Alumni perspective: Examining GLP-1s through a public health lens
New “weight loss drugs” can be an important tool for improving personal and population health
As a cardiologist focused on preventing heart disease, I’m often asked about the new class of drugs known as GLP-1. These are the medications with brand names like Wegovy and Zepbound that are widely seen as “weight loss drugs.”
Skeptics have raised several important critiques of these drugs, including their cost, their potential side effects, and the growing trend of using them for “cosmetic” weight loss. There’s also concern that they are being used as a substitute for the age-old prescription of a healthy lifestyle, including nutritious food and regular exercise.
I take a public health approach to these issues — and, as a result, I firmly support using these medications as indicated. In my clinical experience, and based on my reading of the scientific literature and my understanding of public health data, these therapies have the potential to make people healthier. And that’s an outcome that we all should welcome.
Many factors underlie the obesity epidemic
In 1975, fewer than 1 in 10 Americans was living with obesity. Today, approximately 1 in 3 Americans have this condition.
While an increase in caloric intake and a decrease in physical activity have clearly played a role in this epidemic, these are not issues that individuals can solve with pure willpower. Societal changes such as the increased availability and low cost of ultra-processed foods as well as the decreased availability and expense of healthy nutrition have clearly contributed to the obesity epidemic. Unfortunately, low-income families and members of minority communities tend to be disproportionally affected. Similarly, changes to our communities and workplaces have discouraged routine physical activity.
We also see changes at the level of our DNA: The field of epigenetics has shown that, for various and complicated reasons, genes associated with increased metabolism are being suppressed by our current environment, while genes that inhibit metabolism are being activated. This can make it harder for individuals to burn calories at rates that inhibit weight gain.
So, while a healthy lifestyle is the foundation of cardiovascular health, simply encouraging people to eat less and move more will be inadequate to combat the obesity epidemic. Additional interventions are needed across the spectrum of population health, including policy changes, educational programs, and individual treatments — including these new weight loss medications.
The rise of GLP-1 therapeutics
Glucagon-like peptide-1 (GLP-1) is a hormone that stimulates multiple actions throughout the body. Probably most importantly, it slows gastric emptying. That means the stomach takes longer to process a meal, leading individuals to feel full despite eating less.
Medications that stimulate GLP-1 were initially developed to lower blood sugars for treatment of diabetes, and they are quite effective for this condition. However, over time, further research showed that these medications also produced significant weight loss, including in individuals without diabetes. With this weight loss subsequently comes improvements in blood pressure, triglycerides, and other cardiovascular risk factors, as well as quality of life.
Quite frankly put, these medications make people healthier.
In 2018, the landmark SELECT trial showed that use of semaglutide (brand names Wegovy or Ozempic) in individuals with cardiovascular disease but without diabetes not only improved cardiovascular risk factors but also decreased rates of heart attack and stroke, as well as death from any cause. We have few preventive interventions that have been shown to have this significant an impact on cardiovascular health.
I’ll note here that I do not receive any funding from the pharmaceutical industry — and neither does the program I direct at the Minneapolis Heart Institute.
Addressing the concerns about GLP-1 drugs
Concerns about the rising use of GLP-1s have come from both the lay public and the healthcare community.
One cluster of concerns focuses on potential side effects. It’s important to note that these medications have been in use for well over a decade for treatment of diabetes, with an excellent safety profile. Because they slow gastric emptying, these medications can cause gastrointestinal (GI) side effects, such as abdominal pain, nausea, and vomiting. But in my clinical practice, I have seen that when the medications are started at a low dose and slowly increased over time, most individuals tolerate them quite well. That’s the case for more than 90% of our patients who start a GLP-1 medication.
Another area of concern is the cost. This is a serious issue: The average list price for these drugs is about $12,000 a year, and many large insurers restrict coverage.
But looking at this issue from a public health lens, it’s important to recognize that obesity has an enormous cost — estimated at more tha $1 trillion a year in the U.S. due to increased healthcare costs and loss of productivity. Given the cardiovascular health benefits seen in the relatively short-term trials to date, there is potential for the GLP-1’s to be cost-effective on a societal level.
As more drugs in this class come on the market, I also expect and hope that costs for individual patients will come down.
Understanding the stigma of obesity
As a preventive cardiologist, I’ve found that the most frustrating aspect of trying to get these medications to the right patients is the stigma of obesity.
Most providers and patients accept that cholesterol and blood pressure both have strong genetic components and thus understand that pharmacologic treatment is sometimes needed, regardless of how well an individual eats and exercises.
Yet that understanding too often breaks down when it comes to obesity. Even some healthcare providers complain that these medications are a being used as a substitute for a healthy lifestyle, implying that if the patient took better care of themselves, they wouldn’t need a GLP-1. That simply isn’t the case.
These medications are by no means a substitute for a healthy lifestyle; on the contrary, they are most effective when combined with one.
A heart-healthy nutrition pattern and lots of physical activity are, and will always be, the foundation of cardiovascular health — but obesity, just like other cardiovascular risk factors, has strong genetic and environmental components. I have many patients that take really good care of themselves but still struggle with obesity and either have, or are at elevated risk for, cardiovascular disease.
In that setting, if we have an intervention that clearly helps, that is safe and effective, and that is supported by the science, what’s wrong with trying to make those patients healthier?
Michael D. Miedema, MD, MPH ‘13, is director of cardiovascular prevention at the Minneapolis Heart Institute. He was honored with Harvard Chan School’s Emerging Public Health Professional Award in 2023.
