Objectives: Determination of the impact of obstructive sleep apnea (OSA) on the cognitive function (CF) and serum tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and 1β levels in children aged 5-12 years and the effect of OSA management on these variables.

Patients & Methods: 224 patients were evaluated using the Pediatric Sleep Questionnaire, the NEPSY score for CF and Polysomnography (PSG) to grade OSA severity according to the Apnea/hypopnea index (AHI). Patients with adenotonsillar hypertrophy grade >2 will undergo the appropriate surgical intervention. Overweight or obese patients with mild or moderate OSAS will undergo 6-m trial of lifestyle intervention (LSI). Blood samples were obtained for ELISA estimation of cytokines' levels. At end of 6-m follow-up, all variables were re-evaluated

All children aged 5-12 years who attended the outpatient clinics of Otorhinolaryngology and/or Pediatrics with complaints suggestive of OSAS were eligible for evaluation for exclusion and inclusion criteria according to the conditions of the Local Ethical Committee which approved the study protocol by number.

Evaluation Tools

1. Evaluation of body mass index (BMI): BMI was calculated according to Bray as weight (kg) divided by the square height (m2) and was interpreted according to the International Obesity Task Force (IOTF) BMI cut-offs according to the percentile of BMI adjusted for age and gender.

2. Pediatric Sleep Questionnaire (PSQ) using the sleep-related breathing disorders scale which consists of 3 domains including 22 items with three responses to each item Yes (=1), No (=0), and don't know = missed answer.

3. Neurocognitive Assessments using the NEPSY II score which is designed to assess six domains (Appendix 2), each domain was expressed as scaled scores with lower scores indicating cognitive dysfunction.

4. Otorhinolaryngologic assessment variables:

   • Assessment of the volume of the palatine tonsils using Brodsky grading scale Adenoid size was assessed by X-Ray soft tissue nasopharynx lateral view and graded according to. Assessment of the tongue position within the oral cavity to evaluate the extent of obstruction of the oral cavity by the tongue using the modified Mallampati method.
   • Polysomnography (PSG) was performed according to guidelines of the American Academy of Sleep Medicine (AASM) for the scoring of sleep and associated events. The hypopnea index (HI) indicated the number of hypopneas per hour of sleep and the Apnea/hypopnea index (AHI) is the summation of apnea and hypopnea indices.

5. Laboratory investigation: Venous blood samples (5 ml) were collected for ELISA estimation of serum levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and 1β.

Diagnosis and grading of OSAS

1. Diagnosis of OSAS:

   Pediatric OSAS was diagnosed according to guidelines of the American Academy of Sleep Medicine (21) depending on both the clinical findings and the polysomnographic criteria for diagnosis.

2. OSAS severity grading OSAS severity was graded according to the apnea-hypopnea index (AHI) into mild if AHI was 1-4.9, moderate if AHI 5-9.9, or severe if AHI > 10 and if AHI was >30 OSAS is very severe.

Inclusion Criteria:

• Children in age range of 5-12 years with mild-to-severe OSAS, free of exclusion criteria were enrolled in the study.

Exclusion Criteria:

• The presence of craniofacial anomalies
• neurological disorders
• very severe OSAS
• OSAS complicated by complex comorbidities
• residual OSAS following adenotonsillectomy (AT), hypothyroidism, or refusal of the suggested therapeutic plans.
• children who failed or were unable to undergo the cognitive function evaluation and those whose parents refused to undergo polysomnography were also excluded from the study.