The Long-term Impact of Bariatric Surgery in Adolescents with Thomas Inge, MD, PhD

Erin Spain: [00:00:10] This is Breakthroughs, a podcast from Northwestern University, Feinberg School of Medicine. I'm Erin Spain, host of the show. As the obesity epidemic continues to impact more children and teens, bariatric surgery is proving to be an effective tool to help them lose weight and reverse the progression of weight related conditions such as type two diabetes. That's according to research conducted by today's guest, Dr. Thomas Inge, who leads the Teen Longitudinal Assessment of Bariatric Surgery study, the only multicenter NIH sponsored research on adolescent bariatric surgery. He is the chief of pediatric surgery and the Department of Surgery at Feinberg and the surgeon in chief at the Ann and Robert H. Lurie Children's Hospital of Chicago. He joins me to talk about his research and the long term impact bariatric surgery can have on young patients. Welcome to the show.  

Thomas Inge, MD, PhD: [00:01:09] Well, thanks for having me Erin, I really appreciate the opportunity to talk to you guys today about what I've been up to for the last 20 years.  

Erin Spain: [00:01:16] Let's talk broadly about obesity in America, especially childhood obesity. The number of obese children in America has been trending upwards since the late 1970s. Explain what has happened over the past 40 years with obesity in America and how it's impacting children.  

Thomas Inge, MD, PhD: [00:01:34] Well, that's certainly a big question, Erin. The last 40 years has seen a lot of technological innovation. It's seen a lot of changes in the way our society really interacts, and it's seen changes in our food environment. Some people have called it the toxic food environment these days. You know, since the introduction of high fructose corn syrup decades ago and the correlations that have been drawn to specific things like this in the processed foods, we certainly have some research now that is pointing directly at the harms that processed foods compared to natural foods, things that come in packages versus that come from the produce section provide in terms of hazards for weight gain. I think you couple changes in the food environment with changes in opportunities for safe, vigorous play outside, especially as we consider some of the population centers that are really quite dense. And those opportunities are certainly fewer than there were decades ago. So I think all of these environmental food built environment factors do weigh heavily on the risks for excess weight gain that we've seen in kids in particular.  

Erin Spain: [00:02:42] And there just doesn't seem to be any sign of this slowing down. Is that right?  

Thomas Inge, MD, PhD: [00:02:47] Well, we've got a lot of focus by professional societies, by the government, by nonprofits on these problems. But despite all of the focus from all the different sectors, we are still seeing, you know, pretty concerning rates of obesity. And gosh, you just consider this last few years with the COVID epidemic. Some of the early findings that are just now coming to light for the ramp up or the acceleration in weight gain, particularly in the younger age groups, is frightening. And that certainly is being directly linked to the kind of things that we know are bad for you. That screen time increased during the COVID epidemic, the opportunities for group play and purely being with your friends and, you know, doing organized athletic activities really tanked during the epidemic. And we see that unfortunately in aggressive weight gain in our kids.  

Erin Spain: [00:03:43] Yeah, those latest studies have said as about 20% of American children are now qualified as being obese. 

Thomas Inge, MD, PhD: [00:03:49] Yeah, that's right. That number has steadily risen over the decades. And, you know, the micro epidemic, if you will, within that obesity epidemic is what we focus on. And that's severe obesity. So, again, a micro epidemic of those that are, you know, really 75 to 100 pounds overweight. And how that group has really increased in proportion over the decades is really very concerning, because that's the group that unfortunately bears the greatest burden of health problems associated with that extra weight.  

Erin Spain: [00:04:22] Tell me about those health problems. How does severe obesity impact their quality of life and their life span? 

Thomas Inge, MD, PhD: [00:04:28] As a surgeon you know, we do tend to medicalize things. And so we look at metabolic health, we look at things like type two diabetes and pre-diabetes. We look at the antecedents of heart disease. And those are dyslipidemia and, you know, some stiffening of the arteries, hypertension, that kind of thing. Those things are certainly more prevalent in the patients with obesity and particularly severe obesity. But we also see liver disease, fatty liver disease and even fibrosis. We see obstructive sleep apnea and its many manifestations that are unhealthy for the individuals, including things like doing more poorly in school because you're not sleeping well at night. And so those are the chief medical issues. But then, you know, as you mentioned, quality of life. We've studied this actually and found pretty deplorable impairments in quality of life. That's weight related for the kids that are gaining all of this excess weight. In fact, the data, when we used instruments that are comparable, we find that kids that have been studied that have cancer report actually comparable levels of a low quality of life as obese kids. And so it really hits home. What, you know, this epidemic of obesity is not only having real physical health effects, but it's also having just enormous effects on their development and the way kids relate to one another. And that quality of life is so important to just attain normal developmental milestones in especially teenage years.  

