Nocturia and obstructive sleep apnoea

Nocturia, the need to urinate at night, is a common symptom in patients with obstructive sleep apnoea (OSA). Continuous positive airway pressure treatment can reduce nocturia in some patients, but the underlying mechanisms are complex and not fully understood. OSA affects the autonomic nervous system, oxidative stress and endothelial damage. Furthermore, the commonly held theory attributing polyuria to a false signal of cardiac overload and response natriuresis has limitations. A comprehensive approach to the management of nocturia in OSA, considering factors such as comorbidities, medication use, alcohol consumption and lifestyle, is needed. Effective management of nocturia in OSA requires a multidisciplinary approach, and urologists should be aware of the potential effect of OSA on physiology and refer patients for further testing at a sleep centre. In addition to continuous positive airway pressure, other interventions such as oral appliances and surgical obstruction treatment could be beneficial for some patients. Overall, understanding the complex interplay between OSA and nocturia is crucial for optimizing patient outcomes.

Screening parameters for diagnosing primary aldosteronism in patients with moderate to severe obstructive sleep apnea hypopnea syndrome and resistant hypertension

Background

Patients with obstructive sleep apnea hypopnea syndrome (OSAHS) combined with resistant hypertension (RH) have a high risk of developing primary aldosteronism (PA). This study investigated the aldosterone-renin ratio (ARR), plasma aldosterone concentration (PAC), and plasma renin activity (PRA) to determine the optimal cutoff values for PA diagnosis in patients with OSAHS combined with RH.

Methods

Patients diagnosed with moderate and severe OSAHS combined with RH were recruited from the inpatient clinic of the Department of Endocrinology at Ji'an Central Hospital between October 2020 and April 2023. The included patients were divided into PA and no-PA groups. Diagnostic accuracy measures were calculated for each group, and receiver operating characteristic (ROC) curves were generated.

Results

A total of 241 patients were included, of which 103 had positive ARR screening results in the diagnostic accuracy analysis and 66 were diagnosed with PA. PAC and ARR showed moderate predictive capacity for PA, with area under the curve (AUC) values of 0.66 [95% confidence interval (CI): 0.55-0.77] and 0.72 (95% CI: 0.63-0.82), respectively, while PRA exhibited a limited predictive capacity (AUC = 0.51, 95% CI: 0.40-0.63). Using 45 as the optimal cutoff value for ARR, the sensitivity was 86% and the specificity was 52%. The optimal cutoff value for PAC was 17, with a sensitivity of 78% and a specificity of 55%. Notably, in patients with severe OSAHS, ARR at screening demonstrated significant predictive value for PA, with an AUC of 0.84 (95% CI: 0.72-0.96), a sensitivity of 85%, and a specificity of 76%. Conversely, in patients with moderate OSAHS, only ARR demonstrated significant predictive value for PA diagnosis, while PAC did not demonstrate notable diagnostic value.

Conclusion

ARR and PAC are initial screening tools for PA, facilitating early detection, particularly in low-resource settings. In patients with OSAHS and RH, the ARR and PAC thresholds for PA diagnosis may require more stringent adjustment.

Adverse Effects of Aldosterone: Beyond Blood Pressure

Aldosterone is a steroid hormone that primarily acts through activation of the mineralocorticoid receptor (MR), a nuclear receptor responsible for downstream genomic regulation. Classically, activation of the MR in the renal tubular epithelium is responsible for sodium retention and volume expansion, raising systemic blood pressure. However, activation of the MR across a wide distribution of tissue types has been implicated in multiple adverse consequences for cardiovascular, cerebrovascular, renal, and metabolic disease, independent of blood pressure alone. Primary aldosteronism, heart failure, and chronic kidney disease are states of excessive aldosterone production and MR activity where targeting MR activation has had clinical benefits out of proportion to blood pressure lowering. The growing list of established and emerging therapies that target aldosterone and MR activation may provide new opportunities to improve clinical outcomes and enhance cardiovascular and renal health.

Screening and diagnosis of primary aldosteronism. Consensus document of all the Spanish Societies involved in the management of primary aldosteronism

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension (HT), and is associated with a higher cardiometabolic risk than essential HT. However, PA remains underdiagnosed, probably due to several difficulties clinicians usually find in performing its diagnosis and subtype classification. The aim of this consensus is to provide practical recommendations focused on the prevalence and the diagnosis of PA and the clinical implications of aldosterone excess, from a multidisciplinary perspective, in a nominal group consensus approach by experts from the Spanish Society of Endocrinology and Nutrition (SEEN), Spanish Society of Cardiology (SEC), Spanish Society of Nephrology (SEN), Spanish Society of Internal Medicine (SEMI), Spanish Radiology Society (SERAM), Spanish Society of Vascular and Interventional Radiology (SERVEI), Spanish Society of Laboratory Medicine (SEQC(ML)), Spanish Society of Anatomic-Pathology, Spanish Association of Surgeons (AEC).

Who needs to be screened for primary aldosteronism?

The prevalence of patients with primary aldosteronism (PA) is about 5%-15% in hypertensive patients, and it is common cause of secondary hypertension in clinical practice. Two major causes of PA are noted, namely bilateral adrenal hyperplasia and aldosterone-producing adenoma, and the general diagnosis is based on three steps: (1) screening, (2) confirmatory testing, and (3) subtype differentiation (Figure 1). The recommendation for screening patients is at an increased risk of PA, here we focus on which patients should be screened for PA, not only according to well-established guidelines but for potential patients with PA. We recommend screening for 1) patients with resistant or persistent hypertension, 2) hypertensive patients with hypokalemia (spontaneous or drug-induced), 3) young hypertensive patients (age <40 years), and 4) all hypertensive patients with a history of PA in first-degree relatives. Moreover, we suggest screening for 1) hypertensive patients themselves or first-degree relatives with early target organ damage, such as stroke and other diseases, 2) all hypertensive patients with a concurrent adrenal incidentaloma, 3) hypertensive patients with obstructive sleep apnea, 4) hypertensive patients with atrial fibrillation unexplained by structural heart defects and/or other conditions resulting in the arrhythmia, 5) hypertensive patients with anxiety and other psychosomatic symptoms, and 6) hypertensive patients without other comorbidities to maintain cost-effectiveness.

Epidemiology and diagnosis of primary aldosteronism. What have we learned from the SPAIN-ALDO registry?

PURPOSE

To summarize the available data on the prevalence, clinical repercussion, and diagnosis of primary aldosteronism (PA) and to discuss the SPAIN-ALDO registry's findings, which is the largest PA patient registry in Spain.

METHODS

A comprehensive review of the literature focused on the prevalence, clinical presentation and diagnosis of PA was performed.

RESULTS

PA is the most common cause of secondary arterial hypertension. In addition, PA patients have a higher cardio-metabolic risk than patients with essential arterial hypertension matched by age, sex, and blood pressure levels. However, despite its high prevalence and associated metabolic and cardiovascular complications, PA remains largely under-recognized, with less than 2% of people in at-risk populations ever tested. The diagnostic investigation is a multistep process, including screening, confirmatory testing, and subtype differentiation of unilateral from bilateral PA forms. Data from the SPAIN-ALDO registry have shed light on the cardiometabolic impact of PA and about the limitations in the PA diagnosis of these patients in Spain.

