Participants are asked to take part in an eight month study to find out if middle-aged and older people with Type 2 diabetes who have added risk factors for heart disease can even out their blood sugar levels. They will start on long-acting insulin, mealtime insulin, and metformin, if they are not already on these medications. Their kidney function tests must be normal and they must not be allergic to metformin. Then, after a 2 month run-in phase, they must be willing to be assigned by chance into one of two groups. This means that they will have a 50/50 chance (like flipping a coin) of being in either group. Half of them will be started on the new medicine known as Byetta rather than the meal-time insulin and the other half will remain on the meal-time insulin during the next 6 months (26 weeks) to see which group has more steady blood sugars. They will be asked to use a continuous blood sugar monitoring system called DexCom. A sensor is inserted under the skin in the same areas the insulin is injected. The DexCom can check their blood sugars 24 hours of the day and night and will be worn until 7 days of recordings are collected. In the same 7 day period, they will also be asked to wear a Holter or Telemetry monitor that will record their heart beats and rhythm which will be compared to the blood sugar readings. They will also use home glucose meters to check their glucose levels about 3 to 4 times a day. The study will take place at 12 centers in the United States and enroll about 120-130 people.