Influence of obesity on nocturnal oxygen saturation in young children.
Obesity is increasing worldwide and it is accompanied by major health effects. In adults and school-aged children, obesity is associated with decreased respiratory function, which may lead to disturbed sleeping and subsequently difficulties in concentration and behavioural disorders. The evidence for the association between obesity and decreased respiratory function in younger children is scarce. To explore the association between body weight and nocturnal respiratory function in young children, 1 to 3 years old, nocturnal pulse oximetry was performed at home. Children with tonsillar hypertrophy were excluded. Percentage of time with oxygen saturation (SpO(2)) <95 % was measured and its association with body mass index (BMI) for age z scores was analysed. Pulse oximetric data of 51 children, including 18 children with a BMI for age above +2 standard deviations, were obtained for this study. Linear regression analysis, correction for gender and parental smoking, showed a positive association between the natural logarithm of SpO(2) <95 % and BMI for age z score [regression coefficient (β) 0.19, 95 % confidence interval 0.00-0.39]. In young children, higher body weight is associated with a decrease in nocturnal oxygen saturation.