CONCLUSIONS

The most common cause of secondary hypertension is PA. One of the most challenging aspects of the diagnosis is the differentiation between unilateral and bilateral PA because adrenal venous sampling is a difficult procedure that should be performed in experienced centers. Data from the SPAIN-ALDO registry have provided important information on the nationwide management of this pathology.

Primary aldosteronism and obstructive sleep apnea: A meta-analysis of prevalence and metabolic characteristics

BACKGROUND

Primary aldosteronism (PA) and obstructive sleep apnea (OSA) are both causes for resistant hypertension and contribute to adverse cardiovascular outcome. However, the association of these two disorders remains to be investigated. We conducted this meta-analysis to estimate the prevalence and metabolic characteristics of the coexistence of PA and OSA.

METHODS

The databases of MEDLINE, EMBASE and Cochrane Reviews were searched for studies investigating the prevalence or clinical characteristics of PA and OSA until Jan 2023. Single proportions of PA and OSA were meta-analyzed for pooled prevalence and 95% confidence intervals (CIs). Odds ratios (ORs) and 95% CIs were calculated for the comparison of the prevalence. Mean differences (MDs) and 95% CIs were calculated for comparisons of the characteristics between patients with both OSA and PA and control groups.

RESULTS

A total of 16 studies were included. The pooled prevalence of PA was 27% (95% CI = 24-29%) in all patients with OSA (n = 3498). The prevalence of PA in patients with OSA was significantly higher than that in the patients without OSA (OR = 2.03, 95% CI = 1.30, 3.16, p = 0.002). The pooled prevalence (95% CI) of OSA was 46% (39-54%) in patients with PA (n = 2335). Compared with the hypertensive patients without PA, the prevalence of OSA in the patients with PA was significantly higher (OR = 2.01, 95% CI = 1.37, 2.95, p < 0.001). Compared with the patients of control groups, the patients with both PA and OSA had higher blood pressure and body mass index (BMI).

CONCLUSION

Screening for the coexistence of PA and OSA was warranted.

Underdiagnosis of Primary Aldosteronism: A Review of Screening and Detection

A clinical condition may be missed due to its higher-than-recognized prevalence or inadequate diagnostic screening. Both factors apply to primary aldosteronism, which is woefully underdiagnosed as a cause of hypertension and end-organ damage. Screening tests should be strongly considered for diseases that pose significant morbidity or mortality if left untreated, that have a high prevalence, and that have treatments that lead to improvement or cure. In this review we present the evidence for each of these points. We outline studies that estimate the prevalence of primary aldosteronism in different at-risk populations and how its recognition has changed over time. We also evaluate myriad studies of screening rates for primary aldosteronism and what factors do and do not influence current screening practices. We discuss the ideal conditions for screening, measuring the aldosterone to renin ratio in different populations that use plasma renin activity or direct renin concentration, and the steps for diagnostic workup of primary aldosteronism. Finally, we conclude with potential strategies to implement higher rates of screening and diagnosis of this common, consequential, and treatable disease.

Primary Aldosteronism Prevalence - An Unfolding Story

Primary aldosteronism (PA) is characterized by dysregulated, renin-independent aldosterone excess. Long perceived as rare, PA has emerged as one of the most common causes of secondary hypertension. Failure to recognize and treat PA results in cardiovascular and renal complications, through processes mediated by both direct target tissue insults and indirectly, by hypertension. PA spans a continuum of dysregulated aldosterone secretion, which is typically recognized in late stages after treatment-resistant hypertension and cardiovascular and/or renal complications develop. Determining the precise disease burden remains challenging due to heterogeneity in testing, arbitrary thresholds, and populations studied. This review summarizes the reports on PA prevalence among the general population and in specific high-risk subgroups, highlighting the impact of rigid versus permissive criteria on PA prevalence perception.

Chronic intermittent hypoxia promotes glomerular hyperfiltration and potentiates hypoxia-evoked decreases in renal perfusion and PO2

Introduction: Sleep apnea (SA) is highly prevalent in patients with chronic kidney disease and may contribute to the development and/or progression of this condition. Previous studies suggest that dysregulation of renal hemodynamics and oxygen flux may play a key role in this process. The present study sought to determine how chronic intermittent hypoxia (CIH) associated with SA affects regulation of renal artery blood flow (RBF), renal microcirculatory perfusion (RP), glomerular filtration rate (GFR), and cortical and medullary tissue PO2 as well as expression of genes that could contribute to renal injury. We hypothesized that normoxic RBF and tissue PO2 would be reduced after CIH, but that GFR would be increased relative to baseline, and that RBF, RP, and tissue PO2 would be decreased to a greater extent in CIH vs. sham during exposure to intermittent asphyxia (IA, FiO2 0.10/FiCO2 0.03). Additionally, we hypothesized that gene programs promoting oxidative stress and fibrosis would be activated by CIH in renal tissue. Methods: All physiological variables were measured at baseline (FiO2 0.21) and during exposure to 10 episodes of IA (excluding GFR). Results: GFR was higher in CIH-conditioned vs. sham (p < 0.05), whereas normoxic RBF and renal tissue PO2 were significantly lower in CIH vs. sham (p < 0.05). Reductions in RBF, RP, and renal tissue PO2 during IA occurred in both groups but to a greater extent in CIH (p < 0.05). Pro-oxidative and pro-fibrotic gene programs were activated in renal tissue from CIH but not sham. Conclusion: CIH adversely affects renal hemodynamic regulation and oxygen flux during both normoxia and IA and results in changes in renal tissue gene expression.

Screening for Primary Aldosteronism Among Hypertensive Adults with Obstructive Sleep Apnea: A Retrospective Population-Based Study

BACKGROUND

Hypertension plus obstructive sleep apnea (OSA) is recommended in some guidelines as an indication to screen for primary aldosteronism (PA), yet prior data has brought the validity of this recommendation into question. Given this context, it remains unknown whether this screening recommendation is being implemented into clinical practice.

METHODS

We conducted a population-based retrospective cohort study of all adult Ontario (Canada) residents with hypertension plus OSA from 2009 to 2020 with follow-up through 2021 utilizing provincial health administrative data. We measured the proportion of individuals who underwent PA screening via the aldosterone-to-renin ratio by year. We further examined screening rates among patients with hypertension plus OSA by the presence of concurrent hypokalemia and resistant hypertension. Clinical predictors associated with screening were assessed via Cox regression modeling.

RESULTS

The study cohort included 53,130 adults with both hypertension and OSA, of which only 634 (1.2%) underwent PA screening. Among patients with hypertension, OSA, and hypokalemia, the proportion of eligible patients screened increased to 2.8%. Among patients ≥65 years with hypertension, OSA, and prescription of ≥4 antihypertensive medications, the proportion of eligible patients screened was 1.8%. Older age was associated with a decreased likelihood of screening while hypokalemia and subspecialty care with internal medicine, cardiology, endocrinology, or nephrology were associated with an increased likelihood of screening. No associations with screening were identified with sex, rural residence, cardiovascular disease, diabetes, or respirology subspecialty care.

CONCLUSIONS

The population-level uptake of the guideline recommendation to screen all patients with hypertension plus OSA for PA is exceedingly low.

