Importance of dietary salt restriction for patients with primary aldosteronism during treatment with mineralocorticoid receptor antagonists: The potential importance of post-treatment plasma renin levels

Prediction of endogenous mineralocorticoid receptor activity by depressor effects of mineralocorticoid receptor antagonists in patients with primary aldosteronism

Patients with primary aldosteronism have an increased risk of developing cardiovascular disease. The response to mineralocorticoid receptor antagonists varies among individuals, indicating diverse mineralocorticoid receptor activities in these patients. This study explored the factors linked to the efficacy of blood pressure reduction through mineralocorticoid receptor antagonists in patients with primary aldosteronism. We examined the relationship between the reduction in blood pressure and patient characteristics in a group of 41 patients with primary aldosteronism (24 males, mean age 55 ± 13 years, including 34 patients diagnosed with bilateral primary aldosteronism) before and after undergoing treatment with mineralocorticoid receptor antagonists. Significant reductions in office blood pressure were observed 3 and 6 months after treatment initiation. Single correlation analyses showed that the urinary chloride-to-potassium ratio displayed the strongest positive association with blood pressure reduction, surpassing plasma aldosterone concentration, plasma renin activity, and urinary sodium-to-potassium ratio, at 3 and 6 months. Multiple correlation analyses revealed a consistent and independent positive correlation between the urinary chloride-to-potassium ratio and blood pressure reduction at 3 and 6 months. The optimal threshold for the urinary chloride-to-potassium ratio with respect to its ability to lower blood pressure, was determined as 3.18. These results imply that the urinary chloride-to-potassium ratio may be independently associated with the effectiveness of blood pressure reduction facilitated by mineralocorticoid receptor antagonists. Moreover, it could potentially serve as a valuable predictor of the effectiveness of these agents and function as an indicator of endogenous mineralocorticoid receptor activity in patients with primary aldosteronism.

Moderate salt restriction in primary aldosteronism improves bone metabolism through attenuation of urinary calcium and phosphate losses

Accumulating evidence links osteoporosis and dietary salt consumption. Primary aldosteronism (PA) is a model disease with increased dietary salt intake and constitutes an independent risk factor for osteoporosis. We, thus, assessed whether a short-term moderate reduction in salt intake in PA results in detectable osteoanabolic effects. Forty-one patients with PA on stable mineralocorticoid receptor antagonist therapy were subjected to a 12-week salt restriction. Serum and urinary electrolytes, markers of bone turnover, and a 15 steroids plasma profile were registered. After 12 weeks, urinary calcium and phosphate decreased, while plasma testosterone, serum phosphate, and bone alkaline phosphatase (BAP) all increased significantly. Longitudinal changes in BAP were independently correlated with changes in serum phosphate, parathyroid hormone, and urinary calcium in multivariate analysis. Salt restriction in PA limits urinary calcium and phosphate losses and may confer favorable osteoanabolic effects. Our findings suggest that salt restriction should be considered in patients with PA to improve bone health.

Biomarkers to Guide Medical Therapy in Primary Aldosteronism

Primary aldosteronism (PA) is an endocrinopathy characterized by dysregulated aldosterone production that occurs despite suppression of renin and angiotensin II, and that is non-suppressible by volume and sodium loading. The effectiveness of surgical adrenalectomy for patients with lateralizing PA is characterized by the attenuation of excess aldosterone production leading to blood pressure reduction, correction of hypokalemia, and increases in renin-biomarkers that collectively indicate a reversal of PA pathophysiology and restoration of normal physiology. Even though the vast majority of patients with PA will ultimately be treated medically rather than surgically, there is a lack of guidance on how to optimize medical therapy and on key metrics of success. Herein, we review the evidence justifying approaches to medical management of PA and biomarkers that reflect endocrine principles of restoring normal physiology. We review the current arsenal of medical therapies, including dietary sodium restriction, steroidal and nonsteroidal mineralocorticoid receptor antagonists, epithelial sodium channel inhibitors, and aldosterone synthase inhibitors. It is crucial that clinicians recognize that multimodal medical treatment for PA can be highly effective at reducing the risk for adverse cardiovascular and kidney outcomes when titrated with intention. The key biomarkers reflective of optimized medical therapy are unsurprisingly similar to the physiologic expectations following surgical adrenalectomy: control of blood pressure with the fewest number of antihypertensive agents, normalization of serum potassium without supplementation, and a rise in renin. Pragmatic approaches to achieve these objectives while mitigating adverse effects are reviewed.

Renin as a Biomarker to Guide Medical Treatment in Primary Aldosteronism Patients. Findings from the SPAIN-ALDO Registry

INTRODUCTION

Primary aldosteronism (PA) is associated with several cardiometabolic comorbidities. Specific treatment by mineralocorticoid receptor antagonists (MRA) or adrenalectomy has been reported to reduce the cardiometabolic risk. However, the cardiovascular benefit could depend on plasma renin levels in patients on MRA.

