Diagnosing endocrine hypertension: a practical approach

Endocrine Hypertension: The Urgent Need for Greater Global Awareness

Hypertension affects about 1.28 billion adults globally, and significantly increases the risk of chronic morbidity and mortality among sufferers. About 15% of these individuals have secondary hypertension, the majority of whom have dysfunction of one or more endocrine systems as the cause of hypertension. Although adrenal disorders are often identified as the cause of endocrine hypertension, extra-adrenal disease and pituitary disorders also can cause the disease. Timely diagnosis is of paramount importance, because of the potential for a surgical cure or optimal disease control with pharmacotherapy to prevent hypertensive complications. Even with its relatively high prevalence compared with many other chronic illnesses, the diagnosis of endocrine hypertension is often delayed or never made because of poor awareness about the disease among physicians. This review attempts to provide an overview of the disease, with some practical aspects of diagnosis and management of a few of the important disorders causing endocrine hypertension.

The Therapeutic Intensity Score as Predictor of Clinical Outcomes after Total and Partial Adrenalectomy for Unilateral Primary Aldosteronism: Results of a Multicentric Series

BACKGROUND

To evaluate the ability of therapeutic intensity score (TIS) in predicting the clinical outcomes of partial (PA) and total adrenalectomy (TA) for UPA.

METHODS

Between 2011 and 2022, a four-center adrenalectomy dataset was queried for "unilateral adrenal mass" and "UPA" (n = 90). Preoperative TIS of each antihypertensive medication were individually calculated and merged to create a single, cumulative variable. Probability of complete clinical, partial, and absent pooled success rates according to TIS were assessed for the overall cohort by Kaplan-Meier. Cox analyses were used to identify predictors of complete clinical and partial/absent success, respectively. For all analyses, a two-sided p < 0.05 was considered significant.

RESULTS

At a median follow-up of 42 months (IQR 27-54) complete partial, and absent clinical success were observed in 60%, 17.7%, and 22.3%, respectively. On Kaplan-Meier analysis, TIS < 1 predicted higher complete success rates (p < 0.001), while TIS ≥ 1 was predictor of either partial and absent clinical success (p = 0.008). On multivariable analysis, TIS < 1 (HR 0.25; 95% CI 0.11-0.57; p = 0.001) and adenoma size (HR 1.11; 95% CI 1-1.23; p = 0.0049) were independent predictors of complete clinical success, while TIS ≥ 1 (HR 2.84; 95% CI 1.32-6.1; p = 0.007) was the only independent predictor of absent clinical success.

CONCLUSIONS

TIS score and adenoma size may help to identify patients who are likely to be at risk of persistent hypertension after surgery.

Mechanistic insights into the primary and secondary alterations of renal ion and water transport in the distal nephron

The kidneys, by equilibrating the outputs to the inputs, are essential for maintaining the constant volume, pH, and electrolyte composition of the internal milieu. Inability to do so, either because of internal kidney dysfunction (primary alteration) or because of some external factors (secondary alteration), leads to pathologies of varying severity, leading to modification of these parameters and affecting the functions of other organs. Alterations of the functions of the collecting duct (CD), the most distal part of the nephron, have been extensively studied and have led to a better diagnosis, better management of the related diseases, and the development of therapeutic tools. Thus, dysfunctions of principal cell-specific transporters such as ENaC or AQP2 or its receptors (mineralocorticoid or vasopressin receptors) caused by mutations or by compounds present in the environment (lithium, antibiotics, etc.) have been demonstrated in a variety of syndromes (Liddle, pseudohypoaldosteronism type-1, diabetes insipidus, etc.) affecting salt, potassium, and water balance. In parallel, studies on specific transporters (H⁺ -ATPase, anion exchanger 1) in intercalated cells have revealed the mechanisms of related tubulopathies like distal renal distal tubular acidosis or Sjögren syndrome. In this review, we will recapitulate the mechanisms of most of the primary and secondary alteration of the ion transport system of the CD to provide a better understanding of these diseases and highlight how a targeted perturbation may affect many different pathways due to the strong crosstalk and entanglements between the different actors (transporters, cell types).

