Computational fluid dynamics study in children with obstructive sleep apnea.

OBJECTIVES: This study aims to identify characteristics in image-based computational fluid dynamics (CFD) in children with obstructive sleep apnea (OSA). DESIGN: Diagnostic study. SETTING: Hospital-based cohort. PARTICIPANTS: Children with symptoms suggestive of OSA were recruited and underwent polysomnography. MAIN OUTCOME MEASURES: Three-dimensional models of computational fluid dynamics were derived from cone-beam computed tomography. RESULTS: A total of 68 children participated in the study (44 boys; mean age: 7.8 years), including 34 participants having moderate-to-severe OSA (apnea-hypopnea index [AHI] greater than 5 events/h), and 34 age, gender, and body mass index percentile matched participants having primary snoring (AHI less than 1). Children with moderate-to-severe OSA had a significantly higher total airway pressure (166.3 vs. 39.1 Pa, p = .009), total airway resistance (9851 vs. 2060 Newton-metre, p = .004) and velocity at a minimal cross-sectional area (65.7 vs. 8.8 metre per second, p = .017) than those with primary snoring. The optimal cut-off points for moderate-to-severe OSA were 46.2 Pa in the total airway pressure (area under the curve [AUC] = 73.2%), 2373 Newton-metre in the total airway resistance (AUC = 72.5%) and 12.6 metres per second in the velocity at a minimal cross-sectional area (AUC = 70.5%). The conditional logistic regression model revealed that total airway pressure, total airway resistance and velocity at minimal cross-sectional area were significantly associated with an increased risk of moderate-to-severe OSA. CONCLUSIONS: This study demonstrates that CFD could be a useful tool for evaluating upper airway patency in children with OSA.

Association Between Obstructive Sleep Apnea, Its Treatment, and Alzheimer's Disease: Systematic Mini-Review.

Obstructive sleep apnea (OSA) and Alzheimer's disease (AD) are common in the elderly population. Obstructive sleep apnea that may cause significant changes in the cerebrospinal fluid ß-amyloid and T-tau and/or P-tau protein levels is often identified as a risk factor for development of AD. Although the underlying mechanisms of AD are still not fully understood, a hypothesis associating OSA with AD has been already proposed. In this systematic mini-review, we first discuss the recent findings supporting the association of OSA with an increased risk of AD and then provide evidence suggesting the positive effect of OSA treatment on a reduced risk of AD.