Total RNA was extracted with TRIreagent (SIGMA-ALDRICH) from fat biopsies. RNA expression was analyzed on the Affymetrix human GeneChip HGU133 Plus 2.0 array (Affymetrix) covering over 47,000 transcripts genome-wide. Labelled RNA was hybridized onto Affymetrix arrays, washed, stained and scanned for fluorescence intensity corresponding to gene expression level.