New York: Trials of a Danish-made injectable drug called liraglutide (trademark name Victoza) have revealed that it reduces weight and the prevalence of cardiovascular risk factors in obese people without diabetes.

High doses of liraglutide, were also found to cause greater weight loss than orlistat (marketed over-the-counter as Alli), according to a report in the medical magazine, The Lancet.

In developing countries obesity levels have risen dramtically in the past two decades and in some European countries 30% of the population are overweight. Around 50% of all adults in Europe are classified as overweight.

Obesity increases the risk of degenerative diseases including high blood pressure, diabetes, and atherosclerosis, and all risk factors for heart disease.
Moreover, obesity is associated with a reduced quality of life. Few safe and effective drugs are currently available for the treatment of obesity. Therefore, alternative approaches to weight loss that are safe and well tolerated and that can lower the risks associated with obesity are needed. In this randomised controlled trial, the authors studied the effect of liraglutide on bodyweight and tolerability in obese individuals without type 2 diabetes.

The study, led by Professor Arne Astrup, Department of Human Nutrition, University of Copenhagen, Copenhagen, Denmark, took place in 19 sites in Europe, and analysed 564 people (18-65 years, body-mass index 30-40 kg/m²). Each was assigned to 1 of 4 liraglutide doses (1.2 mg, 1.8 mg, 2.4 mg, or 3.0 mg, n = 90-95) or to placebo (n = 98) administered once a day subcutaneously, or to orlistat 120 mg (n = 95) administered orally 3 times a day. All participants also followed a calorie-restricted diet, which contained approximately 500 calories less than they needed each day. Participants also increased their physical activity throughout the trial, including the 2-week run-in.

Participants on liraglutide lost significantly more weight than did those on placebo and orlistat. Mean weight loss with liraglutide doses 1.2, 1.8, 2.4 and 3.0 mg was 4.8 kg, 5.5 kg, 6.3 kg, and 7.2 kg respectively, compared with 2.8 kg with placebo and 4.1 kg with orlistat. A higher proportion of individuals (76%) lost more than 5% weight with liraglutide 3.0 mg than with placebo (30%) or orlistat (44%).

Liraglutide reduced blood pressure at all doses. At the start of the study, around one-third of patients in each group had pre-diabetes, that is, poor blood glucose control not yet bad enough to qualify as diabetes. Liraglutide reduced the prevalence of pre-diabetes (84%-96% reduction) with 1.8-3.0 mg per day.

Nausea and vomiting occurred more often in individuals on liraglutide than in those on placebo, but adverse events were mainly transient and rarely led to discontinuation of treatment.

The authors say: “Treatment with liraglutide, in addition to an energy-deficit diet and exercise programme, led to a sustained, clinically relevant, dose-dependent weight loss that was significantly greater than that with placebo (all doses) and orlistat (vs liraglutide 2.4 mg and 3.0 mg).”

They conclude: “The results of this study indicate the potential benefit of liraglutide, in conjunction with an energy-deficit diet, in the treatment of obesity and associated risk factors. Liraglutide offers a new mode of action for the treatment of obesity and improved efficacy compared with currently available therapies. Its effect on pre-diabetes suggests that it might be important for treating obese pre-diabetic individuals.”

They add that further studies, with longer follow-up than 20 weeks, are now needed to establish the long-term risk-benefit profile for liraglutide.

In an editorial accompanying the article, George A Bray, MD, Division of Clinical Obesity and Metabolism, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, says: “Today’s important report shows a dose-related reduction of food intake and bodyweight in overweight and obese individuals treated with liraglutide.”

Dr Bray adds that one limitation to the use of drugs such as liraglutide is that they require an injection. He says: “Whether long-term use of an injectable drug is palatable as a treatment for obesity is yet to be established.”