TABLE I.

Subject Characteristics and Plasma Orexin A Levels in Prader-Willi Syndrome and Healthy Unrelated Sibling Control Children

Characteristic	Prader-Willi syndrome (N = 23) [mean ± SD (range)]	Control subjects (N = 18) [mean ± SD (range)]	F-value	P-value
Age	8.2 ± 2.0 yr (5–11 yr)	8.2 ± 2.3 yr (5–11 yr)	0.07	0.79
BMI	20.7 ± 5.0 (l4–28)	18.2 ± 3.3 (15–25)	2.2	0.15
BMI z-score	0.96± 1.4(13–32)	0.52 ± 1.35 (12–26)	1.1	0.31
Total body fat	33.1 ± 13.1% (13–54%)	24.0 ± 10.1% (10–47%)	5.5	0.02*
Orexin levels [mean pg/ml ± SD (range, N)]
All subjects	1028 ± 358 (475–1,910, N = 23)	609 ± 351 (165–1,220, N = 18)	14.8	<0.001*
Female subjects (N = 18)	880 ± 458 (165–1,910, N = 10)	656 ± 345 (165–1,114, N = 8)	4.0	0.06
Male subjects (N = 23)	1005 ± 257 (475–1,401, N = 13)	570 ± 359 (165–1,220, N = 10)	11.1	0.003*

^*Indicates statistical significance for linear regression analysis at P< 0.05 level of alpha.