Data preprocessing and DEGs analysis

The probe-level data in the CEL files were converted into expression measures using the Affy package (version 1.48.0) (16) with R software (https://www.r-project.org/). Missing data were inputted and data normalization was performed using quartile normalization (17). A boxplot graph was produced to present the chip data distribution and the median values. When the median values were consistent subsequent to normalization, the chip data were used for DEGs analysis.

The omental adipose tissues of normal-weight children were considered as the controls. DEGs in omental adipose tissues between obese children samples and normal controls were identified by the limma package (version 3.26.8) (https://bioconductor.org/packages/release/bioc/html/limma.html) (18). The P-values and log fold change (logFC) were calculated. P<0.01 and |logFC| >1 were considered as the cut-off criteria.