By Dr. Asnat Raziel, bariatric surgeon specializing in obesity treatment, metabolic health and healthy longevity; Director of the Multidisciplinary Center for Obesity Treatment, Assia Medical, Assuta Ramat HaChayal, Tel Aviv
Heart age after bariatric surgery: what the researchers found
Biological heart age may decline modestly after metabolic and bariatric surgery. That is the finding of a new study by Mayo Clinic researchers, who estimated heart age with an AI analysis of the ECG. However, the change appeared mainly in the long term, and it was not large. In addition, weight loss alone did not explain it.
The journal Obesity Surgery published the study in September 2026. It brings together three fields: obesity, metabolic surgery, and artificial intelligence that tries to estimate the pace of aging.
What is ECG-based heart age?
Chronological age is the number of years since you were born. Biological age, by contrast, tries to estimate whether the body’s systems work like those of a younger or an older body. I explain the difference between the two in my article on biological age and longevity.
In this study, the researchers used an artificial intelligence algorithm. The algorithm, developed at Mayo Clinic, analyzes a standard 12-lead ECG, meaning 12 recording points. It detects subtle electrical patterns and uses them to estimate “ECG age.” Next, the researchers calculate the age gap: ECG age minus chronological age. For example, if a 50-year-old patient gets an ECG age of 56, her gap is six years.
A positive gap may hint at accelerated aging of the heart. On the other hand, a gap of zero or less reflects a heart that matches its chronological age or is younger.
What we know about this heart age marker
A systematic review and meta-analysis of 17 studies looked at this age gap. A larger gap went hand in hand with high blood pressure, diabetes and heart disease. It was also linked to a 1.62-fold higher risk of death from any cause, and a 2.12-fold higher risk of cardiovascular death. Even so, this is a research marker that is still evolving. It is not a stand-alone clinical test.
How the study was designed
This is a retrospective cohort study, meaning the researchers looked back at existing data. They examined 2,380 adults who had a first metabolic and bariatric operation between 2008 and 2023. In total, the team analyzed 6,149 ECGs, recorded before surgery and during follow-up.
The statistical models separated two kinds of relationships. The first is the difference in weight between different patients. The second is the change in weight within the same patient over time. This distinction matters. People with higher weight do show an older ECG age. Still, that does not prove that losing a few kilograms will promptly lower ECG age.
Before surgery: the heart looked almost four years older
Before surgery, the median age gap was 3.86 years. In other words, the algorithm estimated that the typical patient’s heart was almost four years older than their actual age. Moreover, 69.6% of participants had a positive gap at the start of the study.
This finding fits what we know about obesity as a whole-body disease. Chronic obesity is linked to insulin resistance, inflammation and high blood pressure. It is also linked to sleep apnea, fatty liver and extra strain on the heart. All of these may show up in the electrical patterns the algorithm detects.
Heart age in the years after bariatric surgery
In the first year after surgery, there was no significant drop in the gap. In fact, the model showed a change of +0.275 years per year, but the result was not statistically significant. After the first year, the picture changed. The age gap fell by an average of 0.192 years for each year of follow-up, and this result was significant.
This is a very modest improvement: about a fifth of a year per year. So it would be wrong to say that surgery quickly “erases years” from heart age. The accurate reading is a small trend of slowing, or partial reversal, over time. Also, the model that split follow-up into two periods was not significantly better than a simple straight-line model. Therefore, we should read the distinction between the first year and later years with caution.
In about one in five patients, the gap disappeared
The study included 1,657 participants who started with an ECG age higher than their real age. Of these, 335 reached a gap of zero or less on at least one ECG. That is a rate of 20.2%. This is an encouraging figure. However, it does not necessarily indicate a lasting change, because the result may not have repeated on later tests.
Heart age and long-term excess weight
One of the most interesting findings concerned prolonged exposure to high weight. When comparing different people, every 10 kilograms of average weight went along with a gap that was 0.548 years larger. Baseline BMI, the lowest BMI after surgery and the maximum BMI were also linked to a larger gap.
By contrast, a 10-kilogram change within the same person was not significantly linked to a change in the gap. Likewise, the percentage of excess weight lost and weight regain were not related to the marker. In other words, people who lived for years with severe obesity tended to have an “older” heart. But the study did not show that the number of kilograms lost was what drove the change.
Where could an improvement not explained by weight come from?
Metabolic and bariatric surgery affects many body systems, beyond the number on the scale. After surgery, blood sugar control and insulin sensitivity usually improve. In addition, blood pressure and inflammation in the body go down. Gut hormones also change, deep belly fat shrinks and sleep apnea improves. Some of these changes begin even before full weight loss is reached.
Support for this also comes from a Polish study of 40 patients who completed two years of follow-up. After surgery, aging markers such as telomere length, DNA damage and measures of inflammation improved. This improvement appeared even in patients who lost less weight than the target. That said, there may be other explanations as well. Perhaps the marker is not sensitive to short-term changes, or perhaps the heart improves with a delay.
Bariatric surgery and long-term health
Metabolic and bariatric surgery has a far broader research base than biological age markers do. A BMJ review of long-term outcomes describes major, lasting weight loss and improvement in type 2 diabetes. It also describes fewer cardiac events, less cancer and lower mortality. The Swedish Obese Subjects study found that people who had surgery lived 3.0 years longer than the control group. So the new study does not reveal a new clinical benefit. Rather, it adds a research tool for understanding how surgery affects the heart.
Limitations of the study
First, this is a retrospective study, not a randomized controlled trial. Second, it had no control group of people with obesity who did not have surgery. In addition, the ECGs were done as part of routine care, so their timing was not uniform. Finally, a drop in the marker does not guarantee fewer cardiac events. AI-based ECG age is a research marker, not a precise clock of heart age.
What can we learn about heart age?
This study strengthens the understanding that obesity is not just excess weight. It is a chronic condition that may speed up the aging of the body’s systems. I discuss this link further in my article on obesity and heart disease. Even so, these findings do not justify surgery in order to “make the heart younger.” The decision to have surgery rests on the severity of obesity, related conditions and previous treatments. It requires professional evaluation, preparation and multidisciplinary follow-up, and sometimes there are alternatives to bariatric surgery. If you are weighing your options, you are welcome to contact my clinic.
The bottom line on heart age and bariatric surgery
In a study of 2,380 patients, AI-ECG heart age before surgery was almost four years older than actual age. After surgery, a modest long-term decline in the gap appeared. However, the improvement was neither fast nor large, and weight loss did not directly explain it. This is an encouraging finding, but it is not yet proof that surgery turns back the clock. The broader message is especially important: metabolic health, heart function, fitness, muscle mass and sleep are all essential parts of obesity treatment.
The information in this article is general and is not a substitute for personal medical advice.
References
Age and Sex Estimation Using Artificial Intelligence From Standard 12-Lead ECGs
Long term outcomes of metabolic/bariatric surgery in adults
Life Expectancy after Bariatric Surgery in the Swedish Obese Subjects Study
The researchers declared no conflicts of interest.