Prevalence of primary aldosteronism in patients with concomitant hypertension and obstructive sleep apnea, baseline data of a cohort

Obstructive sleep apnea (OSA) and primary aldosteronism (PA) often coexist in hypertension, whereas whether hypertensive patients with OSA should be screened for PA is controversial and whether gender, age, obesity and OSA severity should be considered is unexplored. We explored cross-sectionally prevalence and associated factors of PA in co-existent hypertension and OSA by considering gender, age, obesity and OSA severity. OSA was defined as AHI ≥5 events/h. PA diagnosis was defined, based on the 2016 Endocrine Society Guideline. We included 3306 patients with hypertension (2564 with OSA). PA prevalence was significantly higher in hypertensives with OSA than in those without OSA (13.2 vs 10.0%, P = 0.018). In gender-specific analysis, PA prevalence was significantly higher in hypertensive men with OSA, compared to non-OSA ones (13.8 vs 7.7%, P = 0.001). In further analysis, PA prevalence was significantly higher in hypertensive men with OSA aged <45 years (12.7 vs 7.0%), 45-59 years (16.6 vs 8.5%), and with overweight and obesity (14.1 vs 7.1%) than did their counterparts (P < 0.05). For OSA severity, men participants showed increased PA prevalence from non to moderate OSA and a decrease in the severe OSA group (7.7 vs 12.9 vs 15.1 vs 13.7%, P = 0.008). Young and middle age, moderate-severe OSA, weight, and blood pressure showed a positive independent association with PA presence in logistic regression. In conclusion, PA is prevalent in co-existent hypertension and OSA, indicating the need for PA screening. Studies are needed for women, older and lean population due to the smaller samples in this study.

Influence and implications of the renin-angiotensin-aldosterone system in obstructive sleep apnea: An updated systematic review and meta-analysis

Obstructive sleep apnea is a chronic, sleep-related breathing disorder, which is an independent risk factor for cardiovascular disease. The renin-angiotensin-aldosterone system regulates salt and water homeostasis, blood pressure, and cardiovascular remodelling. Elevated aldosterone levels are associated with excess morbidity and mortality. We aimed to analyse the influence and implications of renin-angiotensin-aldosterone system derangement in individuals with and without obstructive sleep apnea. We pooled data from 20 relevant studies involving 2828 participants (1554 with obstructive sleep apnea, 1274 without obstructive sleep apnea). The study outcomes were the levels of renin-angiotensin-aldosterone system hormones, blood pressure and heart rate. Patients with obstructive sleep apnea had higher levels of plasma renin activity (pooled wmd+ 0.25 [95% confidence interval 0.04-0.46], p = 0.0219), plasma aldosterone (pooled wmd+ 30.79 [95% confidence interval 1.05-60.53], p = 0.0424), angiotensin II (pooled wmd+ 5.19 [95% confidence interval 3.11-7.27], p < 0.001), systolic (pooled wmd+ 5.87 [95% confidence interval 1.42-10.32], p = 0.0098) and diastolic (pooled wmd+ 3.40 [95% confidence interval 0.86-5.94], p = 0.0086) blood pressure, and heart rate (pooled wmd+ 3.83 [95% confidence interval 1.57-6.01], p = 0.0009) compared with those without obstructive sleep apnea. The elevation remained significant (except for renin levels) when studies involving patients with resistant hypertension were removed. Sub-group analysis demonstrated that levels of angiotensin II were significantly higher only among the Asian population with obstructive sleep apnea compared with those without obstructive sleep apnea. Body mass index accounted for less than 10% of the between-study variance in elevation of the renin-angiotensin-aldosterone system parameters. Patients with obstructive sleep apnea have higher levels of renin-angiotensin-aldosterone system hormones, blood pressure and heart rate compared with those without obstructive sleep apnea, which remains significant even among patients without resistant hypertension.

Implementation of a formal sleep center-based screening protocol for primary aldosteronism in patients with obstructive sleep apnea

BACKGROUND

There is a bidirectional association between primary aldosteronism and obstructive sleep apnea, with evidence suggesting that the treatment of primary aldosteronism can reduce obstructive sleep apnea severity. Current guidelines recommend screening for primary aldosteronism in patients with comorbid hypertension and obstructive sleep apnea, identifying potential candidates for treatment. However, emerging data suggest current screening practices are unsatisfactory. Moreover, data regarding the true incidence of primary aldosteronism among this population are limited. This study aimed to assess the primary aldosteronism screening rate among patients with obstructive sleep apnea and hypertension at our institution and estimate the prevalence of primary aldosteronism among this population.

METHODS

Sleep studies conducted at our institution between January and September 2021 were retrospectively reviewed. Adult patients with a sleep study diagnostic of obstructive sleep apnea (respiratory disturbance index ≥5) and a diagnosis of hypertension were included. Patient medical records were reviewed and laboratory data of those with biochemical screening for primary aldosteronism were assessed by an experienced endocrinologist. Screening rates were compared before and after initiation of a screening protocol in accordance with the 2016 Endocrine Society guidelines.

RESULTS

A total of 1,005 patients undergoing sleep studies were reviewed; 354 patients had comorbid obstructive sleep apnea and hypertension. Patients were predominantly male (67%), with a mean age of 58 years (standard deviation = 12.9) and mean body mass index of 34 (standard deviation = 8.1). The screening rate for primary aldosteronism among included patients was 19% (n = 67). The screening rate was significantly higher after initiation of a dedicated primary aldosteronism screening protocol (23% vs 12% prior; P = .01). Fourteen screens (21%) were positive for primary aldosteronism, whereas 45 (67%) were negative and 8 (12%) were indeterminate. Four had prior abdominal cross-sectional imaging, with 3 revealing an adrenal adenoma. Compared with patients without primary aldosteronism, patients with positive primary aldosteronism screens were more likely to have a history of hypokalemia (36% vs 4.4%; P = .002). The frequency of hyperlipidemia, diabetes mellitus, and left ventricular hypertrophy did not differ between patients with positive versus negative screens.

CONCLUSION

Current screening practices for primary aldosteronism among patients with comorbid obstructive sleep apnea and hypertension are suboptimal. Patients evaluated at sleep centers may represent an optimal population for screening, as the prevalence of primary aldosteronism among this cohort appears high.

Primary Aldosteronism: State-of-the-Art Review

We are witnessing a revolution in our understanding of primary aldosteronism (PA). In the past 2 decades, we have learned that PA is a highly prevalent syndrome that is largely attributable to pathogenic somatic mutations, that contributes to cardiovascular, metabolic, and kidney disease, and that when recognized, can be adequately treated with widely available mineralocorticoid receptor antagonists and/or surgical adrenalectomy. Unfortunately, PA is rarely diagnosed, or adequately treated, mainly because of a lack of awareness and education. Most clinicians still possess an outdated understanding of PA; from primary care physicians to hypertension specialists, there is an urgent need to redefine and reintroduce PA to clinicians with a modern and practical approach. In this state-of-the-art review, we provide readers with the most updated knowledge on the pathogenesis, prevalence, diagnosis, and treatment of PA. In particular, we underscore the public health importance of promptly recognizing and treating PA and provide pragmatic solutions to modify clinical practices to achieve this.

