Combining a GLP-1 receptor agonist plus insulin proves more effective than other diabetes therapies

“A powerful and safer alternative to insulin” achieved robust glucose control for diabetes with no increased risk of hypoglycaemia or weight gain, conclude the authors of a systematic review of therapies published in The Lancet
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The combination of a glucagon-like peptide-1 receptor (GLP-1) agonist plus basal insulin offered the “ideal triumvirate”, according to Laura Young and John Buse from the University of North Carolina, USA, in an accompanying commentary to the meta-analysis^[2]
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The systematic review included 15 studies that compared GLP-1 agonist and basal insulin combination therapy with other antidiabetic drugs in 4,348 adults with type 2 diabetes
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The researchers, led by Ravi Retnakaran, from Mount Sinai Hospital, Toronto, Canada, noted that the high cost of both GLP-1 agonists and insulin analogues is likely to be the major barrier to widespread adoption of the treatment.

Combination therapy reduced glycated haemoglobin (HbA1c) by a mean of 0.44% more than other therapies and significantly improved the likelihood of achieving an HbA1c of 7.0% or lower, with a relative risk (RR) of 1.92. Furthermore, combination therapy was associated with a mean 3.22 kg reduction in body weight and did not increase the risk of hypoglycaemia (RR 0.99) versus other therapies.

Compared with full basal-bolus insulin regimens, the combination of GLP-1 agonist plus insulin resulted in a marginal 0.1% reduction in HbA1c, a 33% lower risk of hypoglycaemia and a mean 5.66-kg reduction in weight.

Retnakaran and colleagues say their data indicate that combining a GLP-1 agonist with basal insulin “can achieve the ideal triumvirate of short-term outcomes in diabetes management: potent glucose-lowering capacity without increased hypoglycaemia or weight gain”.

“Our findings clearly lend support to the use of GLP-1 agonists in combination with basal insulin in the clinical management of patients with type 2 diabetes.”

Victoria Ruszala, a diabetes pharmacist at North Bristol NHS Trust, said that the study provided reassurance about the co-prescription of GLP-1 agonists and basal insulin, already widely practised and endorsed by expert bodies such as the Association of British Clinical Diabetologists.

Ruszala added that while the meta-analysis summarised the overall benefits of combination therapy, there are likely to be differences in the efficacy and side-effects associated with individual GLP-1 agonists.