Obesity and Complications in Prader-Willi Syndrome
Obesity is the most obvious physical feature of Prader-Willi syndrome
(PWS). About one-third of individuals with untreated PWS weigh more than 200% of
their ideal body weight. The paradox of the underweight infant with PWS evolving
into an overweight or obese child and adult has led to considerable speculation
regarding pathophysiology [Mutch: 2006]
[Miller: 2006]
[Holsen: 2006]
Four recognized factors contributing to obesity in PWS are:
- Hyperphagia or overeating beginning in early childhood (between 1-6 years)
- Reduced physical activity relating to decreased muscle tone and quantity, and increased fat mass
- Reduced metabolic rate (about 60% of normal) related to decreased muscle mass
- Inability to vomit
Obesity-related findings include:
- Heart failure
- Hypertension
- Thrombophlebitis and chronic leg edema
- Ulcers and cellulitis
- Orthopedic problems
- Abnormal lipid profiles
- Diabetes mellitus, type II
Other findings seen at an increased rate when compared to the general
population with obesity include:
- Obstructive sleep apnea
- Narrowing of the airway
- Impaired respiratory function
- Hypoventilation
- High carbon dioxide levels
- Increased risks of complications with general anesthesia
- Hypometabolism
Effective strategies to prevent or limit obesity are necessary throughout
the lifespan of individuals with PWS:
- Weight control through diet restriction (about 60% of normal daily caloric intake)
- Exercise programs tailored to the individual’s health status, age, and jointly established goals
- Sex hormone therapy and growth hormone therapy, which leads to increased height, decreased fat mass, increased muscle mass, and increased metabolic rate
Funding:
This page was developed in partnership with the Heartland Genetic Services Network and was funded in part by a Health Resources Services Administration (HRSA) cooperative agreement (U22MC03962). We appreciate
the Prader-Willi Syndrome Association (USA) for their outstanding support of individuals with PWS and their families and for the information they provide on their website
– www.pwsausa.org – to which we have provided several links within the Diagnosis Module.
Page Bibliography
Holsen LM, Zarcone JR, Brooks WM, Butler MG, Thompson TI, Ahluwalia JS, Nollen NL, Savage CR.
Neural mechanisms underlying hyperphagia in Prader-Willi syndrome.
Obesity (Silver Spring).
2006;14(6):1028-37.
PubMed abstract / Full Text
Miller J, Kranzler J, Liu Y, Schmalfuss I, Theriaque DW, Shuster JJ, Hatfield A, Mueller OT, Goldstone AP, Sahoo T, Beaudet
AL, Driscoll DJ.
Neurocognitive findings in Prader-Willi syndrome and early-onset morbid obesity.
J Pediatr.
2006;149(2):192-8.
PubMed abstract
Mutch DM, Clément K.
Unraveling the genetics of human obesity.
PLoS Genet.
2006;2(12):e188.
PubMed abstract / Full Text