In reply: Starting insulin therapy

In Reply: We thank Dr. Weiss for his insightful comments and for the opportunity to clarify a number of points from our article.

We agree that controlling the fasting glucose should not take months. As mentioned in our article, adjusting the basal insulin dose should be done with 2 to 4 units every 2 to 3 days in order to reach the fasting glycemic goal. Applying this approach and systematically titrating the NPH, glargine, or detemir insulin will smoothly decrease the fasting glucose within 12 weeks, as described in the 24-week ¹ and 52-week ² treat-to-target trials in which basal insulin was added to the oral therapy in patients with type 2 diabetes.

When basal insulin is no longer sufficient to reach a target hemoglobin A _1c, a glucagon-like peptide-1 receptor agonist or prandial insulin can be used. The basal-bolus or twice-daily premixed insulin analogues can also be considered as the initial therapy, depending on the patient, disease, and drug characteristics. ³ We agree that once a prandial insulin regimen is initiated, the dose titration can be done based on preprandial or postprandial blood glucose measurements, as shown in Table 2 in our article. However, adding the prandial insulin without first optimizing the basal therapy was considered a limitation of the Orals Plus Apidra and Lantus (OPAL) study, ⁴ which investigated the addition of one prandial insulin injection to basal glargine insulin. ⁵ As a consequence, the subsequent studies investigating the effects of initiating and titrating the preprandial rapid-acting insulin (as a single dose or using a stepwise approach) in patients inadequately controlled with once-daily basal insulin and oral antidiabetic drugs had run-in periods of 12 to 14 weeks, in order to optimize the basal insulin dosage and achieve target fasting blood glucose levels of 110 mg/dL or less. This approach had the additional benefit of achieving a target hemoglobin A _1c level of less than 7% in a significant number of patients (up to 37%), ⁶ before starting the preprandial insulin. ^6–8

Regardless of the regimen selected, titration of the insulin doses can only be achieved with understanding the pharmacodynamic characteristics of each type of insulin used. ⁹