Erin Spain: [00:06:03] There are very few treatments for severe obesity, but bariatric surgery is a treatment, and your work in bariatric surgery in children and teens has really helped the procedure gain acceptance in the medical community. What sort of experience has a child in their family typically had before they end up speaking with you and having a consultation about bariatric surgery?  

Thomas Inge, MD, PhD: [00:06:25] The lived experience of these teenagers and families with severe obesity is very different than most of us can can comprehend, especially when we think that, you know, some of these teenagers are coming to these treatment at, say, 300 or 400, even 500 pounds. And so what they can't do during their, you know, normal childhood is really pretty eye opening. They can't wear clothes that would be considered normal for their age, for instance. They can't sit around with their friends and participate in sports or participate even in, you know, most of the things that teenagers want to do on a day to day basis. They don't sleep well at night. Some of them sleep sitting up in a reclining chair just because of their poor sleep quality. When they try to lie flat, they're in the doctor's office more for treatment of their co-morbidities and again, their quality of life, just from the standpoint of, you know, what we would consider their normal right of of a any student body to get into a desk without feeling like it's constricting is taken away from them. So I think a lot of their childhood is taken away from them. And, you know, on a personal level, when I was training for these operations and really developing a program, we visited a number of the better programs in the country. And we would talk to the office staff. And the office staff, it turns out, are often, you know, patients themselves. And what they would tell us is we so much cheerlead your efforts at doing this and setting up programs for teenagers because you can't go back to high school. And that was their message that they had the surgery when they were adults. But the experience that they had going through those younger years in high school in particular can be very painful. And that's that was their message. You know, you can't go back to high school. What you're doing is giving them a new lease on life and those formative years when it really matters.  

Erin Spain: [00:08:24] Tell me about the initial resistance and doing the surgery on teens. Back when you started.  

Thomas Inge, MD, PhD: [00:08:30] When I got out of my pediatric surgery fellowship in 2000 and started my job, my first job at Cincinnati Children's, we really didn't think about surgery for obesity in teenagers, but there was a lot of evidence in the adult experience that surgery could be very helpful for weight, as well as the weight related health complications. And so we started thinking more about this when we had patients that were developing such severe weight problems that they developed severe sleep apnea problems and diabetes. And we really didn't think that it was fair to turn a blind eye to the potentially, you know, quite beneficial therapy, surgical therapy that is. So despite the fact that there was no treatment paradigm at the time or any guidelines that, you know, really talked about treatment of teenagers, we took it as our mission to have this group of people, these teens that were developing awful complications, health complications. We took it as our mission to really see, well, what would it take? What could a freestanding children's hospital do about that? And pulled together people from all walks of life in the hospital that is on the pediatric side, the subspecialty side, G.I., Pulmonary, Endocrine, Dietary, Nursing and we pulled them together with some ethicists as well to say, can we do this? Can we do it safely and should we do it? How do we do it? And ended up with putting together, I think, a multidisciplinary treatment program that did seem to fit the bill. And initial patients that came through really, I think, provided a great deal of optimism for everyone involved that we were doing the right thing and that we were doing it for the right reasons.  

Erin Spain: [00:10:13] And out of that was born. The Teen Longitudinal Assessment of Bariatric Surgery Study. You're an outcomes researcher, right? So this was a natural sort of progression for you to study this group.  

Thomas Inge, MD, PhD: [00:10:25] Yeah, that's that's right. I mean, I think whenever we are doing anything innovative in pediatric healthcare or health care in general, in many ways we owe it to ourselves and our patients and the future patients to really build research programs around those novel interventions to be able to inform us of, you know, what are we doing right? What are we doing wrong? What can patients expect in terms of outcomes? We did some, you know, some smaller single institution studies and looked at our data. And with that, you know, is the well-worn path to going to the NIH for funding. You really have to go with some preliminary findings. And so we made our pitch to NIH in the form of a grant application to do a multicenter study and a much longer longitudinal study than we could fund with local resources. And so they were intrigued with the overall hypothesis in terms of the way that we thought we would add the most to the literature would be to ask the question, does operating earlier in the, you know, life course of severe obesity rather than waiting until later make more sense and by the make more sense you know the apotheosis was that we would more readily turn around these medical complications of severe obesity by operating earlier than the experience in adults. So operating on teenagers and looking at their resolution or the impact on diabetes or other complications of obesity, and again, predicting that the impact would be greater for youth than older individuals was. I think what got the attention of the reviewers and led to us being funded back, like you said, in 2006.  

