Sleep-related Breathing Disorder Is an Independent Risk Factor for Systemic Hypertension

Abstract

The exact influence of sleep-related breathing disorder (SRBD) on blood pressure control remains unknown. We investigated the influence of different degrees of SRBD on daytime blood pressure and its association to documented hypertension by examining 1,190 consecutive patients referred for diagnosis of SRBD. The protocol includes clinical interview, physical examination, office blood pressure measurement, cholesterol, and blood gas analysis. Unattended home monitoring of nocturnal breathing was performed for assessment of SRBD activity (respiratory disturbance index [RDI]). RDI was independently and linearly associated with systolic blood pressure (unstandardized coefficient [B] = 0.07 +/- 0.03, p = 0.03), diastolic blood pressure (B = 0.07 +/- 0.02, p = 0 < 0.001), and heart rate (B = 0.10 +/- 0.02, p < 0.001) at rest. The relative risk for hypertension (blood pressure >/= 160/95 mm Hg) increased with SRBD severity (odds ratio [OR], 4.15 for RDI >/= 40 versus < 5 [95% CI, 2.7 to 6.5]). This relative risk was also elevated in younger (</= 50 yr) compared with older patients (> 50 yr) (OR, 7.15 versus 2.70 for RDI >/= 40 versus < 5). These cross-sectional clinical data suggest a relationship between SRBD severity and systolic blood pressure, diastolic blood pressure, and heart rate after control for confounders such as body mass index (BMI), age, alcohol/nicotine consumption, cholesterol level, and daytime PO(2) and PCO(2). SRBD is an independent risk factor for systemic hypertension with an increased likelihood in subjects </= 50 yr of age.

Modificação do padrão respiratório melhora o controle cardiovascular na hipertensão essencial

“…Some scientific evidence suggests that changes in breathing control may also be regarded as a risk factor associated with lifestyle in hypertensive patients 20 .…”

“…According to Brooks et al 25 , these changes in blood pressure control occur both during sleep and daytime, thereby suggesting a causal role of sleep breathing disorders in the development and maintenance of hypertension. Other than that, epidemiological studies show that sleep-disordered breathing is highly prevalent among hypertensive patients 26,27 , and also that 50 to 80% of the patients who experience such changes are hypertensive 20 . In this regard, the causal relationship of respiratory disorders might become confusing or disappear when age, obesity prevalence, smoking status, and alcohol consumption are taken into account in hypertensive patients.…”

Therapy with nCPAP: incomplete elimination of Sleep Related Breathing Disorder

“…In this context it may be speculated that remaining RDI under CPAP is an important determinant for the extent of a preventive effect. Two large cross-sectional studies have demonstrated an independent dose-response relationship between RDI and systolic/diastolic blood pressure [23,24]. As for cardiovascular morbidity and mortality in OSA, there is increasing evidence, that nCPAP may have beneficial effects [7, 25±27].…”

Dynamics of Heart Rate and Sleep Stages in Normals and Patients with Sleep Apnea

“…Even if the arousal remains below the level of consciousness, the temporal sequence of sleep stages is severely disrupted and the restorative function of sleep is destroyed. Sleep apnea is regarded as an independent risk factor for systemic hypertension (Grote et al, 1999).…”