Hypertension Management in Stroke Prevention: Time to Consider Primary Aldosteronism

Primary aldosteronism confers a higher risk of stroke, atrial fibrillation, and cardiovascular disease than blood pressure matched essential hypertension. It is the most common endocrine cause of secondary hypertension with prevalence estimates of up to 13% in primary care and 30% in referral centers around the world. Unlike essential hypertension, primary aldosteronism has targeted medical treatment and potentially curative surgical solutions which can ameliorate the associated cardiovascular risks. This narrative review highlights an evidence gap in the optimal diagnosis and targeted treatment of primary aldosteronism in secondary stroke prevention. Over half of the patients suffering a stroke have blood pressure in the hypertensive range and less than a third achieve optimal blood pressure control. There are no guideline recommendations to test for primary aldosteronism in these patients, although up to 30% of patients with resistant hypertension may have this disease. The accurate diagnosis of primary aldosteronism could significantly improve blood pressure, simplify the medication regimen and reduce the overall cardiovascular risk in these patients. The challenges associated with screening for primary aldosteronism following stroke may be overcome by novel blood tests which are less affected by antihypertensive medications routinely used in stroke care. Approximately one-quarter of all strokes occur in patients who have previously had a stroke. Modifying hypertension, the leading modifiable risk factor, would, therefore, have significant public health implications. As clinicians, we must increase our awareness of primary aldosteronism in patients with stroke, particularly in those with resistant hypertension, to enable targeted therapy and reduce the risk of stroke recurrence.

Endocrine hypertension secondary to adrenal tumors: clinical course and predictive factors of clinical remission

PURPOSE

Endocrinopathies constitute ~ 10% of secondary hypertension (SH) etiologies. Primary aldosteronism, pheochromocytoma (PHEO), and Cushing's syndrome are common causes. Early identification and treatment result in resolution/improvement of SH. The aim of this study was to characterize the clinical course, outcomes, and remission-associated prognostic factors of SH related to adrenal tumors.

METHODS

Retrospective cohort study including patients with SH who underwent adrenalectomy from 2000 to 2019. Postoperative outcomes were analyzed. Remission was defined as normalization of blood pressure without drug use.

RESULTS

Eighty-three patients with SH were included. Mean ± SD age was 38.8 ± 14.2 years and 75.9% were women. Diagnosis was PHEO in 35 patients (42.2%), aldosteronoma (APA) in 28 (33.7%), cortisol producing adenoma (CPA) in 16 (19.3%), and ACTH-dependent Cushing's in 4 (4.8%). Laparoscopic adrenalectomy was performed in 81 (97.6%) patients. Mean ± SD follow-up was 57.4 ± 49.6 months (range 1-232). Surgical morbidity occurred in 7.2% of patients and there was no mortality. Remission of SH occurred in 61(73.5%): 100% of ACTH-dependent Cushing's, 85.7% of PHEO, 68.8% of CPA, and 57.1% of APA. Biochemical phenotype and the combination of larger tumor size, number of antihypertensive drugs, male gender, older age, obesity, and preoperative SH for more than 5 years were associated with less likely clinical remission in patients with APA (p = 0.004), CPA (p < 0.0001), and PHEO (p < 0.0001).

CONCLUSION

SH remission rates are 57-100% after adrenalectomy. Several prognostic factors could be used to predict SH control. Adrenalectomy provides good clinical outcome and must be considered a treatment option in all surgical candidates.

Comparison of ambulatory blood pressure between patients with primary aldosteronism and other forms of hypertension

OBJECTIVE

Primary aldosteronism (PA) is a potentially curable cause of hypertension associated with worse cardiovascular prognosis than blood pressure-matched essential hypertension (EH). Effective targeted treatment for PA is available with the greatest benefit seen if treatment is started early, prior to the development of end-organ damage. However, PA is currently substantially under-diagnosed. The standard screening test for PA, the aldosterone-to-renin ratio (ARR), is performed infrequently in both primary and tertiary care. In contrast, ambulatory blood pressure monitoring (ABPM) is frequently utilized in the assessment of hypertension. The aim of this study was to compare ABPM parameters in hypertensive patients with and without PA, in order to identify features of ABPM associated with PA that can prompt screening.

