Adding exenatide to insulin treatment in patients with type 2 diabetes

This controlled trial looked at adding exenatide (Byetta) to intensive insulin treatment for patients with type 2 diabetes (T2D) who still had high blood sugar. It found that the exenatide improved blood sugar control and reduced body weight in these patients.

T2D is a metabolic condition in which the body does not respond well to the hormone insulin, which controls the amount of glucose (sugar) in the blood. Many people with T2D use synthetic insulin to keep their blood glucose under control. However, over time insulin can cause weight gain, which worsens T2D. Additionally, some patients using insulin still do not have fully controlled blood glucose.

Glycogen-like peptide 1 (GLP-1) is another hormone involved in metabolism, obesity, and diabetes. GLP-1 is released by the gut after eating. This hormone prepares the pancreas to release insulin, which improves the body’s ability to control glucose after eating. GLP-1 also prevents the stomach from emptying too early after eating, leading to increased fullness and satiety. GLP-1 functions less well for people with obesity and T2D.

Exenatide is a medication which mimics GLP-1 and is a treatment for T2D. Exenatide and other GLP-1 mimics are typically used alongside diet, or a single daily injection of long-acting insulin. It is not clear whether adding exenatide is beneficial for patients already using multiple daily insulin injections or an insulin pump.

This study included 46 patients with T2D and incompletely controlled blood glucose (HbA1c over 7.5%). 28 patients used injections of exenatide twice daily before breakfast and dinner. 18 patients in a control (comparison) group used injections of an inactive placebo. All patients continued using their usual insulin regimen of multiple daily injections or an insulin pump. Patients were followed for 26 weeks (six months).

Glycated hemoglobin (HbA1c) measures how many red blood cells contain attached glucose, and is related to blood glucose control over the previous 2 to 3 months. Patients taking exenatide had significantly improved HbA1c compared to those taking placebo (0.62% decrease vs. 0.08% increase). 

Patients taking exenatide lost an average of 2.55 kg (5.6 pounds) over the six months. In contrast, those taking placebo gained 1.29 kg (2.8 pounds).

Common side effects of exenatide included nausea (39%) and vomiting (11%). No patients experienced hypoglycemia (abnormally low blood glucose).

This study found that adding exenatide to intensive insulin treatment improved blood glucose control and prevented weight gain for patients with T2D.

This study was sponsored by AstraZeneca, the manufacturer of exenatide. The number of patients in this study was very small. Larger studies are needed.