Methylglyoxal, diabetes mellitus and diabetic complications.

A large literature has developed around methylglyoxal (MG) concerning its role in diabetes mellitus (DM) and in the development of diabetic complications. This is related to the observation that levels of reactive aldehydes, especially 2-oxoaldehydes such as MG, are elevated in DM. There are numerous metabolic origins of MG that are accentuated in DM. MG has effects on insulin secretion from pancreatic beta-cells and is a major precursor of advanced glycation endproducts (AGE). Consequently, MG has a role in primary DM as well in the etiology of long-term complications. There is an extensive literature concerning the enzymes involved in the metabolism of MG, especially the glyoxalase system and aldose reductase. In addition, there is a rapidly developing literature on the direct and indirect effects of MG on signaling pathways that impact DM. This review attempts to integrate this DM-associated literature related to MG.