STUDY DESIGN

Patients with PA (n = 55) were identified from a tertiary clinic specializing in the management of endocrine causes of hypertension whilst the controls (n = 389) were consecutive patients with hypertension but without a known diagnosis of PA who were referred for ABPM.

RESULTS

In this study, PA patients were younger and had higher 24-h, day, and night-time blood pressure compared with controls despite similar number of antihypertensive medications. However, there was no significant difference in nocturnal dipping or day-night blood pressure variability between the two groups.

CONCLUSIONS

An elevated ambulatory blood pressure in patients on multiple antihypertensives could suggest underlying PA but in the absence of other distinguishing features, ABPM could not reliably differentiate PA from other forms of hypertension. Routine biochemical screening for PA remained the most reliable way of detecting this treatable secondary cause of hypertension.

Primary aldosteronism is a public health issue: challenges and opportunities

A significant proportion of hypertension (potentially more than 5% in the general population) is due to primary aldosteronism (PA) which carries a worse prognosis when compared with blood pressure-matched essential hypertension. Effective targeted treatments are available which mitigate many of the cardiovascular complications of untreated PA. Despite this, the detection rate of PA in primary care is sub-optimal. In this review, we explore the challenges contributing to the under-diagnosis of PA in the community, including uncertainties regarding its actual prevalence. In order to detect PA early and offer targeted treatment before adverse cardiovascular consequences develop, routine screening for PA at the time of a diagnosis of hypertension would seem desirable. However, this is limited by a lack of studies to establish whether routine screening in primary care is cost-effective. Newer techniques are also being developed which could lessen the complexity of diagnosing PA. Most importantly, a dramatic increase in awareness of PA, as a treatable cause of hypertension, is needed amongst clinicians who manage hypertension.

[The Main Provisions of the International Recommendations on Detection of Endocrine Hypertension]

In 2017 the Endocrine Society issued the Scientific Statement "Screening for Endocrine Hypertension" This document was developed by experts from different medical institutions of USA, Europe and Australia. Herein we present the main provisions of this Statement in the form of brief algorithm for the clinicians' actions for timely detection of secondary endocrine hypertension and rational referral of the patient for confirmational testing.The full text of the Scientific Statement in English is contained in the article. Young WF Jr., Calhoun DA, Lenders JW, Stowasser M, Textor SC. Screening for Endocrine Hypertension: An Endocrine Society Scientific Statement. Endocrine Reviews. 2017; 38 (2):103-122.URL: https://academic.oup.com/edrv/article/38/2/103/3104343.

Adrenocorticotropic Hormone Secreting Pheochromocytoma Underlying Glucocorticoid Induced Pheochromocytoma Crisis

CONTEXT

Pheochromocytomas are hormone secreting tumors of the medulla of the adrenal glands found in 0.1-0.5% of patients with hypertension. The vast majority of pheochromocytomas secrete catecholamines, but they have been occasionally shown to also secrete interleukins, calcitonin, testosterone, and in rare cases adrenocorticotropic hormone. Pheochromocytoma crisis is a life threatening event in which high levels of catecholamines cause a systemic reaction leading to organ failure.

CASE DESCRIPTION

A 70-year-old man was admitted with acute myocardial ischemia following glucocorticoid administration as part of an endocrine workup for an adrenal mass. Cardiac catheterization disclosed patent coronary arteries and he was discharged. A year later he returned with similar angina-like chest pain. During hospitalization, he suffered additional events of chest pain, shortness of breath, and palpitations following administration of glucocorticoids as preparation for intravenous contrast administration. Throughout his admission, the patient demonstrated both signs of Cushing's syndrome and high catecholamine levels. Following stabilization of vital parameters and serum electrolytes, the adrenal mass was resected surgically and was found to harbor an adrenocorticotropic hormone secreting pheochromocytoma. This is the first documented case of adrenocorticotropic hormone secreting pheochromocytoma complicated by glucocorticoid induced pheochromocytoma crisis.

CONCLUSION

Care should be taken when administering high doses of glucocorticoids to patients with suspected pheochromocytoma, even in a patient with concomitant Cushing's syndrome.