An increased risk of incident diabetes with statin therapy have been reported in several studies. However, it is not recommended to limit the use of statin for this reason since the absolute risk increase was small, and the cardiovascular event rate reduction with statins overweighed the risk of new diabetes (Scatter N et al. Lancet, 2010). Moreover, each statin may have different effect on the development of incident diabetes. In the West of Scotland Coronary Prevention Study, pravastatin therapy reduced the hazard of becoming diabetic by 30%. Also, with pravastatin use, an increase in adiponectin level, which is related to the improvement in insulin sensitivity, has been reported. In this clinical trial, the investigators are aiming to evaluate the effect of pravastatin on insulin resistance, insulin secretion, glycemic control, and adiponectin level in participants with prediabetes or early diabetes by assigning them in a 24 weeks of pravastatin therapy group or in a placebo group.