Effects of Insulin Therapy and Oral Hypoglycemic Agents on Glycemic Control for Type 2 Diabetes Mellitus Patients in China-A Case Control Study.

Objective: The purpose of the study was to compare glycemic control in patients with type 2 diabetes (T2DM) receiving insulin therapy (IT) or oral hypoglycemic agents (OHA), and explore associations between treatment modality and pancreatic beta-cell function.

Methods: A matched, case-control study was conducted from April, 2016 to November, 2016. 2 272 patients with T2DM were identified from electronic medical records at four academic hospitals in China. Based on 1 136 eligible patients using IT, eligible 1 136 OHA patients were matched by age and duration at a ratio of 1:1. Logistic regression was used to examine the relationship between IT and glycemic control. Multiple linear regression addressed impact factors of HOMA-β.

Results: There was no significant difference between IT and OHA groups in gender, age, diabetes duration, body mass index (BMI), fasting plasma glucose (FPG), systolic blood pressure (SBP), serum lipids and smoking history (p>0.05). We stratified subjects by diabetes duration, only when the duration was less than 5 years, HbA1c in OHA group was superior to IT (P=0.017). There were no significant differences between groups in HbA1c when disease duration was≥5 years. Even in subjects with short diabetes duration (<5 years), IT did not significantly impact glycemic control (p=0.071, OR=0.577). Multiple linear regression analysis showed that IT (p=0.001), diabetes duration (p=0.038), BMI (P<0.001), sulfonylurea use (P=0.001) were significant and independent predictors of HOMA-β.

Conclusions: In patients with short diabetes duration (<5 years), oral hypoglycemic therapy achieved better glycemic control than insulin therapy. Moreover, insulin use was not an impact factor of poor glycemic control. In addition, using insulin can protect beta-cell function.