Sleep phenotype in children with Down syndrome – altered sleep architecture and sleep-disordered breathing

The aim of the study was to assess sleep architecture and breathing in sleep in children with Down syndrome. The study was conducted by using overnight video-polysomnography (V-PSG) in children with Down syndrome and age-matched children from the general population. Analysis of polysomnographic parameters revealed that compared to the norms of healthy ageand maturitymatched children from the general population, children with Down syndrome had significantly shorter sleep latency (p=0.007), shorter total sleep time (p=0.004), lower sleep efficiency (p=0.010), less NREM1 sleep phase (p=0.0002), less NREM3 sleep phase (p=0.034), less REM sleep (p=0.034) in favour of more NREM2 phase but not significantly (p=0.069), and spent more time awake after sleep onset (p=0.0002). Children with Down syndrome had significantly more obstructive sleep apnoeas and hypopnoeas per hour (higher obstructive sleep apnoeas and hypopnoeas index) (p=0.008), but less central sleep apnoea per hour (lower central apnoeas index) (p=0.041), which led to the nonsignificantly lower total apnoea-hypopnoea index (p=0.762) in children with Down syndrome. The mean and longest apnoea duration did not differ significantly between these two groups. Children with Down syndrome had a significantly lower mean and nadir oxygen saturation (p=0.008 and p=0.001, respectively). In conclusion, the majority of respiratory complications in children with Down syndrome can be prevented by raising awareness of sleep disturbances in children with Down syndrome among their parents and health care providers and by introducing early routine V-PSG in the follow up of these children.