Sas statistical analysis software version 0

Data were presented as mean and/or median ± standard deviation of raw and/or natural log-transformed orexin A levels by diagnosis (PWS or healthy unrelated siblings) and gender. Natural log-transformed orexin levels were analyzed using analysis of variance (ANOVA) and the general linear model with controls for age, gender, body mass index (BMI) or total body fat. Data falling below the limits of detection for the Milliplex assay were replaced with one half the minimum detectable level of orexin A (150.5 pg/ml) as described previously [Butler et al., 2015 (link)]. Final transformed data met statistical criteria for the assumption of normality with equal variance and near linear residual plots. Statistical analyses and descriptive statistics were generated with SAS statistical analysis software version 0.4 (SAS Inc., Cary, NC) with P values <0.05 considered significant.

Data were presented as mean and/or median ± standard deviation of raw and/or natural log-transformed oxytocin levels by diagnosis (PWS or unrelated siblings). Natural log-transformed oxytocin levels were utilized to meet normality criteria required for analysis using simple analysis of variance (ANOVA) and general linear model adjusting for diagnosis, gender, age and body mass index (BMI). Data falling below detection limits of the Milliplex assay were replaced with one half of the minimum detectable level of oxytocin (4.675 pg/ml) as reported in previous studies using this methodology [Ashwood et al., 2010 ; Manzardo et al., 2012 (link)]. Final transformed data met statistical criteria for the assumption of normality with equal variance and near linear residual plots. The frequency of oxytocin levels below detection limits were statistically analyzed by PWS diagnosis and gender using Fisher Exact Test. Statistical analyses and descriptive statistics were generated with SAS statistical analysis software version 0.4 (SAS Inc., Cary, NC) with P-values <0.05 were considered significant.