Semaglutide: Results of major study into safety of Ozempic and Wegovy released

The definitive results of a major new study were published on Monday (May 13) in the prestigious medical journal Naturemedicine. The researchers showed that weekly injections of the fat busting drug semaglutide produced a major (20%) reduction in cardiac events such as heart attack, stroke and heart failure even in men and women without diabetes.

The study involving 17,604 adults participating lead by a team from Pennington Biomedical Research Centre, Los Angeles USA was called the SELECT cardiovascular outcomes trial. The magnitude of the beneficial effect of this class of drugs called GLP-1 receptor agonists is now on a par with statins, which were first introduced in 1990.

On top of the reduction in serious heart disease, patients treated with semaglutide for over 200 weeks, on average lost 10% of their weight and reduced their waist circumference by 7.7cm compared to those given placebo (dummy) injections. What’s more, weight loss was sustained for up to four years and helped both sexes, all races and body sizes.

Interestingly, the reduction in cardiac risk was not directly linked to degree in weight loss. The benefit was the same if participants lost 5% or 20% of their weight. Prof Deanfield, a senior Cardiologist at University College London (UCL) London, speaking ahead of the European Congress on Obesity (ECO) in Venice, said these findings suggest other mechanisms, independent or additional to weight loss, could be reducing the heart risks such as a positive impact on blood sugar, blood pressure or inflammation, as well as direct effects on the heart muscle and vessels.

They all seem to relatively well tolerated. Some users have complained of indigestion and wind and there are very rare reports of gall bladder disease or thyroid tumours although these links have not been substantiated.

Alarm bells were raised when a 150 cases of suicidal ideations, were reported to the  Icelandic medicines agency. In response potential risk, a team of scientists from the Centre for Science, Health in Cleveland, USA, scrutinized the health records of 240,618 overweight or obesity patients who were prescribed semaglutide plus a further 1.5 million patients who had not taken the injections. Fortunately, they reported that risk of suicidal thoughts were actually less than half in the semaglutide group.

The use of semaglutide (Ozempic or Wegovy) and liraglutide (Saxenda) has exploded over the last two years, expanding so much that manufacturers have had trouble keep up with demand, creating shortages and rationing.

These new studies and reassurances relating to safety are very likely to increase the use of these drugs even further and there is a big market. Across the world obesity rates have tripled over the last 30 years. In the UK, more than a quarter of the population are defined as obese (having a body mass index (BMI) greater than 30kg/m2) and nearly 60% as overweight (having a BMI of 25–30).

Although these studies are encouraging experts still agree that these drugs should only be offered under medical supervision and should not be a replacement for healthy weight reduction lifestyle strategies which include:

• Avoiding sugary foods and drinks
• Increasing exercise and avoiding sedentary behaviour
• Eating more whole foods and fibre and less processed high-calorie foods
• Enhancing gut flora and gut health
• Avoiding snacking between meals
• Adding phytochemical rich spices, herbs and blueberries to your diet
• Extending the overnight fast

In a word of caution, it must be noted that the overweight participants in these studies all had pre-existing cardiovascular disease. Further trials are ongoing to established whether these drugs could reduce the risk in people without pre-exiting heart disease. Likewise, it would be useful to obtain robust data to establish whether weight reduction using these drugs results in a lower risk of other obesity associated disease such as blood clots, breast, uterus, of bowel, kidney and oesophageal cancers.