Oral Session 1
Saturday, April 28, 2018 | 2:15pm-3:45pm | Room 342B
CARDIOVASCULAR CONSEQUENCES OF SLEEP DISORDERED BREATHING IN CHILDREN BORN PRETERM
Rosemary Horne (Australia)*
Blessy Thomas (Australia)
Kamsajini Thillainathan (Australia)
Maeve Delahunty (Australia)
Aidan Weichard (Australia)
Margot J. Davey (Australia)
Gillian M. Nixon (Australia)
Lisa M. Walter (Australia)
Population cohort studies show that sleep disordered breathing (SDB) is 3 to 6 times more likely in preterm born children than those born at term. Being born preterm is associated with an increased risk of developing cardiovascular complications as is SDB. In this study we aimed to compare the effects of SDB on cardiovascular outcomes in a group of children born preterm with a group of children born at term referred to our sleep laboratory for assessment of SDB.
Materials and methods
100 children (3-12 years) referred for clinical assessment of SDB at the Melbourne Children’s Sleep Centre between 2011 and 2016 were recruited; 50 were ex-preterm (< 37 weeks of gestation) and 50 were born at term, matched for age and SDB severity. All children underwent overnight polysomnography (PSG) using either a Compumedics Series E or Grael Sleep System (Compumedics, Melbourne, Australia). PSG data were transferred to specialised data analysis software (LabChart 7.2, ADInstruments, Sydney, Australia) for analysis. Epochs containing wake after sleep onset or artefact were excluded. The mean heart rate for each child for wake and sleep stages, N1, N2, N3 and REM sleep across the entire night were calculated. Power spectral analysis of the ECG recording was used to determine heart rate variability as a measure of autonomic control.
Ex-preterm children were born at 29.3 ± 3.6 (mean ± sem) weeks of gestational age. There were no other differences in the demographic, sleep and respiratory characteristics between the groups. Heart rate tended to be lower in the ex-preterm children in each sleep state and this reached statistical significance in N3 (p<0.05). High Frequency power was greater in the ex-preterm children in both N2 and N3 (p<0.05 for both) and Total Power was greater in N3 (p<0.05). There was no relationship between gestational age at birth and either heart rate or any heart rate variability parameter in the ex-preterm children.
Preterm born children matched for age and SDB severity with children born at term showed no differences in sleep and respiratory characteristics, however they did exhibit increased parasympathetic tone during NREM sleep. Changes in High Frequency ECG power are attributed to respiration and this suggests, that despite similar SDB, ex-preterm children exhibited increased work of breathing compared to their term born peers.