Obesity has become one of the biggest health problems in the world, especially among older adults. As people age, extra body weight can place more pressure on the heart, joints, blood vessels, and many other parts of the body.
Obesity in older adults is linked to serious health conditions such as heart disease, high blood pressure, diabetes, sleep apnea, reduced mobility, disability, and lower quality of life.
Doctors have long known that losing weight can improve health in many people with obesity. However, treating obesity in older adults can be more difficult than in younger people.
Older individuals are often more medically fragile, may already have several chronic illnesses, and may be more vulnerable to medication side effects. Because of this, researchers have been carefully studying whether newer obesity drugs are both safe and effective for people over the age of 65.
Now, a large new analysis of clinical trials has provided encouraging results for a widely discussed obesity drug called semaglutide.
The study was led by Professor Luca Busetto from the University of Padova in Italy together with researchers from several institutions, including scientists from Novo Nordisk, the company that manufactures semaglutide.
Semaglutide belongs to a class of medicines called glucagon-like peptide-1 receptor agonists, often shortened to GLP-1 drugs. These medicines were first developed to help treat type 2 diabetes because they improve blood sugar control and help the body release insulin more effectively.
Later, researchers discovered that these drugs also strongly reduce appetite and help many people lose weight.
In recent years, semaglutide has become one of the best-known obesity drugs in the world because clinical trials showed significant weight loss in many patients.
However, information about how well the drug works in older adults has been more limited. Researchers wanted to better understand whether semaglutide would remain effective and safe in people aged 65 years and older, since older adults may face greater risks of frailty, falls, side effects, and medical complications.
To investigate this, the researchers combined data from several major clinical studies known as the STEP trials. These trials tested once-weekly injections of semaglutide at a dose of 2.4 milligrams in adults with obesity or overweight.
The analysis included data from STEP 1, 3, 4, 5, 8, and 9. Only people without diabetes were included because weight loss tends to be smaller in people with diabetes, and researchers wanted to avoid mixing different patient groups.
The study included adults aged 65 years and older who either had obesity, defined as a body mass index of at least 30, or were overweight with at least one obesity-related health problem.
Participants were randomly assigned to receive either semaglutide or a placebo, which is an inactive treatment. All participants also received lifestyle advice to support weight loss, including healthier eating and physical activity. One trial also included intensive behavioral therapy.
The researchers followed participants for 68 weeks, which is more than one year.
In total, the combined trials included 4,523 participants, and 358 of them were aged 65 years or older. Most participants in the older group were between 65 and 74 years old, while a smaller number were aged 75 or older.
At the start of the study, the average participant was 69 years old, weighed about 99 kilograms, had a body mass index of 36.6, and a waist circumference of 115 centimeters. About 72% of the participants were women.
The results showed that semaglutide led to major weight loss compared with placebo.
After 68 weeks, older adults taking semaglutide lost an average of 15.4% of their body weight, while those receiving placebo lost about 5.1%. Waist size also improved significantly, decreasing by an average of 14.3 centimeters in the semaglutide group compared with 6 centimeters in the placebo group.
The researchers also looked at how many people achieved large amounts of weight loss.
About two-thirds of participants taking semaglutide lost at least 10% of their body weight, compared with only about 15% of people receiving placebo. Nearly half of semaglutide users lost at least 15% of their weight, and more than one-quarter lost at least 20%, which is considered a very large amount of weight reduction.
The study also found improvements in several important markers linked to heart and metabolic health.
Participants taking semaglutide showed better blood pressure, cholesterol levels, blood fats, inflammation markers, and blood sugar control compared with placebo.
Researchers also examined waist-to-height ratio, which is another measure of body fat linked to health risks. More people in the semaglutide group reached healthier waist-to-height ratios compared with placebo.
In addition, many participants improved their BMI category over the course of the study. About 27% of older adults taking semaglutide reached a BMI below 27, which is considered a healthier weight range, compared with only 5.5% in the placebo group.
The safety findings were also important.
Overall rates of side effects were similar between semaglutide and placebo groups. However, serious adverse events were somewhat more common in the semaglutide group.
The most common side effects included constipation and dizziness, which are already known side effects of GLP-1 medications. Fractures and low blood sugar events were rare and occurred in less than 1% of participants in both groups.
Professor Busetto said the findings suggest that semaglutide works in older adults similarly to how it works in younger adults. He noted that obesity is extremely common among people over the age of 65 in many high-income countries and contributes heavily to disability, poor quality of life, and obesity-related disease.
The researchers believe the findings support the use of semaglutide in carefully selected older patients with obesity.
Still, experts caution that semaglutide is not a simple cure and may not be appropriate for everyone.
Older adults can be more vulnerable to muscle loss, weakness, dehydration, and side effects during weight loss treatment. Doctors therefore stress that medical supervision is very important when using these medications.
The findings are especially important because obesity treatment in older adults has often been overlooked in the past. Many doctors worried that weight loss in older age could worsen frailty or lead to muscle loss.
This study suggests that carefully managed treatment may still provide meaningful health benefits for many older individuals.
The analysis also highlights the growing role of GLP-1 drugs in modern medicine. Researchers are continuing to study whether these medications may help not only with obesity and diabetes, but also with heart disease, kidney disease, sleep apnea, and other obesity-related conditions.
The study findings suggest that semaglutide may offer substantial weight loss and health improvements for many older adults with obesity. The large amount of weight reduction seen in the study is clinically significant and may help lower risks linked to heart disease and metabolic illness.
However, the higher rate of serious adverse events shows that caution is still necessary, especially in medically vulnerable older populations. Another limitation is that most participants were between 65 and 74 years old, meaning less information is available for people over 75.
Overall, the research supports semaglutide as a potentially valuable treatment option for obesity in older adults when used carefully under medical supervision.
The study was conducted by researchers from the University of Padova and collaborators from Novo Nordisk and was based on data from the STEP clinical trial program.
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Source: University of Padova.
