WINSTON-SALEM, N.C. – April 27, 2022 – For years, patients struggling with obesity have been told that their weight is solely the result of bad choices and that they need to eat less and move more. Sounds simple, but weight loss isn’t a simple matter. While lifestyle changes are the first-line approach in the treatment of obesity, up to half of patients are not successful in losing weight with dietary changes and increased exercise alone. And the majority of patients who do find success with lifestyle changes typically regain lost weight within two years.
“Obesity is a chronic disease,” said Dr. Kristina Henderson Lewis , associate professor of epidemiology and prevention at Wake Forest University School of Medicine. “As our understanding of physiology has changed, we’re learning that there are complex processes in our body that are actively opposing weight loss, so it’s not surprising that many people have a hard time keeping weight off in the long-term with just lifestyle changes.”
Obesity affects more than 40% of U.S. adults and despite the availability of anti-obesity medicines, they are rarely prescribed because they are expensive and not frequently covered by insurance.
One low-cost alternative is the anti-obesity medicine phentermine, but it’s only approved for short-term use (up to 12 weeks).
“A common concern with phentermine is that it may lead to increases in blood pressure and heart rate for some patients, potentially increasing the risk of cardiovascular disease, though this might be offset by the cardiovascular benefits of losing weight. There’s very little research on the long-term effects of phentermine," Lewis said.
But now, with the support of a $1.7 million grant from the National Institutes of Health, researchers at the School of Medicine will lead the Long-term Effectiveness of the Anti-Obesity medication Phentermine (LEAP) trial, a placebo-controlled, randomized controlled trial that will enroll 1,000 adults at five sites across the U.S. The clinical coordinating center and data coordinating center for the LEAP trial are both housed at the School of Medicine and is co-led by Lewis along with Dr. Jamy Ard , professor of epidemiology and prevention, and Nicholas Pajewski , associate professor of biostatistics and data science.
“The trial is designed to help us gain a better understanding of the effects of phentermine not only on weight, but also changes in blood pressure, heart rate, blood sugar and cholesterol levels,” Lewis said.
Patients will be followed for two years. One group of participants will receive 24 mg/day of phentermine, and one group will receive a placebo for up to 24 months. All participants will be provided with an evidence-based online lifestyle intervention to support changes to their diet and exercise habits.
“The obesity epidemic isn’t going away, and we desperately need long-term treatment options,” Lewis said. “This trial will tell us whether or not low-cost phentermine is an option that could help some patients with weight management.”
Collaborating institutions include Johns Hopkins University, the University of Texas Health Science Center at Houston, Kaiser Permanente Southern California and HealthPartners Institute.