If you want to lose weight, you may be looking into or may have been prescribed a weight-loss medication containing semaglutide, such as Ozempic®. While medications that contain semaglutide can help you achieve your weight-loss goals, they may come with the risk of dangerous side effects.
According to a study on mice from the University of Alberta, Ozempic could shrink muscles, including the heart muscle. The study authors claim that some people who have been prescribed Ozempic, including patients suffering from type 2 diabetes, could still see more benefits than risks. However, people who take Ozempic without meeting eligibility criteria may need to be wary of the drug.
The study authors discovered that heart muscle shrank in lean and obese mice that were injected with Ozempic. The same effect was found in cultured human heart cells.
The mice did not suffer any negative health consequences from having smaller heart muscles. However, the authors emphasize that the mice were not examined over a long-term period and humans have the potential to develop long-term consequences from Ozempic, such as heart disease resulting from changes in the function and structure of the heart.
In another study, Mounjaro® (tirzepatide) was associated with reduced left ventricular mass and less fat surrounding the heart in patients with obesity-related heart failure. However, this seemed to emphasize a beneficial effect with Mounjaro reducing the number of heart failure events. 1 Tirzepatide is a medication similar to semaglutide.
What is Semaglutide?
Ozempic (semaglutide), Mounjaro (tirzepatide) and other such medications belong to a class of drugs known as GLP-1 agonists, which were first introduced for diabetes management and then for weight loss. Semaglutide tends to greater facilitate weight loss compared to liraglutide, another GLP-1 medication. 2
Many diabetes patients who take GLP-1 medications lose a smaller amount of weight than patients who take GLP-1 medications and do not have diabetes. There can be many reasons for this: They may take other medications that can cause weight gain, they may have altered microbiota bacteria affecting their digestive system or they may have a genetic background that causes it to be harder to lose weight. Also, some diabetes patients may not exercise regularly and have had obesity for a longer period of time, making their body predisposed to it.
Key Considerations Moving Forward
- Long-Term Studies: While short-term data on semaglutide drugs and weight loss is promising, the long-term effects on cardiac muscle, especially in those with heart disease, are still unknown. Ongoing trials and real-world data are critical to understanding these potential risks better.
- Targeted Screening: For patients with existing heart disease, close monitoring of cardiac function, muscle mass (through imaging or biomarkers) and other metabolic parameters has become increasingly important as the use of semaglutide and related drugs becomes more widespread.
- Individualized Treatment: For patients with significant cardiovascular disease or heart failure, the decision to use Ozempic-like drugs must be individualized, weighing the benefits of glycemic control and weight loss against the potential risks, including muscle loss and any unknown cardiovascular effects. Consider consulting a cardiologist to discuss these in detail with you.
While the possibility of muscle loss in the heart with Ozempic-like drugs is an important consideration, the current data does not conclusively support this hypothesis. However, given the increasing use of these medications in clinical practice, particularly for weight loss for people who do not have diabetes, we must remain vigilant about potential unintended consequences. As with all medications, especially those affecting complex systems like metabolism and cardiovascular function, further research is needed to fully understand the benefits and risks, including any effects on the heart muscle.
I Want to Lose Weight. What Can I Do to Combat Muscle Loss?
If you are taking Ozempic or a similar weight-loss drug, or if you plan on losing weight, it is important to exercise and eat a nutritious diet with an emphasis on high protein to combat muscle loss.
According to the Dietary Guidelines for Americans 2020-2025, women need to eat 46 or more grams of protein daily and men need to eat 56 or more grams of protein daily. However, if you eat more calories per day or if you do muscle-building workouts, you may need more protein each day. If you do not get enough protein in your diet, it may be helpful for you to use protein powder or consume protein shakes.
When exercising, you can build muscle by using resistance bands or lifting weights. Muscle-building workouts strengthen your muscles and reduce the risk of muscles shrinking during weight loss.
UofL Health is Here for You
If you are thinking about taking Ozempic or another weight-loss drug, it is best to discuss it with your primary care provider. Your provider can also help you develop and stick to a nutrition and exercise plan that works best for you. If you need a provider, call UofL Physicians – Primary Care at 502-588-4343 to schedule an appointment.
If you have one or more risk factors that might increase your chances of a first heart attack or have previously suffered from cardiovascular disease, our preventative cardiology experts at UofL Physicians – Cardiology and UofL Physicians – Cardiology Associates can help improve your quality of life and prevent future cardiovascular problems. Call 502-588-7010 today to schedule a consultation or visit one of our heart care locations to find a cardiologist close to you.
1 Kramer, C, Borlaug, B, Zile, M. et al. Tirzepatide Reduces LV Mass and Paracardiac Adipose Tissue in Obesity-Related Heart Failure: SUMMIT CMR Substudy. JACC. null2024, 0 (0) . https://doi.org/10.1016/j.jacc.2024.11.001
2 Jensterle M, Rizzo M, Haluzík M, Janež A. Efficacy of GLP-1 RA Approved for Weight Management in Patients With or Without Diabetes: A Narrative Review. Adv Ther. 2022;39(6):2452-2467. doi:10.1007/s12325-022-02153-x
