Factors related to pediatric obstructive sleep apnea–hypopnea syndrome in children with attention deficit hyperactivity disorder in different age groups

This study aimed to retrospectively investigate the factors related to pediatric obstructive sleep apnea–hypopnea syndrome (OSAHS) with attention deficit hyperactivity disorder (ADHD) in children younger than 6 years and those older than 6 years. A total of 437 children who were hospitalized due to OSAHS between January 2014 and December 2014 were retrospectively reviewed. The children were further divided into OSAHS group and OSAHS + ADHD group. The general characteristics, OSA-18 quality of life, intention-hyperactivity score, and polysomnographic parameters (apnea–hypopnea index and the lowest oxygen saturation) were collected and compared between groups. There were 298 boys and 139 girls with the male to female ratio of 2.14:1. ADHD was found in 146 children including 105 boys and 41 girls with the male to female ratio of 2.56:1. Of these children, 31.62% and 35.46% had concomitant ADHD in children aged 4 to 5 years and those aged 6 to 11 years, respectively. In children aged 4 to 5 years, the incidence of allergic rhinitis was significantly higher (P = .016) and the adenoid hypertrophy was more severe (P = .001) in those with concomitant ADHD. In children aged 6 to 11 years, the tonsil hypertrophy was more severe in those with concomitant ADHD (P = .019). In children with concomitant ADHD, OSA-18 score was higher than in those with OSAHS alone (P < .001). Higher frequency of respiratory events (P < .001) and more severe hypoxia (P < .001) were found in children with concomitant ADHD than in those with OSAHS alone. As high as 30% of OSAHS children have concomitant ADHD, and the incidence of ADHD in OSAHS children is increasing over age. Boys are more likely to develop OSAHS and incidence of ADHD in OSAHS boys is higher than in OSAHS girls. In addition, risk factors of ADHD also vary between age groups. The ADHD is related to the severity of allergic rhinitis and adenoid hypertrophy in children aged 4 to 5 years, and to the severity of tonsil hypertrophy in children aged 6 to 11 years. Hypoxia may be an important factor causing ADHD. OSAHS should be treated as early as possible to reduce the incidence of ADHD in children.