Switching or adding insulin to GLP-1 receptor agonists and its benefits in type 2 diabetes

The authors aimed to determine the benefits of adding or switching to insulin therapy in type 2 diabetes patients not responding to treatment with glucagon-like peptide-1 receptor agonists (GLP- 1RA).

The authors concluded that the earlier addition of insulin was associated with better glycemic control. The authors suggest that patients not responding to a GLP-1RA alone would benefit from adding insulin therapy rather than switching to insulin. 

GLP-1RAs (such as Victoza) are a common treatment option used in patients with type 2 diabetes. They function by increasing insulin secretion to improve blood glucose control and reduce body weight. Insulin is another treatment option used in diabetes management. Both of these therapies affect body weight differently.

GLP-1RAs have been seen to significantly reduce weight in patients, whereas insulin has been seen to significantly increase body weight. The aim of both treatments is to maintain a steady glucose level in the blood, and to avoid hyperglycemia (very high levels of blood glucose). It is not clear whether adding insulin to GLP-1RA treatment is more effective than switching to insulin alone in patients with high blood glucose levels.

The aim of this study was to determine if adding or switching to insulin treatment was beneficial in patients with type 2 diabetes treated with GLP-1RA.

66,583 patients were used in this study with a 24-month follow-up. Each patient had received GLP-1RA treatment without previous insulin treatment for at least 6 months. 39,599 patients added insulin to their treatment. 4,706 patients switched to insulin after their GLP-1RA treatment ended.

The average highest HbA1c (a measurement of average blood glucose levels over the past three months) change in patients who remained on GLP-1RA treatment without adding insulin was seen within 6 months of starting treatment. Patients who added insulin to their treatment within 6 months experienced 18% higher odds of achieving HbA1c levels of less than 7% at 24 months, compared to patients who added insulin at a later period. Patients who added insulin significantly reduced their HbA1c by 0.55%. No glycemic benefit was seen in patients who switched to insulin. 

Patients who added insulin to their treatment experienced a slightly higher weight reduction at 12 months (2.93 kg) and 24 months (3.40 kg) compared to patients who did not add or switch to insulin (2.50 kg at 12 months and 3.31 kg at 24 months).

The authors concluded that the earlier addition of insulin was associated with better glycemic control. The authors suggest that patients not responding to a GLP-1RA alone would benefit from adding insulin therapy rather than switching to insulin.