Hypertension in obstructive sleep apnea: the hidden role of renin-angiotensin-aldosterone system dysregulation

Hypertension commonly co-exists with obstructive sleep apnea (OSA). However, the role of renin-angiotensin-aldosterone system (RAAS) in the development of hypertension in OSA patients remains poorly defined, with inconclusive evidence regarding the activation of the RAAS in these patients. Herein, we aimed to evaluate the RAAS profile in OSA patients and to elucidate the influence of RAAS on hypertension in these individuals.

In this observational study, patients referred from health clinics aged 18 years and older, with obesity, defined as body mass index greater than 27.5 kg/m², and confirmed OSA were recruited if they met study criteria. Anthropometric data were collected, and blood sampled for plasma aldosterone concentration (PAC) and plasma renin concentration (PRC). Treatment intensity was assessed using the therapeutic intensity score (TIS). The RAAS components were compared between the OSA patients, healthy controls, and patients with confirmed primary aldosteronism.

A total of 204 patients who fulfilled the study criteria were recruited, of which 160 had hypertension. Patients with hypertensive OSA demonstrated higher PAC with no significant difference in PRC compared to normotensive OSA; and higher PAC and ARR with lower PRC compared to healthy controls. PAC was positively correlated with TIS (β = 0.281, p < 0.001), systolic blood pressure (β = 0.156, p = 0.049), and hypertension duration (β = 0.168, p = 0.011), while negatively correlated with hypertension diagnosis (β = - 0.170, p = 0.024).

This is the first study from Southeast Asia evaluating the impact of RAAS on hypertension severity in OSA patients. Findings suggest that hypertensive individuals with OSA exhibit greater RAAS dysregulation, highlighting the role of aldosterone in the development of hypertension and its severity in OSA. This also underscores the need for targeted management strategies particularly in tropical regions with a rising prevalence of metabolic disorders.