This is a retrospective cohort study of patients with T2DM who were treated with exenatide twice daily as a part of their diabetes care for at least 12 months. The objective of this study is to investigate the influence of T2DM susceptibility gene polymorphisms (NOS1AP, KCNQ1, TCF7L2, WSF1, GLP-1R, etc.) on the efficacy of GLP-1 RA (exenatide, liraglutide, etc.), to identify the variables that can predict the efficacy of GLP-1 RA, and to evaluate the weight of these variables on the efficacy.

T2DM is a polygenic genetic disease. The individual differences in the efficacy of antidiabetic drugs are caused by the cumulative effect of multiple gene polymorphisms, and are related to environmental factors and lifestyle. The results of single gene polymorphism cannot fully explain the individual differences in the efficacy of antidiabetic drugs. Verifying the correlation between T2DM gene polymorphisms and the efficacy of antidiabetic drugs, clarifying the genetic determinants of individual differences in the efficacy of antidiabetic drugs, and predicting the efficacy and side effects of antidiabetic drugs are of great significance for the formulation of precise medication regimens for T2DM patients.

Many guidelines recommend the preferential use of GLP-1 RA after single drug or multiple oral hypoglycemic drugs and basic insulin therapy for poor glycemic control. However, the clinical responsiveness to GLP-1 RA varies among patients with T2DM. It has been reported that genetic factors are the important reasons for individual variation in therapeutic response of antidiabetic drugs. At present, dozens of gene loci related to therapeutic response of antidiabetic drugs have been screened, which are of great clinical significance in guiding clinical individualized treatment, improving the efficacy and safety of drugs, and reducing the drug costs.

GLP-1 RA was injected subcutaneously at standard dose and frequency for consecutive 6 months. The patients were visited at moths 0, 3, and 6, and medical histories, physical examinations, and routine clinical laboratory tests were performed during these visits. The general anthropometric parameters considered for this study were height (m), weight (kg), and waist and hip circumferences (cm) at baseline, 3 months and 6months after exenatide treatment.

Patients who had an HbA1c reduction ≥1.0% or HbA1c <7.0% after exenatide treatment for six consecutive months were considered responders, while patients who failed to achieve this decrease were considered non-responders. The clinical data were collected and analyzed to determine the variables that could predict the efficacy of GLP-1 RA, and to evaluate the weight of the influence of these variables on the efficacy.

Inclusion Criteria:

1. a diagnosis of T2DM
2. a body mass index (BMI) of 20-35 kg/m2
3. an HbA1c of 7.0%-12%, an age of 25-70 years
4. required data available at baseline and 6 months after GLP-1RA therapy.

Exclusion Criteria:

1. Patients with serious diseases such as acute myocardial infarction, cerebral vascular accident, trauma, kidney or liver diseases, severe gastrointestinal dysfunction, and history of pancreatitis
2. patients receiving GLP-1 analogues, weight loss drugs, glucocorticoids, drugs affecting gastrointestinal peristalsis in the past 3 months
3. those with missing data at the time points of baseline, 3 months, and 6 months after GLP-1 RA therapy.