Activity-Adjusted 24-Hour Ambulatory Blood Pressure and Cardiac Remodeling in Children with Sleep Disordered Breathing

Abstract

Abstract-Questions remain as to whether pediatric sleep disordered breathing increases the risk for elevated blood pressure and blood pressure-dependent cardiac remodeling. We tested the hypothesis that activity-adjusted morning blood pressure surge, blood pressure load, and diurnal and nocturnal blood pressure are significantly higher in children with sleep disordered breathing than in healthy controls and that these blood pressure parameters relate to left ventricular remodeling. 24-hour ambulatory blood pressure parameters were compared between groups. The associations between blood pressure and left ventricular relative wall thickness and mass were measured. 140 children met the inclusion criteria. In children with apnea hypopnea index Ͻ5 per hour, a significant difference from controls was the morning blood surge. Significant increases in blood pressure surge, blood pressure load, and in 24-hour ambulatory blood pressure were evident in those whom the apnea hypopnea index exceeded 5 per hour. Sleep disordered breathing and body mass index had similar effect on blood pressure parameters except for nocturnal diastolic blood pressure, where sleep disordered breathing had a significantly greater effect than body mass index. Diurnal and nocturnal systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure predicted the changes in left ventricular relative wall thickness. Therefore, sleep disordered breathing in children who are otherwise healthy is independently associated with an increase in morning blood pressure surge, blood pressure load, and 24-hour ambulatory blood pressure. The association between left ventricular remodeling and 24-hour blood pressure highlights the role of sleep disordered breathing in increasing cardiovascular morbidity. Key Words: sleep apnea Ⅲ children Ⅲ ambulatory blood pressure Ⅲ blood pressure surge Ⅲ blood pressure load Ⅲ cardiac remodeling Ⅲ hypertrophy T he association between sleep disordered breathing (SDB) and cardiovascular morbidity in adults has become an important consideration in the management of patients with SDB. Results from numerous cross-sectional and prospective studies of blood pressure (BP) control in adults support the concept that hypertension is an intermediate end point between SDB and cardiovascular disease. 1,2 Further support of this concept is derived from studies linking SDB to atherosclerotic pathways. [3][4][5][6] These studies provide insight into the mechanisms of vascular injury secondary to SDB. Although the impact of duration of this disorder on the development of risk factors for cardiovascular disease is difficult to estimate, morbidity secondary to SDB seems to manifest gradually, often taking decades. As such, with the exception of isolated cases of heart failure, children with SDB rarely show evidence of cardiovascular disease. Thus far, studies addressing whether children with SDB acquire risk factors for the early development of cardiovascular disease are inconclusive.Findings from several pediatric studies suggest ...

Sleep Apnea and Cardiovascular Disease

“…In these otherwise healthy children, an AHI Ͼ5 was associated with an increase in morning BP surge, heightened BP load (percentage of BP measurements exceeding the 95th percentile), and higher 24-hour BP. 385 It is unlikely that mild OSA in children will lead to significant cardiac dysfunction in the pediatric age range. However, it is not known whether mild OSA during early childhood predisposes to vascular injury and/or BP dysregulation during adolescence and adulthood.…”

“…In otherwise healthy children, those with more severe SDB (AHI Ͼ5) had higher activity-adjusted ambulatory BP and echocardiographic evidence of increased left ventricular wall thickness. 385 …”

Nocturnal enuresis is associated with moderate-to-severe obstructive sleep apnea in children with snoring

“…Furthermore, the potential interaction between NE and female gender regarding the association with obstructive AHI >5 episodes/hour was explored. Obstructive AHI >5 episodes/hour corresponds to moderate-to-severe OSA as proposed by Dayyat et al (10) and it is related to elevated systolic and diastolic blood pressure, increased risk of development of respiratory complications and persistent OSA following adenotonsillectomy as well as low likelihood of spontaneous OSA resolution without treatment interventions (11)(12)(13)(14).…”

Acute and Chronic Effects of Sleep Duration on Blood Pressure

“…Obesity is a well-established risk factor for OSA, 16,17 which has been demonstrated to lead to elevated BP. [18][19][20][21] Obesity itself is also a wellknown risk factor of elevated BP. 22 In the current study, we used more stringent criteria to minimize the confounding effects of obesity and OSA so as to focus on the independent relationship between sleep duration and BP.…”