Obstructive Sleep Apnea and Endothelial Function in School-Aged Nonobese Children

Abstract

Background-Obstructive sleep apnea (OSA) in children is associated with cardiovascular morbidity such as systemic and pulmonary hypertension. However, it remains unclear whether endothelial dysfunction occurs in pediatric OSA and whether it is reversible on effective treatment of OSA. Methods and Results-Consecutive nonobese children (aged 6 to 11 years) who were diagnosed with OSA after overnight polysomnography and control children matched on the basis of age, gender, ethnicity, and body mass index underwent blood draw the next morning for soluble CD40 ligand, asymmetric dimethylarginine (ADMA), and nitrotyrosine levels, as well as 2 iterations of 60-second cuff-occlusion tests for assessment of endothelial function. These tests were repeated 4 to 6 months after adenotonsillectomy. OSA children showed blunted reperfusion kinetics after release of occlusion, which completely normalized in 20 of 26 patients after adenotonsillectomy. All 6 children in whom no improvements occurred had a strong family history of cardiovascular disease (versus 2 of the remaining 20 patients; PϽ0.04). Plasma nitrotyrosine and ADMA levels were similar in OSA and control children; however, soluble CD40 ligand levels were higher in OSA children and were reduced after treatment, particularly in those with normalized hyperemic responses. Conclusions-Postocclusive hyperemia is consistently blunted in children with OSA, and such altered endothelial function is reversible 4 to 6 months after treatment, particularly if a family history of cardiovascular disease is not present. Although no evidence for either nitric oxide-dependent oxidative/nitrosative stress or for the increased presence of the circulating nitric oxide synthase inhibitor ADMA was found in children with OSA, soluble CD40 ligand levels were increased in OSA and reflected the changes in endothelial function after treatment.

A Different Clinical Type of OSAS: REM-Related OSAS

“…A striking finding is that in non-obese children with OSAS, REM-related OSAS is more frequently detected (19). In studies performed on children with OSAS, the development of morbidities as metabolic dysfunction, hypertension, vascular endothelial dysfunction, systemic inflammation, and increased oxidative stress have been demonstrated (30)(31)(32)(33). Observations gathered from children display their importance in the definition of REM-related events in adults.…”

Obstructive sleep apnea and cardiovascular risk in children

“…Подобные изменения были выявлены у детей, при-чем отмечалось улучшение функции эндотелия на фоне лечения апноэ сна [59]. Показано, что ожи-рение и наличие обструктивного апноэ сна в препу-бертатном возрасте оказывают сочетанное негатив-ное воздействие на состояние эндотелия сосудов [60].…”

Current Treatment of Selected Pediatric Sleep Disorders

“…Defining the outcomes of importance in evaluating treatments in children with OSA is itself worth considering. Studies have identified and reported post-therapy AHI and/or oxygen saturation and other respiratory measures, sleep EEG analysis such as sleep stages, spindles, arousals, and spectral analysis, various neurocognitive and/or behavioral measures, parental and teacher report of improvement or satisfaction, academic performance, and more recently serologic markers [5][6][7][8] such as C-Reactive Protein, and other physiological tests [7,9] as evidence of treatment effect. Interestingly, these outcomes do not necessarily show symmetry at baseline or in response to intervention ; for example, in children treated by adenotonsillectomy, hyperactivity, inattention, cognitive function, and other neurobehavioral morbidities all tended to be improved a year after treatment, but little correlation has been seen between some of these variables and polysomnographic measures before or after surgery, though esophageal pressure monitoring as a more sensitive measure of breathing abnormalities may offer some promise in this regard [10,11].…”