Who should be screened for primary aldosteronism? A comprehensive review of current evidence

Arterial hypertension is a major risk factor for cardiovascular disease. The prevalence of primary aldosteronism (PA) ranges from 5% to 10% in the general hypertensive population and is regarded as one of the most common causes of secondary hypertension. There are two major causes of PA: bilateral adrenal hyperplasia and aldosterone-producing adenoma. The diagnosis of PA comprises screening, confirmatory testing, and subtype differentiation. The Endocrine Society Practice Guidelines for the diagnosis and treatment of PA recommends screening of patients at an increased risk of PA. These categories include patients with stage 2 and 3 hypertension, drug-resistant hypertension, hypertensive with spontaneous or diuretic-induced hypokalemia, hypertension with adrenal incidentaloma, hypertensive with a family history of early onset hypertension or cerebrovascular accident at a young age, and all hypertensive first-degree relatives of patients with PA. Recently, several studies have linked PA with obstructive sleep apnea and atrial fibrillation unexplained by structural heart defects and/or other conditions known to cause the arrhythmia, which may be partly responsible for the higher rates of cardiovascular and cerebrovascular accidents in patients with PA. The aim of this review is to discuss which patients should be screened for PA, focusing not only on well-established guidelines but also on additional groups of patients with a potentially higher prevalence of PA, as has been reported in recent research.

High Prevalence of Autonomous Aldosterone Production in Hypertension: How to Identify and Treat It

PURPOSE OF REVIEW

Primary aldosteronism (PA) affects millions of individuals worldwide. When unrecognized, PA leads to cardiovascular and renal complications via mechanisms independent from those mediated by hypertension. In this review, we emphasize the importance of PA screening in at-risk populations, and we provide options for customized PA therapy, with consideration for a variety of clinical care settings.

RECENT FINDINGS

Compelling evidence puts PA at the forefront of secondary hypertension etiologies. Cardiovascular and renal damage likely begins in early stages of renin-independent aldosterone excess. PA must be considered not only in patients with resistant hypertension or hypokalemia, but also when hypertension is associated with obstructive sleep apnea or atrial fibrillation, or in those with early-onset hypertension. Screening with plasma aldosterone and renin is widely accessible, and targeted PA therapy can successfully circumvent the excess cardiorenal risk relative to equivalent primary hypertension. Identifying and treating PA in early stages provide opportunities for personalized hypertension therapy in a large number of patients. Additionally, early targeted therapy of PA is essential for pivoting the care of such patients from reactive to preventive of cardiovascular and renal morbidity and mortality.

Cerebro-Cardiovascular Risk, Target Organ Damage, and Treatment Outcomes in Primary Aldosteronism

Primary aldosteronism (PA) is the most common type of endocrine hypertension, and numerous experimental and clinical evidence have verified that prolonged exposure to excess aldosterone is responsible for an increased risk of cerebro-cardiovascular events and target organ damage (TOD) in patients with PA. Therefore, focusing on restoring the toxic effects of excess aldosterone on the target organs is very important to reduce cerebro-cardiovascular events. Current evidence convincingly demonstrates that both surgical and medical treatment strategies would benefit cerebro-cardiovascular outcomes and mortality in the long term. Understanding cerebro-cardiovascular risk in PA would help clinical doctors to achieve both early diagnosis and treatment. Therefore, in this review, we will summarize the cerebro-cardiovascular risk in PA, focusing on the TOD of aldosterone, including brain, heart, vascular system, renal, adipose tissues, diabetes, and obstructive sleep apnea (OSA). Furthermore, the various treatment outcomes of adrenalectomy and medical treatment for patients with PA will also be discussed. We hope this knowledge will help improve cerebro-cardiovascular prognosis and reduce the incidence and mortality of cerebro-cardiovascular events in patients with PA.

Primary Hyperaldosteronism: When to Suspect It and How to Confirm Its Diagnosis

The definition of primary hyperaldosteronism (PA) has shifted, as progress has been made in understanding the disease. PA can be produced by unilateral or bilateral cortical adrenal hyperproduction of aldosterone, due to hyperplasia, aldosterone-secreting cell clusters, aldosterone-producing macro or micro adenoma/s, and combinations of the above, or by an aldosterone-producing carcinoma. PA is a highly prevalent disease, affecting close to 10% of the hypertensive population. However, PA is clearly underdiagnosed. The purpose of this review is to address current knowledge of PA’s clinical manifestations, as well as current methods of diagnosis. PA is associated with a higher cardiovascular morbidity and mortality than essential hypertension with similar blood pressure control. Young hypertensive patients, those with a first-degree relative with PA or ictus, and/or those with apnea/hypopnea syndrome, moderate/severe/resistant hypertension, adrenal incidentaloma, and/or hypokalemia should be screened for PA. PA can induce atrial fibrillation (AF), and those patients should also be screened for PA. We propose the use of the Captopril challenge test (CCT), oral salt loading, or intravenous salt loading for PA diagnosis, given their availability in the majority of hospital centers. CCT could be first-line, since it is safe and easy to perform.

Association of objective and subjective parameters of obstructive sleep apnea with plasma aldosterone concentration in 2,066 hypertensive and 25,368 general population

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) severity has been suggested in aldosterone elevation in resistant hypertension, whereas it is undetermined in the rest population. We explored the association of OSA parameters with plasma aldosterone concentration (PAC) in participants with and without hypertension.

METHODS

We enrolled clinically hypertensive patients with polysomnography and PAC data under no interfering agents, compared (log) PAC, and assessed the linearity of log PAC by tertiles (T1/2/3) of sleep parameters and their association using linear regression by gender and age. We enrolled participants with and without hypertension who had No-SAS scale and PAC data from the community and duplicated the observations from clinical setting considering age, gender, and presence of hypertension.

RESULTS

Of the 2,066 clinical patients with hypertension (1,546 with OSA), men participants (n=1,412), log apnea-hypopnea index (p=0.043), apnea index (AI, p=0.010), and lowest oxygen saturation (LSaO₂, p=0.013) showed significant linearity with log PAC. Log AI (B=0.04, 95%CI: 0.01,0.07, p=0.022) and log LSaO₂ (B=-0.39, 95%CI: -0.78,-0.01, p=0.044) showed significant positive and negative linear associations with log PAC in regression. In community dwellers, 6,417 participants with untreated hypertension (2,642 with OSA) and 18,951 normotensive participants (3,000 with OSA) were included. Of the men participants with and without hypertension, the OSA group showed significantly higher (log) PAC than did their counterparts, and log No-SAS score showed positive association with log PAC (hypertension: B=0.072, 95%CI: 0.002,0.142, p=0.043; normotension: B=0.103, 95%CI: 0.067,0.139, p<0.001) in linear regression analysis, which were consistent in all age groups.

CONCLUSIONS

OSA parameters were positively associated with PAC in normotensive and hypertensive participants, indicating that OSA may increase circulating aldosterone, especially in men.

Primary aldosteronism and obstructive sleep apnea: What do we know thus far?

Both primary aldosteronism and obstructive sleep apnea are well-known causes of hypertension and contribute to increased cardiovascular morbidity and mortality independently. However, the relationship between these two entities remains unclear, with studies demonstrating contradictory results. This review aims to collate and put into perspective current available research regarding the association between primary aldosteronism and obstructive sleep apnea. The relationship between these two entities, clinical characteristics, clinical implications, outcomes of treatment, potential causal links and mechanisms are hereby presented.

Screening for Primary Aldosteronism is Underutilized in Patients with Obstructive Sleep Apnea

BACKGROUND

Resistant hypertension is common in patients with primary aldosteronism and in those with obstructive sleep apnea. Primary aldosteronism treatment improves sleep apnea. Despite Endocrine Society guidelines' inclusion of sleep apnea and hypertension co-diagnosis as a primary aldosteronism screening indication, the state of screening implementation is unknown.

