A Newer Perspective on Diabetes and Depression

In diabetes, there is an ongoing chronic inflammatory process that has been the focus of many latest research efforts. Several inflammatory markers like C-peptide, TNF-α, pro-inflammatory cytokines, are augmented, thus causing sickness and depression.

Another biomarker that has been the focus of investigations is Dipeptidyl peptidase-4 (DPP4), which is elevated in diabetes. DPP4 inhibitor drugs are already being widely used to treat diabetes and related disorders. Increased DPP4 activity has been shown to be associated with higher blood glucose levels, CPR, nitrotyrosine, and 8-iso-PGF2a; all of these have been shown to increase the risk of diabetes significantly.

In one of the cross-sectional studies, data of 1,482 type 2 diabetes patients aged between 40-82 was analyzed, and the direct relationship between the depression and rising levels of DDP4 activity was found. It seems that high levels of DPP4 activity lead to higher chances of depression through three pathways, that is, hyperglycemia (high blood glucose), inflammation, and oxidative stress.