Resistant hypertension, obstructive sleep apnoea and aldosterone

Abstract

Obstructive sleep apnoea (OSA) and hypertension commonly coexist. Observational studies indicate that untreated OSA is strongly associated with an increased risk of prevalent hypertension, whereas prospective studies of normotensive cohorts suggest that OSA may increase the risk of incident hypertension. Randomized evaluations of continuous positive airway pressure (CPAP) indicate an overall modest effect on blood pressure (BP). Determining why OSA is so strongly linked to having hypertension in cross-sectional studies, but yet CPAP therapy has limited BP benefit needs further exploration. The CPAP studies do, however, indicate a wide variation in the BP effects of CPAP, with some patients manifesting a large antihypertensive benefit such that a meaningful BP effect can be anticipated in some individuals. OSA is particularly common in patients with resistant hypertension (RHTN). The reason for this high prevalence of OSA is not fully explained, but data suggest that it may be related to the high occurrence of hyperaldosteronism in patients with RHTN. In patients with RHTN, it has been shown that aldosterone levels correlate with severity of OSA and that blockade of aldosterone reduces the severity of OSA. Overall, these findings are consistent with aldosterone excess contributing to worsening of underlying OSA. We hypothesize that aldosterone excess worsens OSA by promoting accumulation of fluid within the neck, which then contributes to increased upper airway resistance.

Perioperative management of the severely obese patient: a selective pathophysiological review

“…Aldosterone levels are elevated in obesity with MetS 23 and even more so in patients with obstructive sleep apnea (OSA), where levels correlate with the number of hypoxic episodes. 24 Aldosterone contributes to the development of LV fibrosis and decreases nitric oxide availability and endothelial function. 25 On this basis, aldosterone antagonists may be a beneficial addition to conventional renin-angiotensin-system inhibition.…”

The quality and characteristics of sleep of hypertensive patients

“…Another disease with high morbidity in the population is the Obstructive Sleep Apnea Syndrome (OSAS), and it is estimated that approximately 40% of hypertensive patients and 80% of those with resistant hypertension have OSAS (8)(9) and about 55% individuals with OSAS have hypertension (10) .…”

Nocturnal Blood Pressure Is Reduced by a Mandibular Advancement Device for Sleep Apnea in Women: Findings From Secondary Analyses of a Randomized Trial

“…High aldosterone secretion increases the retention of sodium and water in the kidneys and is related to the severity of obstructive sleep apnea and blood pressure level 24, 26, 27. Hypertension in women is more sensitive to sodium intake than in men 27.…”