METHODS

All hypertensive adult patients with obstructive sleep apnea (n = 4751) at one institution between 2012 and 2020 were compared with a control cohort without sleep apnea (n = 117,815). We compared the association of primary aldosteronism diagnoses, risk factors, and screening between both groups. Patients were considered to have screening if they had a primary aldosteronism diagnosis or serum aldosterone or plasma renin activity evaluation.

RESULTS

Obstructive sleep apnea patients were predominantly men and had higher body mass index. On multivariable analysis, hypertensive sleep apnea patients had higher odds of drug-resistant hypertension (odds ratio [OR] 2.70; P < .001) and hypokalemia (OR 1.26; P < .001) independent of body mass index, sex, and number of antihypertensive medications. Overall, sleep apnea patients were more likely to be screened for primary aldosteronism (OR 1.45; P < .001); however, few patients underwent screening whether they had sleep apnea or not (pre-guideline publication 7.8% vs 4.6%; post-guidelines 3.6% vs 4.6%; P < .01). Screening among eligible sleep apnea patients remained low prior to and after guideline publication (4.4% vs 3.4%).

CONCLUSIONS

Obstructive sleep apnea is associated with primary aldosteronism risk factors without formal diagnosis, suggesting screening underutilization and underdiagnosis. Strategies are needed to increase screening adherence, as patients may benefit from treatment of concomitant primary aldosteronism to reduce sleep apnea severity and its associated cardiopulmonary morbidity.

Screening for primary aldosteronism in the hypertensive obstructive sleep apnea population is cost-saving

BACKGROUND

Guidelines recommend screening for primary aldosteronism in patients diagnosed with hypertension and obstructive sleep apnea. Recent studies have shown that adherence to these recommendations is extremely low. It has been suggested that cost is a barrier to implementation. No analysis has been done to rigorously evaluate the cost-effectiveness of widespread implementation of these guidelines.

METHODS

We constructed a decision-analytic model to evaluate screening of the hypertensive obstructive sleep apnea population for primary aldosteronism as per guideline recommendations in comparison with current rates of screening. Probabilities, utility values, and costs were identified in the literature. Threshold and sensitivity analyses assessed robustness of the model. Costs were represented in 2020 US dollars and health outcomes in quality-adjusted life-years. The model assumed a societal perspective with a lifetime time horizon.

RESULTS

Screening per guideline recommendations had an expected cost of $47,016 and 35.27 quality-adjusted life-years. Continuing at current rates of screening had an expected cost of $48,350 and 34.86 quality-adjusted life-years. Screening was dominant, as it was both less costly and more effective. These results were robust to sensitivity analysis of disease prevalence, test sensitivity, patient age, and expected outcome of medical or surgical treatment of primary aldosteronism. The screening strategy remained cost-effective even if screening were conservatively presumed to identify only 3% of new primary aldosteronism cases.

CONCLUSIONS

For patients with hypertension and obstructive sleep apnea, rigorous screening for primary aldosteronism is cost-saving due to cardiovascular risk averted. Cost should not be a barrier to improving primary aldosteronism screening adherence.

Prospective Screening for Primary Aldosteronism in Patients With Suspected Obstructive Sleep Apnea

[Figure: see text].

Adrenal vein sampling: technique and protocol, a systematic review

Primary aldosteronism is the leading cause of secondary hypertension worldwide. Its deleterious effects outstrip those due to blood pressure elevation alone. An essential part of the work-up of a patient with primary aldosteronism is determining if aldosterone production is unilateral or bilateral. With the former, surgery offers a potential cure and better overall outcomes. Adrenal vein sampling is considered the most reliable method to determine whether production is unilateral or bilateral. Sampling may be non-diagnostic when the vein cannot be properly cannulated. But with proper knowledge and experience as well as the utilization of certain techniques, procedure success can be high. Multiple protocols exist; their rationale and drawbacks are reviewed here. This article will give the reader an overview of techniques for improving procedural success as well as background, rationale and evidence to guide one in choosing the appropriate procedural and interpretation protocol.

Primary aldosteronism is highly prevalent in patients with hypertension and moderate to severe obstructive sleep apnea

STUDY OBJECTIVES

It has been suggested that there might be a pathophysiological link and overlap between primary aldosteronism (PA) and obstructive sleep apnea (OSA). Therefore, in a prospective study, we evaluated the frequency of PA in hypertensive patients suspected of having OSA.

METHODS

We included 207 consecutive hypertensive patients (mean age 53.2 ± 12.1 years, 133 M, 74 F) referred for polysomnography on the basis of one or more of the following clinical features: typical OSA symptoms, resistant or difficult-to-treat hypertension, diabetes, or cardiovascular disease. PA was diagnosed based on thew saline infusion test.

RESULTS

Moderate-to-severe OSA was diagnosed in 94 patients (45.4% of the whole group). PA was diagnosed in 20 patients with OSA (21.3%) compared with 9 patients in the group without OSA (8.0%; P = .006). PA was also frequent in patients in whom symptoms of OSA were a sole indication for PA screening (15.4%) and in patients with and without resistant hypertension (24.5% and 17.8%, respectively). Most patients with PA and OSA were diagnosed with bilateral adrenal hyperplasia (18 patients, 90%). There were no major differences in clinical characteristics between patients with OSA with PA and those without PA. In multivariate models, moderate-to-severe OSA predicted the presence of PA (odds ratio 2.89, P = .018).

CONCLUSIONS

Patients with clinically important moderate-to-severe OSA are characterized by a relatively high frequency of PA. Our results support the recommendations to screen patients with moderate-to-severe OSA for PA, regardless of the presence of other indications for PA screening.

Obstructive Sleep Apnea-Induced Neurogenic Nocturnal Hypertension: A Potential Role of Renal Denervation?

There is a bidirectional, causal relationship between obstructive sleep apnea (OSA) and hypertension. OSA-related hypertension is characterized by high rates of masked hypertension, elevated nighttime blood pressure, a nondipper pattern of nocturnal hypertension, and abnormal blood pressure variability. Hypoxia/hypercapnia-related sympathetic activation is a key pathophysiological mechanism linking the 2 conditions. Intermittent hypoxia also stimulates the renin-angiotensin-aldosterone system to promote hypertension development. The negative and additive cardiovascular effects of OSA and hypertension highlight the importance of effectively managing these conditions, especially when they coexist in the same patient. Continuous positive airway pressure is the gold standard therapy for OSA but its effects on blood pressure are relatively modest. Furthermore, this treatment did not reduce the cardiovascular event rate in nonsleepy patients with OSA in randomized controlled trials. Antihypertensive agents targeting sympathetic pathways or the renin-angiotensin-aldosterone system have theoretical potential in comorbid hypertension and OSA, but current evidence is limited and combination strategies are often required in drug resistant or refractory patients. The key role of sympathetic nervous system activation in the development of hypertension in OSA suggests potential for catheter-based renal sympathetic denervation. Although long-term, randomized controlled trials are needed, available data indicate sustained and relevant reductions in blood pressure in patients with hypertension and OSA after renal denervation, with the potential to also improve respiratory parameters. The combination of lifestyle interventions, optimal pharmacological therapy, continuous positive airway pressure therapy, and perhaps also renal denervation might improve cardiovascular risk in patients with OSA.

