Taking the injectable type 2 diabetes drug Victoza (liraglutide) led to a reduction in both body fat and sugar intake as well as improved blood glucose control in overweight adults with type 1 diabetes, according to a new study published in the journal Diabetes, Obesity and Metabolism.
Victoza was developed as a treatment for type 2 diabetes, and is not currently approved as a treatment for type 1. But researchers were interested in whether this drug could have beneficial effects in overweight people with type 1, since a higher-dose version of the same drug — sold as Saxenda — is approved as a treatment to help with weight loss in certain overweight or obese people. Since people with type 1 are susceptible to the same weight-related problems as anyone else — including the possibility of developing insulin resistance — it stands to reason that a type 2 diabetes drug that is also approved as a weight-loss treatment could be worth investigating.
The study’s participants were adults with type 1 diabetes who had used an insulin pump for at least a year, and had an A1C level (a measure of long-term blood glucose control) greater than 7.5%, indicating less than optimal blood glucose control. Participants also had a body-mass index (a measure of body weight that takes height into account) greater than 25, categorizing them as overweight or obese. They were randomly assigned, in equal numbers, to take either Victoza or a placebo (inactive injection) once daily, gradually increasing the amount injected to reach a final dose of 1.8 milligrams daily by the third week of the study in the Victoza group. Both groups continued their daily injections for a total of 26 weeks.
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Differences between Victoza, placebo groups
By the end of the study period, members of the Victoza group had lost an average of 4.6 kilograms (10.1 pounds) of body fat and 2.5 kilograms (5.5 pounds) of lean mass. In contrast, members of the placebo group lost an average of only 0.3 kilograms (0.7 pounds) of fat mass and 0.0 kilograms of lean mass. Participants in the Victoza group also reduced their energy intake by more than those in the placebo group — by an average of 263 calories, compared with 215 calories — but this difference was too small to be statistically significant. But members of the Victoza group reduced their intake of added sugars by an average of 27%, while members of the placebo group increased their intake of added sugars by an average of 14% over the course of the study.
On average, members of the Victoza group saw an average drop of 2.4 points on the BMI scale, while those in the placebo group saw a drop of only 0.2. The Victoza group also saw an average drop in A1C of 5 mmol/mol (0.45%), while the placebo group saw an average increase in A1C of 2 mmol/mol (0.18%). There was also a significant improvement in the Victoza group in the amount of time spent within the target blood glucose range — an increase of 4.6% or 66 minutes, compared with a drop of 4.8% or 69 minutes in the placebo group. The average daily dose of insulin decreased by 4.9 units in the Victoza group, while it increased by 2.8 units in the placebo group.
“It can be debated whether the body composition changes observed in liraglutide-treated participants in the present study should be characterized as beneficial,” the study authors wrote, since losing lean mass is generally not considered to be a benefit. But the improvements in blood glucose control and reduced use of insulin appear to be beneficial outcomes, and might be explained at least in part by a reduced intake of sugar and weight loss in the Victoza group. More research is needed, the study authors noted, to learn about how taking Victoza or related drugs could alter food preferences in a way that leads to differences in measured outcomes like body fat and insulin use.
Want to learn more about Victoza and other medicines in its drug class? Read “GLP-1 Agonists: Getting to Know These Diabetes Drugs Better.”