION

Primary research articles on the medical treatment of PA with emphasis on diagnosis, treatment option, drug dosage, therapeutic response and adverse drug effect.

DATA EXTRACTION

Study design and quality were assessed. Relevant data on diagnostic methodology, drug usage and response were analysed and compared.

DATA SYNTHESIS

A select number of subjects with aldosterone-producing adenoma (APA) can be expected to respond well to surgical treatment For the majority of PA cases especially subjects with idiopathic hyperaldosteronism (IHA), long-term medical treatment is now safe and feasible although no randomized controlled trials have been carried out to date. The best therapeutic response is obtained by directly antagonizing aldosterone at the receptor level using medium to low dose spironolactone and this response can be predicted by a raised ARR. The response to other potassium-sparing diuretics and calcium channel blockers are modest. IHA responds better than angiotensin II-unresponsive APA to angiotensin converting enzyme inhibitors and this may also be true with angiotensin II receptor blockers. The discovery of the aldosterone synthase gene opens up the possibility for gene therapy.

CONCLUSION

The diagnosis of PA allows appropriate management with resultant blood pressure control in many hypertensive subjects who otherwise have resistant hypertension despite multiple drug therapy.

My engagement with steroids: a review

In the course of my studies of patients with mineralocorticoid hypertensive disorders, unusual presentations led to unexpected findings, both clinically and in steroid etiologies and regulation. Unique circumstances permitted early studies in defining the autonomy of the aldosterone-producing adenoma. A chance referral brought the index case of 17 alpha-hydroxylase deficiency to the research center. New techniques were developed in unusual ways to measure the metabolites of deoxycorticosterone (DOC) using an anesthetic agent. Procedural delays were followed by the surreptitious transfer of a patient from one hospital to the research center after a benign DOC-secreting tumor had been removed. The delay of DOC and all 17-deoxysteroids to respond normally to ACTH stimulation suggested a possible second regulator of DOC. This observation led to studies that demonstrated divergent responses between DOC and cortisol in diverse conditions. An unexplained mineralocorticoid form of hypertension with suppression of renin and aldosterone, but normal DOC production, is seen in licorice intoxication. After licorice was discontinued we documented the delay in the recovery of the inhibited cortisol metabolism (14 days) and renin-angiotensin system (4 months). Licorice extract given to normal subjects on low sodium diets with and without ACTH suppression showed similar results. Other factors in licorice may thus be operative in terms of renin and aldosterone suppression.

Long-term treatment of mineralocorticoid excess syndromes

Recognition of the pathogenesis of secondary forms of hypertension is often considered the key to appropriate choice of treatment. We here present the results of a prolonged clinical follow-up (from 1 to 20 years) of a large number of patients with mineralocorticoid excess syndromes (MES), including over 100 patients with primary aldosteronism (PA), 3 cases with dexamethasone-suppressible aldosteronism (DSA), 3 cases of apparent mineralocorticoid excess (AME) Type II, and 4 patients with 17-hydroxylase deficiency (17OHDS). The patients with PA have been divided in two subgroups, one of 69 cases followed between 1973 and 1982, and the second of 37 patients studied between 1983 and 1992; 33 further cases were not evaluated due to poor compliance. In group I, 26 patients underwent surgery (23 unilateral adenoma, 1 primary hyperplasia, 2 bilateral nodular hyperplasia); at 5 years 50% had normal blood pressure, 25% had mild hypertension and 25% had moderate to severe hypertension. Forty-three patients with either adenoma (APA) or idiopathic aldosteronism (IHA) received long-term spironolactone treatment. Among them, 13 required the addition of thiazide and/or beta-blockers, while 13 were switched to an amiloride/thiazide combination (+/- beta blockers) due to side-effects to spironolactone (gynecomastia 6/20 males, menstrual upset or breast pain in 7/23 females). In group II, 12 patients underwent surgery (11 adenoma, 1 primary hyperplasia) with a similar outcome at 3 years as in group I; 25 patients were put on either K canrenoate (11) or Ca++ channel blockers (14) with or without KCl supplementation; in 8 cases these two drugs were combined according to blood pressure levels achieved during the follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification and implications of new types of mineralocorticoid hypertension

200 patients with mineralocorticoid hypertension were studied at the Clinical Study Center. The study of 150 patients with primary aldosteronism revealed five distinct subsets based on their responses to the upright posture, after administration of intravenous saline, deoxycorticosterone acetate, and spironolactone. Two new types were identified--aldosterone producing responsive adenoma (AP-RA) and primary adrenal hyperplasia (PAH). Patients with AP-RA maintained normal physiologic responses to the above maneuvers. Patients with PAH had responses similar to patients with an aldosterone producing adenoma (APA) but no tumor was identified. Both types were cured by unilateral adrenalectomy. There has been no change in subtype in up to 20 years of follow-up. The notion of a continuum from low renin hypertension to APA is not supported. Primary deoxycorticosteronism caused by a benign adrenal adenoma, malignancy and hyperplasia is described. Uniquely, overproduction of the 17-deoxysteroids of the zona fasciculata occurs with normal 17-hydroxy function. After the removal of a benign adenoma the contralateral adrenal gland revealed a delay in the 17-deoxysteroid responses to ACTH in the face of normal cortisol increases. This suggests that an independent pituitary regulator of the 17-deoxypathway may exist. Other hypertensive disorders with excessive deoxycorticosterone production are linked with increases of ACTH and cortisol levels. The hallmarks of primary deoxycorticosteronism are hypertension with hypokalemia, suppression of renin and aldosterone, and overproduction of the 17-deoxysteroids.

Use of the saline infusion test to diagnose the cause of primary aldosteronism

Angiotensin II has a major effect on mineralocorticoid hormone synthesis in patients with idiopathic hyperaldosteronism; it has little or no effect in those with an aldosterone-producing adenoma. To determine if this difference could be of use in clinically separating these two forms of primary aldosteronism, saline infusion tests were performed in 20 patients--14 with surgically proved aldosterone-producing adenoma and six with idiopathic hyperaldosteronism. With the patients receiving a balanced diet containing 120 meq of sodium, 1,250 ml of isotonic saline was infused intravenously between 8 A.M. and 10 A.M. after overnight recumbency. Plasma samples were obtained immediately before and after the infusion. Plasma cortisol level decreased appropriately in both groups, but plasma renin concentration decreased only in those patients with idiopathic hyperaldosteronism (p less than 0.05). Aldosterone and 18-hydroxycorticosterone levels decreased in both groups. To account for the circadian variation in adrenocorticotropin levels during the course of saline infusion, 18-hydroxycorticosterone/cortisol and aldosterone/cortisol ratios were examined. Both ratios increased in every patient with aldosterone-producing adenoma (p less than 0.01 and p less than 0.001, respectively), but these ratios remained unchanged or decreased in the patients with idiopathic hyperaldosteronism. This divergent variation in ratios after saline infusion allows for the differentiation of patients with an aldosterone-producing adenoma from those with idiopathic hyperaldosteronism. In patients with primary aldosteronism, an 18-hydroxycorticosterone/cortisol ratio of less than 3.0 or an aldosterone/cortisol ratio of less than 2.2 after saline infusion is diagnostic of idiopathic hyperaldosteronism.