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).Our objective was to assess BMR and SMR adjusted for fat-free mass in young PWS patients.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.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.BMR and SMR are low in young patients with PWS because of a low fat-free mass.
van Mil, E. A., Westerterp, K. R., Gerver, W. J. M., Curfs, L. M. G., Schrander-Stumpel, C. T. R. M., Kester, A. D. M., & Saris, W. H. M. (2000). Energy expenditure at rest and during sleep in children with Prader-Willi syndrome is explained by body composition. American Journal of Clinical Nutrition, 71(3), 752-756. https://doi.org/10.1093/ajcn/71.3.752