AIM

To compare the development of cardiovascular, renal and metabolic complications between medically treated patients with PA and those who underwent adrenalectomy, taking the renin status during MRA treatment into account.

METHODS

A multicenter retrospective study (SPAIN-ALDO Register) of patients with PA treated at 35 Spanish tertiary hospitals. Patients on MRA were divided into two groups based on renin suppression (n = 90) or non-suppression (n = 70). Both groups were also compared to unilateral PA patients (n = 275) who achieved biochemical cure with adrenalectomy.

RESULTS

Adrenalectomized patients were younger, had higher plasma aldosterone concentration, and lower potassium levels than MRA group. Patients on MRA had similar baseline characteristics when stratified into treatment groups with suppressed and unsuppressed renin. 97 (55.1%) of 176 patients without comorbidities at diagnosis, developed at least one comorbidity during follow-up (median 12 months vs. 12.5 months' follow-up after starting MRA and surgery, respectively). Surgery group had a lower risk of developing new cardiovascular events (HR 0.40 [95% CI 0.18-0.90]) than MRA group. Surgical treatment improved glycemic and blood pressure control, increased serum potassium levels, and required fewer antihypertensive drugs than medical treatment. However, there were no differences in the cardiometabolic profile or the incidence of new comorbidities between the groups with suppressed and unsuppressed renin levels (HR 0.95 [95% CI 0.52-1.73]).

CONCLUSION

Cardiovascular, renal, and metabolic events were comparable in MRA patients with unsuppressed and suppressed renin. Effective surgical treatment of PA was associated with a decreased incidence of new cardiovascular events when compared to MRA therapy.

Salt and Aldosterone - Reciprocal and Combined Effects in Preclinical Models and Humans

Primary aldosteronism is an endocrine disorder caused by excessive production of aldosterone by the adrenal glands, and is recognized as the most important cause of endocrine hypertension. With specific therapy, this type of hypertension is potentially curable. In the general population, high salt intake increases the risk for cardiovascular diseases like stroke. In populations with aldosterone excess, observational and experimental data suggest that aldosterone-induced organ damage requires a combination of high dietary salt intake and high plasma aldosterone, i.e., plasma aldosterone levels inappropriately high for salt status. Therefore, understanding the relationship between plasma aldosterone levels and dietary salt intake and the nature of their combined effects is crucial for developing effective prevention and treatment strategies. In this review, we present an update on findings about primary aldosteronism and salt intake and the underlying mechanisms governing their interaction.

Effects of esaxerenone on blood pressure, urinary albumin excretion, serum levels of NT-proBNP, and quality of life in patients with primary aldosteronism

Primary aldosteronism (PA) is typically managed with mineralocorticoid receptor antagonists (MRAs) barring adrenalectomy. The efficacy of esaxerenone, a nonsteroidal MRA, were explored in patients with PA. Various parameters such as the urinary albumin to creatinine ratio (UACR) and serum levels of N-terminal prohormone of brain natriuretic peptide (NT-proBNP) were evaluated in 25 PA patients before and 3 and 6 months after esaxerenone treatment. Systolic and diastolic blood pressure (BP), and the estimated glomerular filtration rate decreased after treatment, while serum levels of potassium and active renin increased. Significant reductions were observed in UACR 3 and 6 months after treatment. A significant decrease in NT-proBNP was evident at 6 months but not 3 months after treatment. Correlation analysis indicated that the reductions in BP and UACR at 3 months were independent of estimated daily salt intake. Furthermore, the effect of esaxerenone treatment on lowering UACR and NT-proBNP levels was independent of BP reduction. Responders whose systolic BP decreased 6 months after esaxerenone treatment by more than 10 mmHg compared to pretreatment had higher pretreatment NT-proBNP and similar UACR before and after treatment when compared with nonresponders. Esaxerenone improved mental, physical, and social quality of life (QOL) 6 months after treatment compared to healthy controls and increased over time. No patients discontinued treatment due to severe hyperkalemia or renal dysfunction. In conclusion, esaxerenone is a safe and effective MRA for PA treatment, offering significant benefits in terms of hypertension, albuminuria, NT-proBNP levels, and QOL improvement. Esaxerenone effectively lowers BP, UACR, and serum levels of NT-proBNP independent of dietary salt intake in mild PA patients. ARC active renin concentration, DBP diastolic blood pressure, MR mineralocorticoid receptor, MRA mineralocorticoid receptor antagonist, NT-proBNP N-terminal pro-brain natriuretic peptide, PA primary aldosteronism, QOL quality of life, SBP systolic blood pressure, SF-36 Medical Outcomes Study 36-Item Short-Form Health Survey, UACR urinary albumin to creatinine ratio.

