Is there an association between cognitive impairment and urinary adrenaline, norepinephrine, gamma-aminobutyric acid, and taurine levels in children with obstructive sleep apnea?: A case control study.

Background: Children with obstructive sleep apnea (OSA) can develop cognitive impairments. Urinary adrenaline (EPI), norepinephrine (NE) and gamma-aminobutyric acid (GABA) are elevated, and taurine is decreased in children with OSA. The purpose of this study was to investigate the above-mentioned neurotransmitter levels in children with and without OSA, and explore their association with OSA-related cognitive impairments.

Methods: Children underwent overnight polysomnography (PSG) for habitual snoring or mouth breathing in the pediatric sleep center from February 2023 to February 2024, as well as a group of healthy controls were enrolled in this study. Pediatric Quality of Life Inventory (PedsQL) and Child Behavior Checklist (CBCL) were used to evaluate the cognitive function of these children. Morning urine samples were collected to measure the urinary neurotransmitter levels.

Results: This study recruited 74 children with OSA, 30 children with primary snoring (PS) and 16 healthy controls. In the comparison of PedsQL scores, social function (85(75, 100)), school function (65.88 ± 18.52), and total scores (74.15 ± 12.74) of OSA group were significantly lower than that of non-OSA group (P < 0.05); OSA group also exhibited increased withdrawn (1 (0, 2)) and attention problems (2 (1, 5)) scores in CBCL than non-OSA group (P < 0.05). A total of 39 cases in the OSA group (PedsQL total score below 77.42) were considered to have mild cognitive impairment (MCI), who had higher urinary EPI (190.68 ± 38.77 ng/ml) and lower taurine (432.20 ± 53.52 ng/ml) levels than both PS and OSA without MCI groups (P < 0.001). Logistic regression analysis showed that high levels of urinary NE (OR = 1.027, 95%CI: 1.002 ~ 1.052) and low levels of taurine (OR = 0.982, 95%CI: 0.969 ~ 0.995) are significantly associated with cognitive impairment in children with OSA, and their combination has a larger area under the curve (0.695) for prediction, with a sensitivity of 64.1% and specificity of 68.6% (P = 0.004).

Conclusions: Children with OSA presented impaired cognitive functions such as school, social function deficits and attention problems. Measuring urinary EPI and taurine levels may contribute to the prediction of OSA-related cognitive impairments.