WASHINGTON — The drug tirzepatide — sold under the brand names Zepbound for obesity and Mounjaro for diabetes — significantly lowered the blood pressure of adults with overweight or obesity who took it for nine months, according to a new study.
This research, published Monday in the American Heart Association journal Hypertension, is part of a larger clinical trial that previously showed that weekly tirzepatide injections resulted in weight loss of up to 22% in adults with overweight or obesity, helping prompt the US Food and Drug Administration to approve the drug for chronic weight management in November. The research was funded by the drug’s maker, Eli Lilly.
To assess the effect of tirzepatide on blood pressure, the researchers enrolled 600 adults from the original clinical trial who had a body mass index of 27 or more, who did not have type 2 diabetes and who had either normal blood pressure or high blood pressure that was under control. The participants had their blood pressure monitored for a day before beginning treatment and again after nine months of weekly tirzepatide injections.
The results showed a significant decrease in the participants’ systolic blood pressure, the top number in blood pressure readings, which is a strong predictor of heart disease.
Participants taking 5 milligrams of tirzepatide weekly had an average reduction in systolic blood pressure of 7.4 mmHg, those on 10 milligrams had an average reduction of 10.6 mmHg, and those on 15 milligrams had an average reduction of 8.0 mmHg.
“An eight-point difference is really an impressive effect that rivals or exceeds many of our usual blood pressure medications,” said Dr. Harlan Krumholz, a cardiologist at Yale University who was not involved with the research.
The real effect of tirzepatide on blood pressure may be even more pronounced, given that most of the study participants did not have high blood pressure to begin with, said Dr. Michael E. Hall, chair of the Department of Medicine at the University of Mississippi Medical Center, who was not involved with this study.
Tirzepatide works by mimicking the action of two different gut hormones. When blood sugar rises after eating, the drug stimulates the body to produce more insulin, which lowers blood sugar. It also slows the movement of food from the stomach, making people feel fuller for longer. It works similarly to semaglutide, the active compound in the weight loss drug Wegovy and its sister diabetes drug, Ozempic. Wegovy was shown to reduce the risk of heart attack, stroke or heart-related death in people who had heart disease and obesity or overweight by 20% in astudy last summer.
As for the new study, it’s not clear whether the significant reduction in blood pressure was due to the participants’ weight loss in the larger study or the medication. The study also did not account for participants’ dietary intake, which could play a role in the results.
Additional studies will be needed to determine tirzepatide’s effect on direct cardiovascular conditions like heart attack and heart failure and to assess whether the blood pressure changes reverse after people stop taking the drug, said Hall, who also chaired the writing group for the American Heart Association’s 2021 scientific statement on weight loss and hypertension, in a news release.
“Overall, these data are encouraging that novel weight-loss medications are effective at reducing body weight and they are also effective at improving many of the cardiometabolic complications of obesity including hypertension, Type 2 diabetes and dyslipidemia, among others,” he said.
More than 47% of adults in the United States have hypertension, defined as blood pressure over 140/90 mmHg, and nearly 42% of adults have obesity, according to the AHA’s 2024 Heart Disease and Stroke Statistics. These diseases are closely linked, as obesity is the main cause of high blood pressure; about 75% of hypertension can be attributed to obesity, according to the American Heart Association. And high blood pressure is a major risk factor for heart diseases like coronary artery disease and stroke.
“By treating one disease, obesity, we can potentially mitigate hundreds of other obesity-related conditions, including hypertension,” Dr. Ania Jastreboff, director of the Yale Obesity Research Center, who helped conduct the larger weight loss trial, wrote in an email.
Although there are effective blood pressure medications available, only about a quarter of people with hypertension have adequately controlled blood pressure, Hall said. This is often because people don’t take their medications. Finding a way to simplify and combine treatment for these diseases would make life much easier for both patients and doctors, Hall added.
Krumholz said that although much of the hype around tirzepatide has focused on its weight loss effects, the real health benefits lie downstream: weight loss leading to reduced blood pressure and increased ability to exercise, leading to improved heart health. He views the weight loss effect of the drug as a pleasant side effect that will make people more likely to take their medication.
Before the development of tirzepatide and similar obesity drugs, lifestyle modifications were the main way to treat obesity, Krumholz said. Though these are also beneficial, a healthy diet and more exercise often aren’t enough to combat the disease of obesity and our bodies’ evolutionary tendency to try to regain weight, he added.
“Patients would end up feeling bad about themselves and frustrated and guilty,” he said. “These [drugs] represent almost a miracle. [People] can now take a medication that not only helps them lose weight but can improve their health.”
However, the cost of these new weight loss medications and insufficient insurance coverage keeps many eligible people from accessing them, Krumholz said. He warned that unless these barriers are addressed, these new treatments could instead contribute to worsening health disparities in the US.
