Energy expenditure at rest and during sleep in children with Prader-Willi syndrome is explained by body composition.
BACKGROUND
Obesity in Prader-Willi syndrome (PWS) seems to be related to a low basal metabolic rate (BMR). In addition, abnormal sleep patterns reported in PWS might affect sleeping metabolic rate (SMR).


OBJECTIVE
Our objective was to assess BMR and SMR adjusted for fat-free mass in young PWS patients.


METHODS
Subjects were 17 PWS patients (10 females and 7 males aged 7.5-19.8 y) and 17 obese control subjects matched for sex and bone age. SMR was measured in a respiratory chamber, BMR with a ventilated-hood system, and body composition by deuterium dilution.


RESULTS
BMR and SMR were significantly lower in the PWS group than in the control group (5.36 +/- 1.18 and 4.62 +/- 1.08 MJ/d compared with 6.38 +/- 1.55 and 5.60 +/- 1.52 MJ/d, respectively; P < 0.05). When fat-free mass was included in the analysis, multiple regression showed no differences in BMR and SMR between groups. When weight was included in the analysis instead of fat-free mass, SMR was lower in the PWS group. Fat-free mass was lower in the PWS group both as an absolute value and when adjusted for height.


CONCLUSIONS
BMR and SMR are low in young patients with PWS because of a low fat-free mass.
van Mil
E A
EA
Departments of Human Biology, Pediatrics, Clinical Genetics, and Methodology and Statistics, Maastricht University, Maastricht, Netherlands. g.vanmil@hb.unimaas.nl
Westerterp
K R
KR
Gerver
W J
WJ
Curfs
L M
LM
Schrander-Stumpel
C T
CT
Kester
A D
AD
Saris
W H
WH
D000293:Adolescent; D000328:Adult; D001481:Basal Metabolism; D001823:Body Composition; D015992:Body Mass Index; D002648:Child; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D008297:Male; D011218:Prader-Willi Syndrome / Q000378:metabolism*; D012044:Regression Analysis; D012146:Rest / Q000502:physiology*; D012890:Sleep / Q000502:physiology*