The Role of Aldosterone in OSA and OSA-Related Hypertension

Obstructive sleep apnea (OSA) is regarded as an independent risk factor for hypertension. The possible mechanism includes oxidative stress, endothelial injury, sympathetic excitement, renin-angiotensin-aldosterone system activation, etc. Clinical studies have found that there is a high coexistence of OSA and primary aldosteronism in patients with hypertension and that elevated aldosterone levels are independently associated with OSA severity in resistant hypertension. The underlying mechanism is that aldosterone excess can exacerbate OSA through increasing overnight fluid shift and affecting the mass and function of upper airway muscles during the sleep period. Thus, a bidirectional influence between OSA and aldosterone exists and contributes to hypertension in OSA patients, especially resistant hypertension.

Primary Aldosteronism: Cardiovascular Risk, Diagnosis, and Management

Primary aldosteronism remains a leading cause of secondary hypertension, and its diagnosis and management continue to pose a challenge for clinicians. In this article, we review the diagnosis of primary aldosteronism along with its cardiovascular manifestations. Treatment is described depending on the diagnostic outcome, focusing on medical management with mineralocorticoid receptor antagonists and unilateral adrenalectomy. Although screening and diagnosing hyperaldosteronism follows well-known algorithms, in practice, physicians may find difficulty establishing the best course of action due to complexity in testing and confirming laterality of aldosterone production by the adrenals. Recognizing and treating primary aldosteronism requires a multidisciplinary approach with primary care physicians, cardiologists, endocrinologists, and radiologists working collaboratively.

Hyperaldosteronism: How Current Concepts Are Transforming the Diagnostic and Therapeutic Paradigm

Nearly seven decades have elapsed since the clinical and biochemical features of primary hyperaldosteronism (PA) were described by Conn. PA is now widely recognized as the most common form of secondary hypertension. PA has a strong correlation with cardiovascular disease and failure to recognize and/or properly diagnose this condition has profound health consequences. With proper identification and management, PA has the potential to be surgically cured in a proportion of affected individuals. The diagnostic pursuit for PA is not a simplistic endeavor, particularly because an enhanced understanding of the disease process is continually redefining the diagnostic and treatment algorithm. These new concepts have emerged in all areas of this clinical condition, including identification, diagnosis, and treatment. Here, we review the recent advances in this field and summarize the effect these advances have on both diagnostic and therapeutic modalities.

Genetics, prevalence, screening and confirmation of primary aldosteronism: a position statement and consensus of the Working Group on Endocrine Hypertension of The European Society of Hypertension

: Autonomous aldosterone overproduction represents the underlying condition of 5-10% of patients with arterial hypertension and carries a significant burden of mortality and morbidity. The diagnostic algorithm for primary aldosteronism is sequentially based on hormonal tests (screening and confirmation tests), followed by lateralization studies (adrenal CT scanning and adrenal venous sampling) to distinguish between unilateral and bilateral disease. Despite the recommendations of the Endocrine Society guideline, primary aldosteronism is largely underdiagnosed and undertreated with high between-centre heterogeneity. Experts from the European Society of Hypertension have critically reviewed the available literature and prepared a consensus document constituting two articles to summarize current knowledge on the epidemiology, diagnosis, treatment, and complications of primary aldosteronism.

In the Refractory Hypertension “Labyrinth”. Focus on Primary Hyperaldosteronism

Primary hyperaldosteronism is an existence of a functional autonomous source with increased aldosterone production (full or partial) in relation to the renin-angiotensin system. Increased production of aldosterone by the adrenal cortex is the most common form of a secondary hypertension despite the low attention of internists to the problem. The success of a treatment and a prognosis of these patients depend on correct choice of screening (aldosterone/renin ratio) and clarifying diagnostic methods. There are clear algorithms for conducting these tests in accordance with Russian and International recommendations in the respective groups of patients. The purpose of this case report is to demonstrate the long way to diagnosis of primary hyperaldosteronism in a young patient with refractory hypertension, right adrenal adenoma, and clinical (convulsions, weakness) and laboratory signs of hypokalemia. It should not only have made the diagnosis easy, but it could have also absolutely justified the surgical tactics. Unfortunately, the final verification of the disease by carrying out a saline test was accomplished 13 years after the debut of hypertension and 10 years after the primary visualization of the adrenal adenoma.

Sleep disturbances: one of the culprits of obesity-related cardiovascular risk?

Growing evidence suggested that Sleep Disorders (SD) could increase the risk of developing obesity and could contribute to worsen obesity-related cardiovascular risk. Further, obesity per se has been reported to blunt sleep homeostasis. This happens through several mechanisms. First of all, the excessive adipose tissue at neck and chest levels could represent a mechanical obstacle to breathe. Moreover, the visceral adipose tissue is known to release cytokines contributing to low-grade chronic inflammation that could impair the circadian rhythm. Also, nutrition plays an important role in sleep homeostasis. High fat and/or high carbohydrate diets are known to have a negative impact on both sleep quality and duration. In addition, obesity predisposes to a condition called "obstructive sleep apnea" that has a detrimental effect on sleep. SD could increase the risk and/or could contribute to worsen cardiovascular risk usually associated with obesity. The chronic low grade inflammation associated with obesity has been reported to increase the risk of developing hypertension, type 2 diabetes and dyslipidemia. In turn, improving quality of sleep has been reported to improve the management of these cardiovascular risk factors. Thus, the aim of this manuscript is to provide evidence on the association of obesity and SD and on how they could contribute to the risk of developing cardiovascular risk factors such as hypertension, dyslipidemia and type 2 diabetes in obesity.

Primary Aldosteronism and Obstructive Sleep Apnea: Casual Association or Pathophysiological Link?

The coexistence of aldosterone oversecretion and obstructive sleep apnea is frequently observed, especially in patients with resistant hypertension, obesity, and metabolic syndrome. Since aldosterone excess and sleep apnea are both independently associated with an increased risk of cardiovascular disease, to investigate whether their coexistence might be attributed to common predisposing conditions, such as metabolic disorders, or to an actual pathophysiological interconnection appears of great importance. Fluid overload and metabolic abnormalities relating to aldosterone oversecretion may be implicated in obstructive sleep apnea development. Nocturnal intermittent hypoxia may in turn exacerbate renin-angiotensin-aldosterone system activity, thus leading to hyperaldosteronism. Furthermore, fat tissue excess and adipocyte secretory products might predispose to both sleep apnea and aldosterone oversecretion in subjects with obesity. Consistent with these evidences, obstructive sleep apnea frequently affects patients with primary aldosteronism. Conversely, whether primary aldosteronism is more prevalent in individuals affected by obstructive sleep apnea compared to the general population remains controversial.

Recent advances in understanding and managing resistant/refractory hypertension

The management of resistant hypertension presents several challenges in everyday clinical practice. During the past few years, several studies have been performed to identify efficient and safe pharmacological and non-pharmacological options for the management of such patients. The Spironolactone versus placebo, bisoprolol, and doxazosin to determine the optimal treatment for drug-resistant hypertension (PATHWAY-2) trial demonstrated significant benefits with the use of spinorolactone as a fourth-line drug for the treatment of resistant hypertension over doxazosin and bisoprolol. In addition, recent data support that spironolactone may demonstrate superiority over central acting drugs in such patients, as well. Based on the European guidelines, spironolactone is recommended as the fourth-line drug option, followed by amiloride, other diuretics, doxazosin, bisoprolol or clonidine.  Among several device-based approaches, renal sympathetic denervation had fallen into hibernation after the disappointing results of the Renal Denervation in Patients With Uncontrolled Hypertension (SYMPLICITY HTN) 3 trial. However, the technique re-emerged at the epicenter of the clinical and research interest after the favorable results of three sham-controlled studies, which facilitated novel catheters and techniques to perform the denervation. Significant results of iliac anastomosis on blood pressure levels have also been demonstrated. Nevertheless, the technique-related adverse events resulted in withdrawal of this interventional approach. Last, the sympatholytic properties of the carotid baroreceptor activation therapy were associated with significant blood pressure reductions in patients with resistant hypertension, which need to be verified in larger controlled trials. Currently device-based approaches are recommended only in the setting of clinical trials until more safety and efficacy data become available.

