Prader-Willi Syndrome and Complications from Obesity
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
Authors & Reviewers
Author: | Merlin G. Butler, MD, PhD |
2014: revision: Merlin G. Butler, MD, PhDR |
2008: update: Merlin G. Butler, MD, PhDA |
2008: first version: Kyna Byerly, MS, CGCCA |
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