Tirzepatide Weight Loss Trial
Obesity is one of the biggest health challenges of our time. The chronic disease impairs the quality of life increasing the risk of other serious conditions such as
In addition, it also increases the risk of several types of cancer.
Surgery that reduces the patient’s stomach, combined with lifestyle changes, is the most effective obesity treatment. But in recent years, several drugs for chronic diseases have also been developed. There are currently four approved anti-obesity drugs in the EU; orlistat, liraglutide, naltrexone/bupropion and semaglutide.
The former works by reducing fat absorption in the intestine and the remaining three by controlling the appetite.
Tirzepatide FDA Approval
In the current study, the researchers examined tirzepatide, a so-called GIP / GLP 1 agonist. It stimulates receptors for glucose-dependent insulin-releasing peptide GIP and glucagon-like peptide 1, GLP 1. One of them affects food intake and energy consumption. And the other amplifies the effect. Tirzepatide was recently approved in the United States as a treatment for type 2 diabetes.
The study was a randomized, placebo-controlled phase III study with 2,539 adult participants. They had a body mass index, BMI of 30 or more, or 27 or more and at least one weight-related complication, excluding diabetes. The mean age was 44.9 years, and 67 per cent of the participants were women. The study started in December 2019 and was conducted in nine countries.
For 72 weeks, participants received either tirzepatide (5 mg, 10 mg or 15 mg) or a placebo once a week. The treatment period included a dose increase period of up to 20 weeks. Participants would also eat balanced meals with a deficit of 500 calories per day and engage in physical activity for at least 150 minutes per week.
In total, 86 per cent of the participants completed the treatment. At the study’s end, the weight loss percentage was:
-15 per cent in those who received 5 mg of tirzepatide
-19.5 per cent of those who had received 10 mg
-29 per cent of those who had received 15 mg.
In the placebo group, the average weight loss was 3.1 per cent.
The results also showed improvements in, among other things, waist measurements, blood pressure, fasting insulin levels and lipid levels. 95.3 per cent of participants with prediabetes at the beginning of the study had returned to normal blood sugar levels after 72 weeks. The corresponding figure in the placebo group was 61.9 per cent.
About 10% of participants who had received tirzepatide reported at least one side effect.
This can be compared with 72 per cent in the placebo group. The most common side effects were nausea, diarrhoea and constipation with mild or moderate severity. More side effects occurred when the dose was increased.
Six% of participants reported severe side effects. These were evenly distributed across the drug groups and the placebo group. In total, 21% of these were related to covid-19. Eleven deaths were reported, seven in the drug group and four in the placebo group.
What are Tirzepatide Side Effects?
According to the researchers, tirzepatide shows an “unusually significant degree” of weight loss. They also note that there was an expected effect on the occurrence of side effects, as the study was conducted almost entirely during the corona pandemic.
The researchers point out, among other things, the sample size and that the vast majority completed the treatment as some of the study’s strengths. They make the results relatively generalizable, they say.
One limitation they mention is that the participants in the study may represent a subpopulation with a more significant commitment to losing weight than the general population with obesity.
They also mention that only 5.5% of the participants had a BMI between 27 and 30, which counts as overweight. Therefore, further studies are needed in this patient group.