[Characteristics of obstructive sleep apnea syndrome in patients with Down's syndrome]

Obstructive Sleep Apnea-Hypopnea Syndrome in Children Is Not Associated With Obesity

OBJECTIVE

The prevalence of obstructive sleep apnea-hypopnea syndrome (OSAHS) in the general pediatric population ranges from 1% to 3%. However, its prevalence in an unselected population of obese children is unknown. We studied the association between obesity and OSAHS in children diagnosed with the syndrome in a cohort of boys and girls (age range, 2-14 years) referred to the pediatric respiratory medicine outpatient clinic at our hospital for suspected apnea, snoring, or both over the past 5 years.

PATIENTS AND METHODS

The medical history of each patient was recorded and all patients underwent a physical examination, chest and nasal cavities radiography, and 8-channel respiratory polygraphy during sleep. The following variables were evaluated: sex, reason for consultation, source of referral, findings during upper airway examination, age, weight z-score (reflecting how much a finding differs from the mean and in what direction in a normally distributed sample), height z-score, body mass index (BMI) z-score, number of apneas, number of hypopneas, apnea index, hypopnea index, apnea-hypopnea index (AHI), oxygen saturation (mean and minimum) measured by pulse oximetry, number of snores, and snore index.

RESULTS

Of the 400 patients studied, 242 (60.5%) were male and 158 (39.5%) female. The mean age was 4.95 years. OSAHS (AHI> or =3) was diagnosed in 298 cases (74.5%) and these patients were then studied to determine the relation between OSAHS and obesity. The anthropometric distribution (expressed as mean [SD]) was as follows: weight z-score, 0.37 (1.31); height z-score, 0.23 (1.19); BMI, 17.063 kg/m(2) (2.51); and BMI z-score, 0.39 (1.36). The respiratory polygraph during sleep recorded an AHI of 6.56 (7.56).

CONCLUSIONS

No differences were observed between the height z-score, weight z-score, BMI z-score, age, and AHI. No association between obesity and OSAHS was found in this series. However, studies of larger, unselected populations are needed to determine if obesity is a risk factor for OSAHS in children.

[Obstructive sleep apnea-hypopnea syndrome]

We analyzed a cohort of 400 patients referred from the otorhinolaryngology department (40.05 %), primary care (PC) (36.52 %), and the pediatric pulmonary unit (17.63 %). The children were referred for clinical suspicion of apneas in 191 (47.87 %), snoring and apneas in 101 (25 %), and snoring in 87 (21.80 %). Adenotonsillar hypertrophy was found in 211 patients (52.75 %), tonsillar hypertrophy in 87 (21.75 %), and adenoid hypertrophy in 73 (18.25 %). All patients underwent respiratory polygraphy (RP) during sleep. Obstructive sleep apnea-hypopnea syndrome (OSAHS) was diagnosed in 298 patients (74.5 %). OSAHS was mild in 96 patients (24 %), moderate in 148 (37 %), and severe in 54 (13.5 %). The results of RP expressed in means plus standard deviation were as follows: number of apneas 21.38 (24.47), number of hypopneas 19.81 (20.74), apnea-hypopnea index per hour (AHI/h) 5.29 (7.10), mean oxygen saturation 94.60 (11.80), minimal saturation 83.14 (13.45), number of snores 98.27 (254.55), and snoring index per hour 5.68 (6.5). Significant differences were found between oxygen saturation and AHI/h per hour. No differences were found among age, mean oxygen saturation, area of residence, reason for consulting, and AHI/h. Adenotonsillectomy was performed in 289 patients (72.25 %) of the initial cohort. In conclusion, OSAHS in childhood is frequent. RP during sleep aids diagnosis. The main cause of OSAHS in children is adenotonsillar hypertrophy.