Obesity is one of the main causes of high blood pressure, also known as hypertension. We've known there is a connection for years, but the link between the two has not been well understood – until now.
In 2019, my colleagues and I made the surprising discovery that changes to sugar molecules in the body could be the missing link – and that a dietary supplement could potentially help reduce the risk of patients with obesity developing high blood pressure.
One in three U.S. adults have high blood pressure, according to the Centers of Disease Control and Prevention (CDC). Meanwhile, the CDC says nearly 40% of U.S. adults are obese – defined as having a body mass index (BMI) of more than 30.
These are serious conditions. Both increase the risk of heart disease and stroke. Obesity also raises the risk of diabetes, cancer, and other life-threatening illnesses. If we could offer patients a supplement that – when paired with healthy lifestyle choices – could reduce their risk of hypertension, it could be similar to offering patients a second chance at a longer, healthier life.
While more research is needed before we can use our study findings in a clinical setting, we're making strides with ongoing research. Let’s take a look at what this study found, our next steps, and what patients can do right now to reduce their risks.
Sugar chains and the missing link
In our research, we fed laboratory mice a high-calorie, high-fat diet to make them obese. As expected, the mice developed hypertension.
But what we didn’t expect to find was a change in the structure of their immunoglobulin G, or IgG, which is the most common type of antibody found in the circulation. Specifically, we found a change in a series of sugar molecules that bind to IgG.
The study showed that the amount of a sugar known as sialic acid on the chain of sugars attached to IgG falls as obesity increases. And as the sialic acid abundance on the chain dropped, blood pressure went up. These changes were not seen in lean mice that were fed a typical diet.
We determined that the changes in the IgG sugar chain have detrimental effects on the cells that make up the lining of blood vessels. These cells are part of the body’s mechanisms that regulate blood pressure.
But what about humans?
We partnered with Gordan Lauc, Ph.D., a world-renowned scientist in Croatia who studies these sugar chains. We wanted to know whether we could find evidence that this same structural change occurs in humans.
We conducted a study in 3,400 volunteers that confirmed that the IgG sugar chain changes observed with obesity in mice do, in fact, occur in people. These changes are associated with an increase in a person’s systolic blood pressure, the top number you see in a blood pressure reading. We also learned that sugar chain structure changes also occur as we age, potentially making older patients more susceptible to high blood pressure.
Related reading: How blood pressure affects heart disease risk
From discovery to prevention
From there, we began to think about how we could use this knowledge to prevent these structural changes from happening, and potentially prevent high blood pressure in our lab mice.
We fed another set of mice an obesity-inducing diet, but this time we added to their drinking water a naturally occurring chemical known as ManNAc that is made during the body’s production of sialic acid. ManNAc is already being studied in patients with hereditary inclusion body myopathy (HIBM), a rare genetic disease that causes reduced sialic acid production.
Our research showed that mice who took the supplement did not develop high blood pressure. Their sugar chain structure remained normal, even though they continued to be obese. What's more, we have data indicating that the supplement might also help prevent the development of diabetes – another major risk factor for heart disease.
Potential next steps
This preliminary information is encouraging and we are working toward the next phase of research, which will be to design a pilot study to determine whether such a supplement could prevent high blood pressure and possibly also early signs of diabetes in volunteers briefly given a high-calorie, high-fat diet.
There is still a lot of work to be done in the field of obesity prevention and care. And we're excited to have an opportunity to potentially help a high volume of patients avoid the hypertension that often complicates obesity.
That said, it’s important to reinforce that the dietary supplement used in this study did not cause the mice to lose weight. It served as more of a protective agent against damage but does not address the overarching concern. This is similar to how cholesterol medication can stave off plaque buildup, to a point, even if a patient does not reduce their cholesterol intake.
Related reading: 10 truths about statins and cholesterol
Lifestyle choices matter, and obesity is a tough condition to turn around. In fact, recent research has shown that obesity is associated with reductions in brain tissue volume and functionality, which can make it difficult to lose weight.
If you are currently obese or are concerned about your weight, talk to your doctor about personalized options to lower your risks. These might include:
- Support and resources to improve your nutrition, exercise more and more effectively, and quit smoking
- Medications to help with weight loss
- Bariatric surgery for weight loss
For blood pressure concerns, consider making small changes in partnership with your doctor to achieve a healthy blood pressure. Your doctor might also recommend taking blood pressure medication and monitoring your blood pressure at home to capture an accurate reflection of your daily numbers.
Researchers and public health officials around the world are uniting to combat the growing obesity epidemic. My colleagues and I at UT Southwestern are focused on preventing some of the severe complications of obesity.
Ultimately, we hope our findings will help break the link between obesity and high blood pressure, giving patients one less thing to worry about as they work to improve their health.