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

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

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

Many individuals with Down syndrome (DS) have breathing problems during sleep. This is called obstructive sleep apnea syndrome (OSAS). OSAS is very common in individuals with Down syndrome because of the shape of their face and tongue and because of their low muscle tone. OSAS can cause a lot of health problems including behavioral and learning problems as well as heart problems. The purpose of this research study is to look at the effects of treating OSAS in individuals with Down syndrome with a machine called Continuous Positive Airway Pressure (CPAP). The investigators want to see if treatment of OSAS improves learning, behavior and heart problems.

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.

Down syndrome, Obstructive sleep apnea syndrome, Continuous positive airway pressure, sham or placebo CPAP

Group 2 are individuals with OSAS who will receive sham or placebo continuous positive airway pressure (CPAP) for 4 months.

Group 3 are individuals with normal breathing during sleep who will not receive any intervention and will be used as a control group.

Continuous positive airway pressure is a machine used with sleep which compresses air delivered via a nasal mask and thus helps stent the airway open.

Sham or placebo CPAP is a machine used instead of therapeutic CPAP. This machine is similar to a therapeutic CPAP machine but has built in leaks and does not deliver pressure. It is not effective in treating OSAS.

The primary aim of the study is to assess the relationship between obstructive sleep apnea syndrome (OSAS) and the neurocognitive and behavioral outcomes of individuals with Down syndrome. Sleepiness was assessed using the pediatric version of the Epworth Sleepiness Scale (ESS). The ESS is a self-administered questionnaire with 8 questions. It provides a measure of a person's general level of daytime sleepiness, or average sleep propensity in daily life. The ESS asks people to rate, on a 4-point scale (0, low to 3, high) their usual chances of dozing off or falling asleep in 8 different situations or activities that most people engage in as part of their daily lives. The total ESS score provides an estimate of a general characteristic of each person's average level of sleepiness in daily life (0= no chance of dozing/no daytime sleepiness to 24=high chance of dozing/lots of daytime sleepiness).

The change in behavioral domain was measured by the Child Check Behavior List. The CBCL is a widely used method of identifying problem behavior in children. Problems are identified by a respondent who knows the child well, usually a parent or other care giver. There are 2 versions based on the child's age (CBCL/1½-5 for use children 18 months-5 years; the CBCL/6-18 for children aged 6-18 years). The checklists consists of a number of statements about the child's behavior and responses are recorded on a scale: 0 = Not True, 1 = Somewhat or Sometimes True, 2 = Very True or Often True. The preschool checklist contains 100 questions and, school-age checklist contains 120 questions. 8 sub-scores (1 for each of 8 syndromes: anxious/depressed, withdrawn depressed, somatic complaints, social problems, thought problems, attention problems, rule-breaking behavior and aggressive behavior) are calculated, each ranging from 0 (normal) to 16 (clinical behavior).

The change in left ventricular mass index score, measured on echocardiography, was used to assess the relationship between obstructive sleep apnea syndrome and cardiovascular function of individuals with Down syndrome. Left ventricular (LV) mass was calculated from M-mode measurements of the LV end-diastolic dimension, the thickness of the interventricular septum and the thickness of the LV posterior wall, and presented as a z-score.

As secondary outcome of the second aim, we will use the distance walked during the 6 minute walk test.

Inclusion Criteria: Aged 8-20 years Down syndrome (based on the characteristic phenotype) Families provide informed consent and child provides assent Exclusion Criteria: Subjects and families who do not speak English well enough to undergo psychometric testing. Subjects living in institutions where there is no primary caregiver to participate in the neurocognitive/behavioral battery. Major chronic lung disease such as chronic aspiration. Previous or current CPAP therapy. Participation in a weight loss program. Craniofacial or neuromuscular conditions other than those associated with DS. Untreated hypothyroidism. Participants with normal thyroid function tests will be included in the study.