Determining the Factors that Influence the Insulin Requirements in Type 2 Diabetic Patients

ABSTRACT

BACKGROUND: The initial insulin dose is often determined by clinical experience or with a formula using the body weight. However, it may be difficult to determine the initial insulin dose because various factors such as insulin sensitivity and the glycemic status can influence the insulin requirement. The purpose of this study was to assess the factors that influence the initial insulin requirement in insulin naive patients with type 2 diabetes mellitus. METHODS: A total 128 patients who were admitted for glycemic control were investigated. The patients were managed with long-acting insulin glargine and rapid-acting insulin lispro. RESULTS: The basal insulin requirement was positively correlated with waist circumference, body mass index (BMI), the HbA1C, AST, ALT, fasting plasma glucose and 2-hour postprandial glucose levels and the homeostasis model assessment of insulin resistance (HOMA-IR), but it was negatively correlated with age and the stimulated C-peptide level. The daily insulin requirement was positively correlated with waist circumference, BMI, the HbA1C, AST, ALT, triglyceride, fasting plasma glucose and 2-hour postprandial glucose level and HOMA-IR, but it was negatively correlated with age. On the multiple linear regression analysis, the basal insulin requirement was independently associated with BMI (beta = 0.507, p < 0.001), the 2-hour postprandial glucose level (beta = 0.307, p < 0.001), the ALT level (beta = 0.214, P = 0.015) and the meal-stimulated C-peptide level (beta = -0.209, P = 0.010). The daily insulin requirement was independently associated with BMI (beta = 0.508, p < 0.001) and the 2-hour postprandial glucose level (beta = 0.404, p < 0.001). CONCLUSION: Our results show that the BMI and 2-hour postprandial glucose level are useful predictors of the initial insulin requirement in insulin naive type 2 diabetic patients. It may be prudent to consider the other various factors that influence the insulin requirement together when insulin therapy is required.