Prevalence, diagnosis and outcomes of treatment for primary aldosteronism

Primary aldosteronism (PA) is the most common potentially curable form of hypertension. The overproduction of aldosterone leads to an increased risk of cardiovascular and cerebrovascular events as well as adverse effects to the heart and kidney and psychological disorders. PA is mainly caused by unilateral aldosterone excess due to an aldosterone-producing adenoma or bilateral excess due to bilateral adrenocortical hyperplasia. The diagnostic work-up of PA comprises three steps: screening, confirmatory testing and differentiation of unilateral surgically-correctable forms from medically treated bilateral PA. These specific treatments can mitigate or reverse the increased risks associated with PA. Herein we summarise the prevalence, outcomes and current and future clinical approaches for the diagnosis of primary aldosteronism.

A Guide to Management of Sleepiness in ESKD

Daytime sleepiness, also known as hypersomnolence, is common among patients receiving maintenance dialysis and following successful kidney transplantation. Sleepiness may be secondary to medical comorbid conditions, medication side effect, insufficient sleep syndrome, and sleep-disordered breathing or the result of a primary central disorder of hypersomnolence, such as narcolepsy. Unrecognized and untreated sleep disorders are associated with substantial morbidity and mortality among patients with end-stage kidney disease. Effective management of hypersomnolence can improve quality of life in patients with kidney disease. This review focuses on the principal causes of sleepiness in patients with end-stage kidney disease. Awareness of these disorders by treating nephrologists is crucial. This review provides a systematic approach to guide providers through the recognition, early diagnosis, and treatment of hypersomnolence, which is commonly encountered in this patient population. Areas of future research are also suggested.

Associations between primary aldosteronism and diabetes, poor bone health, and sleep apnea-what do we know so far?

Primary aldosteronism (PA), the most common cause of secondary hypertension, is a well-recognized condition that can lead to cardiovascular and renal complications. PA is frequently left undiagnosed and untreated, leading to aldosterone-specific morbidity and mortality. In this review we highlight the evidence linking PA with other conditions such as (i) diabetes mellitus, (ii) obstructive sleep apnea, and (iii) bone health, along with clinical implications and proposed underlying mechanisms.

Primary Aldosteronism and Obstructive Sleep Apnea: A Cross-Sectional Multi-Ethnic Study

The association between primary aldosteronism (PA) and obstructive sleep apnea (OSA) has been a matter of debate. 2016 Endocrine Society guideline recommends screening for PA all hypertensive patients with OSA. We designed a multicenter, multiethnic, cross-sectional study to evaluate the prevalence of PA in patients with OSA and the prevalence of OSA in unselected patients with PA. Two hundred and three patients with OSA (102 whites and 101 Chinese) were screened for PA, and 207 patients with PA (104 whites, 100 Chinese, and 3 of African descent) were screened for OSA by cardiorespiratory polygraphy. Eighteen patients with OSA (8.9%) had PA (11.8% of white and 5.9% of Chinese ethnicity). In patients without other indications for PA screening, the prevalence of PA dropped to 1.5%. The prevalence of OSA in patients with PA was 67.6%, consistent in both white and Chinese patients. A correlation between aldosterone levels and apnea/hypopnea index was observed in white patients with PA (R²=0.225, P=0.016) but not in Chinese patients. Multinomial logistic regression confirmed a significant and independent association between plasma aldosterone levels and moderate to severe OSA diagnosis in white patients (odds ratio, 1.002; P=0.002). In conclusion, aldosterone levels may contribute to the severity of OSA in white patients with hyperaldosteronism, but patients with OSA are not at high risk of PA. Results of the present study challenge the current recommendation of the Endocrine Society guideline that all patients with OSA should be screened for PA, irrespective of the grade of hypertension.

Adherence to consensus guidelines for screening of primary aldosteronism in an urban healthcare system

BACKGROUND

Primary aldosteronism is a common cause of secondary hypertension. Treatment with adrenalectomy or mineralocorticoid receptor-blockers can prevent long-term adverse outcomes. This study aimed to determine primary aldosteronism screening rats in patients with hypertension in an underserved urban healthcare system.

METHODS

We reviewed records of outpatient adults in an urban healthcare system from 2013 to 2017. Chart review along with International Statistical Classification of Diseases, 9th and 10th editions, diagnosis codes were used to identify patients meeting inclusion criteria for screening according to the 2016 Endocrine Society guidelines. The corresponding aldosterone, plasma renin activity, and 24-hour urine aldosterone values were identified. Multivariate logistic regression was performed to determine positive predictors of screening.

RESULTS

Of 15,511 hypertensive patients seen, 6,809 (43.8%) met criteria for screening. Blacks were the most common racial group, and Medicare and Medicaid were the most frequent insurers. The aldosterone-to-renin ratio level was checked in 86 (1.3%) patients; 22 (25.6%) had an aldosterone-to-renin ratio >20. Of the 77 patients with hypertension and incidentaloma, 14 (18.2%) had an aldosterone-to-renin ratio checked. Additional positive predictors for being screened were hypertension and hypokalemia and sustained hypertension.

CONCLUSION

Screening rates for primary aldosteronism in an underserved population are low. Proper identification of primary aldosteronism in those at risk could help ameliorate long-term effects of disease.

Endocrine responses during CPAP withdrawal in obstructive sleep apnoea: data from two randomised controlled trials

The aim of this investigation was to elucidate the effect of CPAP withdrawal on neurometabolic and cardiometabolic markers in patients with obstructive sleep apnoea. We evaluated 70 patients (mean age 61±10 years, 82% men) treated with CPAP in two 2-week, parallel, randomised controlled trials. CPAP withdrawal resulted in elevated 3,4-dihydroxyphenylglycol, norepinephrine and cortisol after 2 weeks of CPAP withdrawal; however, no statistically significant changes of the renin-angiotensin-aldosterone system (RAAS) determinants were documented. In summary, CPAP withdrawal may be more prominently linked to short-term increases in sympathetic activation than hypothalamic-pituitary-adrenal axis or RAAS activation. ClinicalTrials.gov Identifier: NCT02493673 and NCT02050425.

Chronic kidney disease in patients with obstructive sleep apnea. A narrative review

Prevalence of both chronic kidney disease (CKD) and obstructive sleep apnea (OSA) is continuously increasing. Moreover, the prevalence of OSA increases as kidney function declines and is higher among patients with end-stage renal disease (ESRD). In addition, OSA is recognized as a potential nontraditional risk factor for development and progression of CKD. Continuous positive airway pressure (CPAP) plays a pivotal role in the management of OSA, eliminating patients' symptoms and improving their quality of life. Recent studies suggested that CPAP treatment may have beneficial effects on kidney function among patients with OSA. This narrative review summarizes the existing knowledge on the association between CKD and OSA, with emphasis on the epidemiology, the pathophysiology of the development of CKD in OSA and vice versa, as well as the effect of CPAP on renal function.

