A weekly dose of a diabetes drug appears to result in significant weight loss in people with obesity, in a development experts have called groundbreaking.
According to the World Health Organization, obesity causes 1.2 million deaths in Europe each year and the UK has one of the worst obesity rates.
Efforts to combat the disease have long focused on diet and exercise, but many people who lose weight this way find that they regain it over time.
Now researchers say a diabetes drug used alongside such procedures may help people with obesity. Participants in a 72-week study lost up to 20% of their body weight.
An international team reports in the New England Journal of Medicine that they randomly divided 2,539 overweight or obese participants into four equal groups.
One group was offered a self-administered placebo injection once a week for 72 weeks, while the other three groups were offered either 5mg, 10mg or 15mg of a drug called tirzepatide. All participants also received regular lifestyle counseling to help them stick to low-calorie meals and at least 150 minutes of physical activity per week.
On average, the participants had a body weight of 104.8 kg or 16.5 stone, with 94.5% considered obese. The majority were white and female, and none had diabetes.
The results of those who adhered to the assigned intervention – almost 82% of the sample – show that the participants who were given 5 mg of tirzepatide each week lost an average of 16.1 kg at the end of the 72-week period, those who were Those given 10 mg lost an average of 16.1 kg by 22.2 kg and those given 15 mg lost an average of 23.6 kg. Those given a placebo injection lost an average of 2.4 kg.
The team adds that 91% of the participants given the highest dose of tirzepatide lost 5% or more of their body weight, compared with 35% of those given the placebo. Fifty-seven percent of those given the highest dose lost compared to 20% or more of their body weight 3% of those assigned the placebo.
“We should treat obesity as we treat any chronic disease – with effective and safe approaches that target the underlying disease mechanisms – and these results underscore that tirzepatide could do just that,” said Dr. Ania Jastreboff of Yale University, the lead author of the study, which was presented during the 82nd Scientific Sessions of the American Diabetes Association.
The study comes after Britain’s National Institute for Health and Care Excellence (Nice) approved the use of another drug, semaglutide, in February for certain groups of people with obesity.
Prof Rachel Batterham, an obesity expert at University College London who was not involved in the work, said tirzepatide works like semaglutide by mimicking hormones in the body that help people feel full after eating and which are often at low levels in people with obesity.
While semaglutide mimics only one hormone, tirzepatide mimics two, which may explain why the latter seems to have a greater effect.
“Weight loss is about improving a person’s health. If you want to improve the really difficult complications of obesity, then you need 15-20% weight loss. If you want to improve someone’s heart failure, or get rid of their obstructive sleep apnea, reduce their risk of dying from cardiovascular disease, then we need a much greater weight loss that we can achieve and sustain with diet alone.” said Batterham.
Tom Sanders, professor emeritus of nutrition and dietetics at King’s College London, said higher doses of tirzepatide resulted in more weight loss, but they caused more side effects, mainly nausea, vomiting and diarrhea, while a major concern with this class of drugs has been their effects on the pancreas.
“This class of drugs only works if participants stick to the calorie-restricted diet prescribed with the drug so it’s not a silver bullet,” he said.
also dr Simon Cork, Lecturer in Physiology at Anglia Ruskin University, said there were challenges.
“These drugs are game-changers in the obesity space, but they only work as long as the drug is taken,” he said. “Current guidance for Nice regarding semaglutide is to take the drug for a maximum of two years, after which it will not be offered again. We know that for many people this is very likely to result in a weight loss reversal, as is likely to be the case with tirzepatide.”
Naveed Sattar, a professor of metabolic medicine at the University of Glasgow who was not involved in the work, said the latest findings are good news.
However, he said that like Semaglutide, Tirezpatide would be expensive for many years and its use would be limited at first.
“The advent of these new drugs does not mean that people should abandon their lifestyles, as preventing obesity in the first place is far better than treating it at a late stage when a lot of damage has already been done,” he said.
“Fortunately, methods that help people improve their diet continue to evolve as we learn what works better. But of course improving the food environment would have the greatest impact of all and should therefore remain a priority for government.”