Abstract
IMPORTANCE: The incidence of obstructive sleep apnea syndrome (OSAS) in children has increased year by year recently. Blood pressure research of OSAS children can help understand the occurrence of OSAS related complications. Early detection and intervention of blood pressure changes in children with OSAS can reduce the incidence of cardiovascular disease in later adulthood. OBJECTIVE: To investigate the differences in blood pressure among different groups of snoring children and different sleep stages. METHODS: Habitually snoring children (snoring frequency of ≥ 3 nights per week) aged 3 to 11 years were recruited from Beijing Children's Hospital from 1 January 2017 to 30 June 2018. All children underwent polysomnography, and their blood pressure was monitored and calculated by the pulse transit time. The children were divided into those with primary snoring (PS), mild OSAS, and moderate to severe OSAS according to their obstructive apnea-hypopnea index (OAHI). RESULTS: In total, 140 children were included. Ninety-seven had PS, 24 had mild OSAS, and 19 had moderate to severe OSAS. There were no differences in age, sex, or body mass index z-score among the groups. Statistically significant differences were found in the OAHI, oxygen desaturation index 3%, respiratory arousal index, and lowest oxygen saturation among the three groups. Children with moderate to severe OSAS had higher systolic and diastolic blood pressure than those with mild OSAS and PS (P < 0.001). In all children, systolic and diastolic blood pressure was higher in the rapid eye movement (REM) sleep stage than in the non-REM sleep stage (P < 0.05). INTERPRETATION: Children with moderate to severe OSAS had higher blood pressure than those with PS and mild OSAS in all sleep stages. Blood pressure in the REM sleep stage was higher than that in other sleep stages in all groups of children.