OBSTRUCTIVE SLEEP APNEA AND PRIMARY ALDOSTERONISM: A MULTICENTER CROSS-SECTIONAL STUDY

Abstract

Objective: 2016 Endocrine Society guideline recommends screening for primary aldosteronism (PA) all patients with hypertension and obstructive sleep apnea (OSA), despite evidences supporting this recommendation are limited. We designed a multi-ethnic, multicentre, cross-sectional study to assess the prevalence of PA in patients with OSA and the prevalence of OSA in unselected patients with PA. Design and method: 203 patients with OSA (101 Chinese and 102 of Caucasian ethnicity) were screened for PA, followed by confirmatory test and subtyping diagnosis in case of confirmed PA. 207 patients with PA (104 Caucasians, 100 Chinese and 3 of African descent) were tested by cardio-respiratory polygraphy for OSA diagnosis. Results: The prevalence of PA in patients with OSA was 8.9% (11.8% in Caucasian and 5.9% in Chinese patients). Among patients without other indications for PA screening beyond OSA diagnosis, the prevalence of PA was very low (1.5%). The prevalence of OSA in patients with PA was 67.6% (64.4% in Caucasians, 70.0% in Chinese ethnicity). We observed a significant correlation between serum aldosterone levels and apnea/hypopnea index in Caucasian patients with PA (R2 = 0.360, p = 0.013), but not in the Chinese patients with PA. In the Caucasian group with PA, multinomial logistic regression confirmed a significant association between aldosterone levels and moderate-severe OSA (OR 1.002, p = 0.002), but no association was present in the Chinese group. Conclusions: Patients with OSA do not display a higher risk of PA, challenging the Endocrine Society guideline recommendation of screening all patients with OSA for PA, irrespective of the grade of hypertension. However, OSA is a frequent condition in patients with PA and aldosterone level can contribute to OSA severity in patients with PA of Caucasian ethnicity.