Background: Overweight or obesity contributes to the development of type 2 diabetes mellitus (T2DM) and increases cardiovascular risk. Exenatide, a glucagon-like peptide-1 receptor agonist, significantly reduces glycated hemoglobin (A1C) and body weight and improves cardiovascular risk markers in patients with T2DM. As weight loss alone has been shown to reduce A1C and cardiovascular risk markers, this analysis explored whether weight loss contributed importantly to clinical responses to exenatide once weekly.
Methods: A pooled analysis from eight studies of exenatide once weekly was conducted. Patients were distributed into quartiles from greatest weight loss (Quartile 1) to least loss or gain (Quartile 4). Parameters evaluated for each quartile included A1C, fasting plasma glucose (FPG), blood pressure (BP), heart rate, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol, triglycerides, and the liver enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST).
Results: The median changes from baseline in body weight in Quartiles 1-4 were -6.0, -3.0, -1.0, and +1.0 kg, respectively. All quartiles had reductions in A1C (median changes -1.6, -1.4, -1.1, and -1.2%, respectively) and FPG (-41, -40, -31, and -25 mg/dL, respectively), with the greatest decreases in Quartiles 1 and 2. Most cardiovascular risk markers (except diastolic BP) and liver enzymes improved in Quartiles 1 through 3 and were relatively unchanged in Quartile 4. Higher rates of gastrointestinal adverse events and hypoglycemia were observed in Quartile 1 compared with Quartiles 2 through 4.
Conclusions: Exenatide once weekly improved glycemic parameters independent of weight change, although the magnitude of improvement increased with increasing weight loss. The greatest trend of improvement in glycemic parameters, cardiovascular risk factors including systolic BP, LDL-C, total cholesterol, and triglycerides, and in liver enzymes, was seen in the patient quartiles with the greatest reductions in body weight.