The reductive power provided by
nicotinamide adenine dinucleotides is invaluable for several cellular processes. It drives metabolic reactions, enzymatic activity, regulates genetic expression and allows for the maintenance of a normal cell redox status. Therefore, the balance between the oxidized (
NAD(+)) and the reduced (
NADH) forms is critical for the cell's proper function and ultimately, for its survival. Being intimately associated with the cells' metabolism, it is expected that alterations to the
NAD(+)/
NADH ratio are to be found in situations of
metabolic diseases, as is the case of diabetes.
NAD(+) is a necessary cofactor for several
enzymes' activity, many of which are related to metabolism. Therefore, a decrease in the
NAD(+)/
NADH ratio causes these
enzymes to decrease in activity (reductive stress), resulting in an altered metabolic situation that might be the first insult toward several pathologies, such as diabetes. Here, we review the importance of
nicotinamide adenine dinucleotides in the liver cell and its fluctuations in a state of
type 2 diabetes mellitus.