Incretin-based therapies in clinical practice: from efficacy to effectiveness. Focus on liraglutide

Liraglutide is a GLP-1 analogue introduced in Italy in 2010; its efficacy and safety have been tested within the comprehensive "LEAD program". The aim of this paper was to evaluate whether and to what extent routine practice outcomes are consistent with research findings.

One diabetes outpatient clinic reviewed data of patients receiving incretin-based therapies. Differences in characteristics of patients treated with liraglutide, exenatide, or DPP-IV inhibitors were evaluated. The subgroups of patients treated with liraglutide, exenatide or DPP-IV inhibitors (sitagliptin, vildagliptin, saxagliptin) and followed for at least eight months were analyzed longitudinally. Hierarchical linear models for repeated measurements were applied to assess trends over time.

Incretin-based treatments were prescribed to 312 patients (liraglutide: 130, exe-natide: 72, DPP-IV inhibitors: 110). Diabetes duration, HbA1c levels, and BMI were substantially higher in exenatide and liraglutide groups than in the DPP-IV inhibitors group. Liraglutide was often administered in combination with metformin alone, while exenatide was often added to two or more drugs. Overall, 20 (15.4%) liraglutide interruptions were recorded, especially due to nausea. Treatment drop out rate was higher in exenatide and DPP-IV inhibitors groups (in exenatide mostly for gastrointestinal side effects, in DPP-IV for inefficacy). After eight months, overall levels of HbA1c were reduced from 8.1±1.1 to 7.1±0.8 (P<0.0001) with liraglutide. Furthermore, fasting blood glucose was reduced by 37.9±6.2 mg/dL (P<0.0001), body weight by 4.1±0.5 kg (P<0.0001), systolic blood pressure by 8.9±2.7 mmHg (P<0.001), total cholesterol by 8.8±4.1 mg/dL (P=0.04), and triglycerides by 24.4±14.6 mg/dL (P=0.07). Patients who had their therapy replaced at baseline from exenatide or DPP-IV had a further reduction in HbA1c, FBG and body weight.

Liraglutide is penetrating diabetes care with results strictly mimicking the promising beneficial effects found in the LEAD program.