Obstructive Sleep Apnea and Neurocognitive and Cardiovascular Function in Children With Down Syndrome

All individuals participating in the study will be evaluated for obstructive sleep apnea
syndrome (OSAS) with a baseline sleep study. Based on the results of the sleep
study,individuals with OSAS will be randomly assigned into two groups. One group will
receive continuous positive airway pressure (CPAP) and the other intervention group will
receive sham CPAP(placebo) for four months. CPAP is a machine with a mask that fits over the
nose, is worn during sleep and helps keep the airway open. Sham CPAP (placebo) is a machine
that looks and sounds like a CPAP machine but does not give pressure so it does not treat
OSAS. Individuals with normal breathing during the sleep study will not receive a machine,
and will serve as controls.

Individuals will also have baseline tests including blood tests, an echocardiogram (pictures
of the heart), a walking test and learning tests. After 4 months, the baseline tests will be
repeated in all participants. At the end of the study, all individuals with OSAS will get
treatment.

Inclusion Criteria:

1. Aged 8-20 years

2. Down syndrome (based on the characteristic phenotype)

3. Families provide informed consent and child provides assent

Exclusion Criteria:

1. Subjects and families who do not speak English well enough to undergo psychometric
testing.

2. Subjects living in institutions where there is no primary caregiver to participate in
the neurocognitive/behavioral battery.

3. Major chronic lung disease such as chronic aspiration.

4. Previous or current CPAP therapy.

5. Participation in a weight loss program.

6. Craniofacial or neuromuscular conditions other than those associated with DS.

7. Untreated hypothyroidism. Participants with normal thyroid function tests will be
included in the study.