Safety and effectiveness of insulin glargine

This study examined the effectiveness and safety of two forms of insulin glargine in people with type 2 diabetes (T2D). It determined that both forms reduced HbA1c (measures average blood glucose over the last 3 months), but the more concentrated form was less likely to cause hypoglycemia (dangerously low blood glucose).

People with T2D can control their symptoms, at first, with lifestyle changes (such as a healthy diet and exercise) and non-insulin medications. However, many people will eventually need insulin to maintain control.

Insulin is the hormone needed to lower blood glucose levels. Basal insulin helps to keep glucose levels steady between meals. Insulin glargine is a slightly altered form of insulin that is designed to provide a steady supply of insulin to the body. Insulin glargine 300 units/ml  (Gla-300) is a more concentrated form of insulin glargine 100 units/ml (Gla-100). The safety and effectiveness of Gla-300 has been shown in clinical trials. In clinical trials, the treatment and the characteristics of the participants are strictly controlled.  It is unclear whether the same results will be seen in real-world settings outside of clinical trials.

Physicians who regularly treat people with T2D were asked to complete a questionnaire. They answered questions about their patients’ medical history. Data about 553 adults with T2D who had started treatment with insulin glargine was examined. 390 had never taken insulin before. Of these 390, 298 started treatment with Gla-300 and 92 started treatment with Gla-100. The remaining 163 patients had switched to treatment with Gla-300 from another basal insulin. The average follow-up time was 4 months.

In the patients newly treated with insulin, there was no major difference in the final dose of insulin needed in those who took Gla-100 and in those who took Gla-300. Both groups had significant reductions in HbA1c. HbA1c levels fell by 1.21% in those treated with Gla-300 and 1.12% in those treated with Gla-100.

Those treated with Gla-300 were 69% less likely to experience hypoglycemia than those treated with similar doses of Gla-100. However, people who took Gla-100 were more likely to also be taking sulfonylureas (another drug that may cause hypoglycemia). This may have affected the results.

In the patients who switched to Gla-300 from another basal insulin, the daily required dose of insulin was lower after switching. HbA1c levels also fell by 0.95% after switching. These patients were also 83% less likely to experience hypoglycemia after switching.

The study concluded that Gla-300 can reduce HbA1c levels as much as Gla-100, and is less likely to cause hypoglycemia than Gla-100.

Sanofi, the manufacturers of insulin glargine, funded this study.

Discuss different forms of basal insulin with your physician.