Obstructive sleep related breathing disorders and cardiometabolic risk factors - A Portuguese birth cohort

Background: Pediatric obstructive sleep related breathing disorders (SRBD) are an important under-diagnosed health problem with associated cardiometabolic comorbidities, demonstrated with polysomnographic studies in selected samples. Our main goal was to assess the prevalence of SRBD in a population -based cohort and to analyze its association with cardiometabolic risk factors, in general and by sex. Methods: Pediatric Sleep Questionnaire (PSQ) was applied to parents of 7 -years -old children evaluated in the birth cohort, Generation XXI. Sex, anthropometrics, blood pressure (BP), lipid profile, glucose, insulin, HOMA-IR, and high -sensitivity C-reactive protein were compared among children with/without SRBD, using Chi -square, Mann-Whitney tests and logistic regression models. Results: A total of 1931 children (51.2 % boys) were included; 17.5 % were overweight and 15.7 % obese. The prevalence of SRBD was 13.4 %, more frequent among boys (15.7 % vs.10.9 %, p = 0.002) and in overweight/ obese children (22.0 % vs.13.6 % vs.11.3 % in obese, overweight and normal weight group, respectively, p < 0.001). Children with SRBD had higher systolic BP (107 +/- 8 vs.105 +/- 9 mmHg; p = 0.001) and lower HDLcholesterol levels (54 +/- 11 vs.56 +/- 11 mg/dL; p = 0.04) than children without SRBD. After adjustment for sex, age, birthweight-for-gestational age and maternal age, children with SRBD had higher BMI -z -score, systolic BP, insulin and HOMA-IR levels, and lower HDL-cholesterol, when compared to those without SRBD, but these associations were lost when adjusting to BMI z -score. Analyzing obese children with the same regression model, those with SRBD presented lower HDL-cholesterol than those without SRBD. Conclusions: Our results identified a male predominance of SRBD in pre -pubertal children and highlighted the potential contribution of SRBD to cardiovascular risk in obese children.