2023 update and perspectives

Total 276 manuscripts were published in Hypertension Research in 2022. Here our editorial members picked up the excellent papers, summarized the current topics from the published papers and discussed future perspectives in the sixteen fields. We hope you enjoy our special feature, 2023 update and perspectives in Hypertension Research.

Associations of Diabetic Retinopathy Severity With High Ambulatory Blood Pressure and Suppressed Serum Renin Levels

CONTEXT

The relationships between serum renin levels, severity of diabetic retinopathy (DR), and 24-hour blood pressure (BP) have not been previously reported.

OBJECTIVE

To explore causes for DR and the relationships of 24-hour ambulatory BP, and hormone levels with the severity of DR.

METHODS

The diabetic patients were classified as having no DR, simple DR, or severe DR (preproliferative DR plus proliferative DR) based on funduscopic examination, and we measured 24-hour BP, serum active renin (ARC), aldosterone (SAC), adrenocorticotropic hormone, and cortisol levels in each group.

RESULTS

Compared to those with no DR or simple DR, patients with severe DR showed significantly higher 24-hour BPs, including daytime and nighttime systolic and diastolic BP levels, independent of diabetic duration and HbA1c levels. The variability of nighttime systolic BP was greater in patients with severe DR than in those with nonsevere DR, although nocturnal BP reduction was similar between the groups. The ambulatory BPs were significantly inversely associated with ARC. The ARC was significantly lower in severe DR patients than in those with no DR or simple DR (3.2 [1.5-13.6] vs 9.8 [4.6-18.0] pg/mL, P < .05), but there were no differences in SAC in patients taking calcium channel blockers and/or α-blockers. No associations were found between DR severity and other hormone levels.

CONCLUSION

Severe DR was associated with higher 24-hour BPs and suppressed ARC. These findings suggest that mineralocorticoid receptor overactivation may play a role in higher BP levels and severe DR in diabetic patients.

Primary aldosteronism: Practical recommendations for treatment and follow-up

Primary aldosteronism (PA) is the most common cause of secondary arterial hypertension. For unilateral cases, surgery offers the possibility of cure, with unilateral adrenalectomy being the treatment of choice, whereas bilateral forms of PA are treated mainly with mineralocorticoid receptor antagonists (MRA). The goals of treatment for PA due to either unilateral or bilateral adrenal disease include reversal of the adverse cardiovascular effects of hyperaldosteronism, normalization of serum potassium in patients with hypokalemia, and normalization of blood pressure. The Primary Aldosteronism Surgery Outcome group (PASO) published a study defining clinical and biochemical outcomes based on blood pressure and correction of hypokalemia and aldosterone to renin ratio (ARR) levels for patients undergoing total unilateral adrenalectomy for unilateral PA. In this review, we provide several practical recommendations for the medical and surgical management and follow-up of patients with PA.

Recent progress in the diagnosis and treatment of primary aldosteronism

Primary aldosteronism (PA) is caused by excessive secretion of aldosterone from the adrenal glands, with subsequent changes in the renin-angiotensin system. In Japan, chemiluminescent enzyme immunoassay is currently performed for aldosterone assay rather than the earlier method of radioimmunoassay. This change in aldosterone measurement methods has resulted in faster and more accurate measurement of blood aldosterone levels. Since 2019, esaxerenone, a mineralocorticoid receptor antagonist (MRA) with a non-steroidal skeleton, has been available in Japan for the treatment of hypertension. Esaxerenone has been reported to have various effects, such as strong antihypertensive and anti-albuminuric/proteinuric effects. Treatment of PA with MRAs has been reported to improve the patient's quality of life and to suppress the onset of cardiovascular events independent of their effects on blood pressure. Measuring renin levels is recommended for monitoring the extent of mineralocorticoid receptor blockade during MRA treatment. Patients receiving MRAs are prone to developing hyperkalemia, and combining MRAs with sodium/glucose cotransporter 2 inhibitors is expected to prevent severe hyperkalemia and provide additional cardiorenal protection. Mineralocorticoid receptor-associated hypertension is a broad concept of hypertension that includes not only PA, but also hypertension caused by borderline aldosteronism, obesity, diabetes, and sleep apnea syndrome. New findings on primary aldosteronism, which is part of MR-associated hypertension. Aldosterone measurements have been changed to the CLEIA method. Treatment of primary aldosteronism with MRAs has a variety of positive effects. CT-guided radiofrequency ablation and transarterial embolization are alternatives to surgery for aldosterone-producing adenomas. BP blood pressure, CLEIA chemiluminescent enzyme immunoassay, CT computed tomography, K serum potassium, MR mineralocorticoid receptor, MRA mineralocorticoid receptor antagonist, QOL quality of life, SGLT2i sodium/glucose cotransporter 2 inhibitor.