Hypoglycemia in Prader-Willi Syndrome
Condition: Prader Willi Syndrome; Hypoglycemia
MeSH terms: Prader-Willi Syndrome; Hypoglycemia; Syndrome
Study type: Observational

Summary: 
      This project will study whether infants with Prader-Willi Syndrome experience low blood
      sugars after short periods of fasting. This study will also evaluate metabolic markers in the
      blood to determine if infants with Prader-Willi Syndrome process energy differently than
      other children during fasting.
    

Detailed description: 
      This study will include outpatient admission to the clinical research center for IV
      placement, blood draws from the IV, poking the participants finger to obtain small amounts of
      blood and monitored 6 hour fast. A fast is when a person goes without food for a certain
      period of time. The participant will not be fasted longer than 6 hours.

      The participant will arrive to the outpatient clinical research center at approximately 7am.
      A parent will be expected to stay with the participant at all times. The participant's finger
      will be poked for blood (requires approximately one drop of blood) soon after arrival to make
      sure his blood sugar is not already low. If the participant's blood sugar is low on arrival
      to the Clinical Research Center, additional blood will be drawn through his vein (a little
      more than half a teaspoon) and he will not have to complete the rest of the study. If his
      blood glucose is above 60 mg/dl, the participant will be given an opportunity to eat prior to
      starting the fast. A small tube will be placed in the participant's vein at the beginning of
      the fast to make additional blood draws easier. 1/10th a teaspoon of blood will be sent for
      cortisol testing when the IV is placed. Cortisol is a hormone that is important for control
      of blood sugar. In addition, the participant's finger will be pricked every hour for blood to
      monitor his blood sugar by bedside meter. Each finger prick will require approximately one to
      two drops of blood. A test to look at fat breakdown (ketones) will sometimes be checked using
      the same blood obtained when pricking the finger to check blood sugar. If a blood sugar of
      less than 70 mg/dl is found, blood sugars will be checked by finger prick every 30 minutes
      instead of every hour. If finger prick blood glucose is less than 65 mg/dl, blood will be
      collected and sent to the clinical research center lab to make sure that the true blood sugar
      reading is not lower than what is seen on the bedside meter (requires approximately 1/10
      teaspoon of blood). If a blood sugar of less than 60 mg/dl is found, the fast will end and
      blood will be collected through the IV line (small tube placed through the vein). The
      participant will be monitored by a nurse during the fast. She will check his blood pressure,
      pulse and respiratory rate periodically to make sure he is comfortable. After final blood
      collection, the participant will be allowed to feed normally and his IV will be removed.
      During the entire study, we expect to collect at least ¾ of a teaspoon of blood from the
      participant. No more than 1.2 teaspoons of blood will be collected from the participant
      during this entire study.

      If a blood sugar less than 60 mg/dl is found at any time, blood will be drawn from a vein in
      the participant's arm and the study will end. He will then be allowed to eat. If he has a low
      blood sugar and is unable to feed the way he normally does, sugar water/gel may be given by
      mouth or sugar water may be given by the tube placed in his vein. If the participant normally
      is fed by a tube placed in his stomach, sugar water may be given through this tube.
    

Intervention name(s): Infants with Prader-Willi Syndrome
Intervention type(s): Other
Intervention description(s): Participants will be admitted to the outpatient clinical research center for IV placement, blood draws from the IV, poking the participants finger to obtain small amounts of blood and monitored 6 hour fast.
Observational model: Case-Only
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Infants with Prader-Willi Syndrome who have not yet started growth hormone therapy
      
Keywords: Prader Willi Syndrome; Hypoglycemia; Fasting study