SERPINF1 and obesity due to melanocortin 4 receptor deficiency: Therefore, PEDF contributes to the onset and maintenance of chronic inflammation in obesity and obesity-induced insulin resistance, and related complications such as MetSyn and type 2 diabetes mellitus.[61,62] Serum levels of PEDF are higher in patients with MetSyn and type 2 diabetes.[62,63] PEDF expression is elevated in proportion to the accumulation of the number of components of MetSyn in the general population.