LEP and Insulin resistance: Thus, as expected, the pro-inflammatory adipokines leptin, adipsin, insulin, C-peptide, chitinase 3-like 1, TNF-R1 and TNF-ligand superfamily member 13 (TNFSF13 or APRIL) were found in higher levels in the serum profile of the obese group relative to lean subjects, and osteocalcin, which improves insulin resistance by decreasing inflammation [46], was found in lower levels amongst obese individuals.