Liraglutide as add-on therapy to insulin in type 2 diabetes mellitus: a retrospective, observational study from a daily clinical practice setting in Switzerland.

introductionIn most patients with type 2 diabetes mellitus (T2DM) and progressive beta-cell insufficiency, insulin therapy is required to achieve sufficient glycemic control. However, insulin therapy may lead to weight gain and increasing risk of hypoglycemia. Glucagon-like peptide-1 receptor agonists are being used as add-on therapy to insulin with favorable metabolic effects. Nonetheless, to date only few studies exist reporting on the combination of liraglutide and insulin with a short follow-up period. The aim of this study was to evaluate the efficacy and safety of liraglutide as add-on to insulin in patients with T2DM over a time period of up to 24-28 months.

methodsData of patients with T2DM, treated with insulin and liraglutide at an outpatient clinic in a tertiary referral hospital from October 2009 until December 2011 were retrospectively examined (n = 36). Glycated hemoglobin (HbA1c), weight, total daily insulin dose and side effects were assessed 5-8 months prior to liraglutide, at baseline and at follow-up visits after 3, 6, 12-16 and 24-28 months.

resultsMedian HbA1c decreased significantly from 7.7% [interquartile range (IQR) 7.0-8.6] at baseline to 6.8% (IQR 6.5-7.7, p = 0.001) at 3 months and 6.9% (IQR 6.3-7.6, p = 0.0001) at 6 months, but re-increased thereafter (at 24-28 months, median 7.5%, IQR 7.1-8.2, p = 1.0). Median weight decreased significantly from 99.8 kg (IQR 81-110) at baseline to 97.7 kg (IQR 81.2-108.2, p = 0.027) at 3 months, but rose again thereafter. Insulin dosage did not change significantly over time. No severe hypoglycemia or major side effects occurred.

conclusionsIn this observational study, adding liraglutide to insulin in daily clinical practice reduced HbA1c significantly within 6 months, but there may be a non-sustainable effect during long-term treatment.