Figure 7.
Proposed model of the role of nicotinamide overload in the development of type 2 diabetes. Normally, if nicotinamide intake is slightly more than the body needs, excess nicotinamide will be detoxified rapidly and eliminated mainly via the N1-methylnicotinamide to 2Py pathway, which involves liver and skin functions (left). Frequent excess nicotinamide intake, low N1-methylnicotinamide detoxification, or sweat gland inactivity induces a substantial rise in plasma N1-methylnicotinamide concentrations and residence time after each meal, and consequently induces oxidative stress and insulin resistance (right). The change trends are indicated by red arrows or line thickness.