Effectiveness and Safety Study of the Dexcom G4™ Continuous Glucose Monitoring System

The purpose of this study is to evaluate the effectiveness and safety of the Dexcom G4 System when used as an adjuvant to blood glucose testing over a 7-day period in people \>18 years-old with diabetes mellitus. The primary objective is to characterize the System performance with respect to laboratory reference venous sample measurements. The device performance will be primarily evaluated in terms of point and rate accuracy of the G4 System in reference to YSI. Safety of the G4 System will be characterized by Adverse Device Effects and Serious Adverse Device Effects experienced by study participants.