Treatment of Primary Aldosteronism Reduces the Probability of Obstructive Sleep Apnea

Sleep-related breathing disorder in a Japanese occupational population and its association with hypertension-stratified analysis by obesity status

Sleep-related breathing disorder (SRBD) causes hypertension, and obesity has been highly associated with SRBD, which has become a serious health problem in young and middle-aged Japanese males. However, the relation between SRBD and hypertension considering the effects of obesity remains unknown. In this cross-sectional study, we examined the relationship between SRBD and hypertension, with consideration for the effects of obesity, in Japanese occupational population. Using 3% oxygen desaturation index (3%ODI) obtained by simplified polysomnography (PSG), participants were classified into low (0 ≤ 3%ODI < 5), medium (5 ≤ 3%ODI < 15), and high (15 ≤ 3%ODI) 3%ODI groups. We excluded employees who had not undergone medical examination with simplified PSG in the same year from 2012 to 2018. Logistic regression analysis was performed to calculate odds ratios for having hypertension according to 3%ODI levels. In total, 2532 employees were included. Among them, 25% and 4% were categorized into the medium and high 3%ODI groups, respectively. The odds ratio for hypertension increased significantly with higher 3%ODI levels after adjustment for age, sex, alcohol drinking status and smoking status (p for trend < 0.0001). However, further adjustment for obesity status (body mass index ≥ 25 kg/m2) attenuated the associations. When we performed the stratified analysis by obesity status, the odds ratio for hypertension increased significantly with higher 3%ODI only for non-obese individuals, with significant interaction (p for interaction = 0.014). Higher 3%ODI was significantly associated with higher prevalence of hypertension especially in non-obese participants, suggesting the importance of vigilance for the presence of SRBD even in non-obese individuals. We investigated the association between SRBD and hypertension considering the effects of obesity, which would suggest the need to keep in mind the presence of SRBD even in non-obese individuals.

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.

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.

Impact of Primary Aldosteronism in Resistant Hypertension

PURPOSE OF REVIEW

In this narrative review, we aim to summarize the latest data on the association between primary aldosteronism and resistant hypertension, as well as to emphasize the necessity for screening for primary aldosteronism all patients with resistant hypertension.

RECENT FINDINGS

Epidemiological data suggests that up to one out of five patients with resistant hypertension suffer from primary aldosteronism. Patients with primary aldosteronism have increased incidence of renal disease, diabetes mellitus, atrial fibrillation, and obstructive sleep apnea, as well as they are characterized by an extended target organ damage and increased cardiovascular morbidity and mortality. Specific treatments for primary hyperaldosteronism (adrenalectomy and mineralocorticoid receptor antagonists) have significant impact on blood pressure, can reverse target organ damage, and mitigate cardiovascular risk. All patients with resistant hypertension should be evaluated for primary aldosteronism. Patients diagnosed with the disease may further undergo lateralization with adrenal vein sampling in order to receive the optimal therapeutic option which results in significant improvements in quality of life and cardiovascular profile.

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.

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

Primary aldosteronism (PA) is a common cause of secondary hypertension caused by excessive and inappropriate secretion of the hormone aldosterone from one or both adrenal glands. The prevalence of PA ranges from 10% in the general hypertensive population to 20% in resistant hypertension, yet only a small fraction of patients is diagnosed. Disease and symptom recognition, screening in indicated populations, multidisciplinary communication, and appropriate imaging and biochemical workup can identify patients who might benefit from effective and targeted treatment modalities. Effective treatments available include both surgical and medical approaches, usually dependent on the subtype of PA present. Our collective understanding of the pathophysiology of PA is expanded by recent developments in molecular biology and genetics, including understanding the specific somatic and germline mutations involved in pathogenesis. We review the pathophysiology, diagnostic workup, and treatment considerations for this disease process.

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.