The strongest correlations between serum leptin levels, hormones, G-ratio (galactose incorporation assay) and gene expression data were observed between leptin, its gene and G-Ratios data (r<sub>s</sub> = - 0.68) and (r<sub>s</sub> = - 0.94) respectively with lower circulating leptin in CG patients with reduced IgG galactosylation.