USING STABLE ISOTOPES TO ASSESS REDUCED PHYSICAL-ACTIVITY OF INDIVIDUALS WITH PRADER-WILLI-SYNDROME

The contribution of reduced levels of physical activity to the positiv e energy balance found in most individuals with Prader-Willi syndrome is not known. We assessed total energy expenditure using stable isotop es and resting energy expenditure using open circuit indirect calorime try in a group of 10 children with this syndrome. The difference betwe en these two measures is primarily the energy cost of activity and is often called a physical activity level. After adjusting for age, we fo und that the physical activity level values of these children were sig nificantly reduced in comparison to children who did not have Prader-W illi syndrome. Increasing activity levels in children with Prader-Will i syndrome will raise total energy expenditure and may help to control their development of weight gain.