The Association of Obstructive Sleep Apnea and Hypertension

Obstructive sleep apnea (OSA) is a condition characterized by recurrent episodes of partial or complete upper airway obstruction during sleep. Hypertension (HTN) is defined by the presence of a chronic elevation of systemic arterial pressure above a certain threshold value (≥140 mm Hg systolic or ≥90 mm Hg diastolic). On the surface, OSA and HTN appear very different from one another. Despite this, they share several common risk factors including obesity, male gender, and advancing age. In 2003, the Seventh Joint National Committee (JNC VII) recognized OSA as a secondary cause of HTN. As physicians, our goal is to understand the OSA-HTN association better through academic study regarding its epidemiology, its pathophysiology, and its treatment. 

Clinical characteristics of snoring patients with primary aldosteronism and obstructive sleep apnea-hypopnea syndrome

The 2016 guideline on the work-up of primary aldosteronism recommended that patients with obstructive sleep apnea–hypopnea syndrome (OSAS) be screened. This study aimed to identify the clinical characteristics of snoring patients with primary aldosteronism (PA) complicated by OSAS. Sixty-eight self-reported or witnessed snoring patients and 609 non-snoring patients diagnosed with PA between 2010 and 2015 were recruited in this retrospective study. Compared to non-snoring patients, snoring patients had significantly (P < 0.05) higher body mass index (BMI), diastolic blood pressure (DBP), and serum and urinary sodium, as well as lower estimated glomerular filtration rate (eGFR). Moreover, snoring patients exhibited significantly (P < 0.01) higher plasma renin activity levels and lower plasma aldosterone levels and aldosterone-to-renin activity ratios (ARRs) than patients with PA alone. When age, sex, duration of hypertension, and BMI were matched between groups, snoring patients still showed significantly (P < 0.05) higher plasma renin activity, serum and urinary sodium, and lower ARR and eGFR than those in the PA-only group. All 68 snoring patients underwent polysomnography, with 7 having mild (apnea–hypopnea index (AHI) ≥ 5 and <15), 21 moderate (AHI ≥ 15 and <30), and 40 severe (AHI ≥ 30) OSAS. The BMI of patients with OSAS was negatively correlated with the lowest SaO₂ (r = −0.318, P = 0.018) but not with the AHI. In conclusion, snoring patients with PA tend to have increased BMI and DBP, as well as decreased eGFR and ARR. Snoring patients with PA had higher prevalence of moderate-to-severe OSAS.

Resistant Hypertension: Detection, Evaluation, and Management: A Scientific Statement From the American Heart Association

Resistant hypertension (RH) is defined as above-goal elevated blood pressure (BP) in a patient despite the concurrent use of 3 antihypertensive drug classes, commonly including a long-acting calcium channel blocker, a blocker of the renin-angiotensin system (angiotensin-converting enzyme inhibitor or angiotensin receptor blocker), and a diuretic. The antihypertensive drugs should be administered at maximum or maximally tolerated daily doses. RH also includes patients whose BP achieves target values on ≥4 antihypertensive medications. The diagnosis of RH requires assurance of antihypertensive medication adherence and exclusion of the "white-coat effect" (office BP above goal but out-of-office BP at or below target). The importance of RH is underscored by the associated risk of adverse outcomes compared with non-RH. This article is an updated American Heart Association scientific statement on the detection, evaluation, and management of RH. Once antihypertensive medication adherence is confirmed and out-of-office BP recordings exclude a white-coat effect, evaluation includes identification of contributing lifestyle issues, detection of drugs interfering with antihypertensive medication effectiveness, screening for secondary hypertension, and assessment of target organ damage. Management of RH includes maximization of lifestyle interventions, use of long-acting thiazide-like diuretics (chlorthalidone or indapamide), addition of a mineralocorticoid receptor antagonist (spironolactone or eplerenone), and, if BP remains elevated, stepwise addition of antihypertensive drugs with complementary mechanisms of action to lower BP. If BP remains uncontrolled, referral to a hypertension specialist is advised.

Systemic hypertension in obstructive sleep apnea

There is consistent epidemiological evidence that sleep disordered breathing and systemic arterial hypertension are deeply associated, being linked through a bidirectional complex interaction among multiple mechanisms including autonomic nervous system alterations, inflammation, hormonal and hemodynamic components, sleep alterations. However there are several unanswered questions not only from a pathophysiological perspective, but also regarding the effects of obstructive sleep apnea (OSA) treatment on arterial blood pressure values. At present, while many studies have supported the possibility to obtain at least a small blood pressure reduction with OSA treatment, in particular in hypertensive patients, large trials have not clearly confirmed a significant anti-hypertensive effect, nor a beneficial effect of this intervention on cardiovascular endpoints including cardiovascular mortality. Aim of the present review article is to address the relationship between OSA and hypertension in the light of the latest evidence in the field. Moreover we will discuss research topics which need to be investigated in the future, in order to better clarify still pending issues with the aim of obtaining an early diagnosis, a more suitable phenotyping including comorbidities, and better strategies to improve patients' compliance and adherence to treatment.

Primary aldosteronism in the primary care setting

PURPOSE OF REVIEW

The aim of the present manuscript is to provide an overview of the most updated studies on the prevalence of primary aldosteronism in primary care and to compare these figures with the actual rate of diagnosis in clinical practice and with the prevalence of primary aldosteronism in specific subgroup of patients.

RECENT FINDINGS

Over the last 20 years the clinical spectrum of low renin hypertension and primary aldosteronism has changed dramatically. Once considered only in the presence of severe hypertension and hypokalemia, it is now well known that primary aldosteronism is not uncommon even in patients with mild forms of hypertension and/or normokalemia. Moreover, recent evidence points toward a large proportion of normotensive study participants as being affected by subclinical primary aldosteronism, which represents a strong risk factor for incident hypertension. Moreover, primary aldosteronism patients are exposed to an increased risk of cardio and cerebrovascular events and metabolic comorbidities compared with patients affected by essential hypertension. Disappointingly, primary aldosteronism remains a largely underdiagnosed and undertreated disorder.

SUMMARY

These recent findings further highlight the importance of widening the spectrum of patients who should be screened for primary aldosteronism, to reduce the cardiovascular risk associated with this medical condition.

A Review of the Literature Regarding Sleep and Cardiometabolic Disease in African Descent Populations

In the twenty-first century, African descent populations on both the continent of Africa and throughout the world are experiencing a high rate of both sleep disturbances and cardiometabolic diseases. The most common sleep disturbances are reduced sleep duration, insomnia, disordered circadian rhythm, and obstructive sleep apnea. Cardiometabolic diseases include hypertension, coronary artery disease, diabetes, hyperlipidemia, and the metabolic syndrome. This review seeks to call attention to new insights regarding the impact of sleep disturbance on cardiometabolic risk factors and outcomes and then apply these concepts to African descent populations, a relatively understudied population. Initial data suggest disparities in sleep quality may have an important role in current and emerging patterns of cardiometabolic disease for African descent populations both in the United States and abroad.

CLINICALTRIALSGOV IDENTIFIER

Not applicable.