Effect of the Anti-oxidant N-acetylcysteine on Beta-cell Function in Type 2 Diabetes

Beta-cell dysfunction is a critical feature of type 2 diabetes (T2DM). High glucose levels can exacerbate beta-cell dysfunction with oxidative stress proposed as a major mediator of this "glucotoxic" effect. High glucose levels have also been shown to contribute to vascular dysfunction and inflammation and these adverse responses decreased with the use of antioxidants. The hypothesis is that antioxidants improve beta-cell function in individuals with elevated glucose levels by decreasing oxidative stress. In this study the investigators will specifically test whether the antioxidant N-acetylcysteine (NAC) can improve beta-cell function in individuals with type 2 diabetes by decreasing oxidative stress. This initial study will be a dose finding study to determine the tolerability of 600 mg versus 1200 mg twice a day of NAC and the effects of NAC treatment on beta-cell function, glucose tolerance and oxidative stress markers in persons with type 2 diabetes. Study procedures will include a fasting urine sample and performance of a 2 hour 75 gram oral glucose tolerance test at baseline, after 2 weeks on 600 mg twice daily NAC and again after 2 more weeks on 1200 mg NAC twice a day.