Erin Spain: [00:12:03] Well, let's talk about some of the findings. You were the author of a paper published in the New England Journal of Medicine called Five Year Outcomes of Gastric Bypass in Adolescence As Compared with Adults. So what were the findings of this paper and how do kids and adults outcomes compare? 

Thomas Inge, MD, PhD: [00:12:20] Again, that was the centerpiece hypothesis of the study that we were looking at. So what we did was we collaborated with another study that was an ongoing NIH funded cohort study called Labs are Longitudinal Assessment of Bariatric Surgery. So we were very clever in our naming of our study, of course, teen labs. Right. But nonetheless, we did borrow methodology so that we could really line up these investigations and compare fairly, you know, the outcome of teenagers to adults. And what we found is that for those adults undergoing these procedures, they actually had identical weight loss. So the weight loss for the teens in the adults over this five year journey was the same. There's always a precipitous drop in weight after the operation, and you see about 30% weight loss over that first year. And then they tend to level out, maybe regain a little bit of weight over that period of time. But those curves were identical. And so that was very reassuring that the operations are, you know, doing the same in terms of energy balance and and, you know, the adipose tissue burn, if you will. But the key questions, though, to test the hypothesis had to do with, well, what happened to the co-morbidities, what happened to type two diabetes, and was there a differential that we can expect? And again, what we found, though, was that we saw greater resolution in the type two diabetes, as well as hypertension when we studied the teens versus the adults and the magnitude of that. So if we're looking at the remission rates, for instance, both groups for type two diabetes had a good remission at one year, let's call it, you know, between 60 and 80% remission, which is very good. But the staying power of that remission was greater in the teenagers. In fact, when we looked at one year, it was about 80% in the teenagers and it was about 85% still in remission at five years. For the adults, their one year remission was about 60%, and that had fallen to about 50% at the five year mark. So at five years, 50% versus 85% to actually statistically significant difference. And it's different from a clinical standpoint, too. So we know that type two diabetes, you know, requires medication use and sometimes injectable medication. But it's also really a terrible problem for your other systems, including the kidney, putting blood vessels, including your retina. These things are all comorbidities of type two diabetes. And so we anticipate that the teenagers will have fewer disabilities related to diabetes, you know, at 15, 20, 25 years down the road because they had the surgery and because they had this early remission. But that's not the end of the good news. We also studied, like I said, blood pressure in these individuals. We had about 240 or so teenagers altogether, and we compared them to about 400 adults. And what we found was that it was similar to the story with type two diabetes. They actually had greater remission of their hypertension at five years. So the teenagers who are still showing us about 70% remission of their high blood pressure at five years, whereas the adults were down, more in the like 45%, range in remission. So, you know, high blood pressure in kids is another problem that is believed to lead to a number of health issues later in life, be it, you know, congestive heart failure or other forms of cardiovascular disease and kidney disease as well. So we believe that these findings, again, would indicate that they have a healthier future ahead of them. And that's really what we were looking for.  

Erin Spain: [00:16:00] There are some risk factors involved with undergoing bariatric surgery and these young people. What did you find are the risk factors?  

Thomas Inge, MD, PhD: [00:16:08] So we had three deaths in the adolescent cohort and seven deaths in the adult cohort. The rate was really the same. When we looked at intra abdominal operations, we did find that there was a difference there, a higher rate of intra abdominal operations within five years in the teenagers compared to the adults. And so what might that be related to? You know, were the procedures more risky for some reason than the teenagers? Well, I will say that the teenagers had a higher BMI at baseline. And we know that higher BMI is a risk factor for complications of a surgical nature. But we also realized that fewer of the teenagers had undergone cholecystectomy for instance, and at their baseline, more of the adults came into their operation without a gallbladder. And so the cholecystectomy rate may have had something to do with that difference. But also pediatric surgeons and pediatricians alike, I think, are more conservatively minded. And so if the patient, you know, has severe abdominal pain after an operation, we might have a lower threshold to put a scope in and take a look again. So all of these factors may play into a difference in that rate of intra abdominal operations within five years.  

Erin Spain: [00:17:16] How do the patients maintain a healthy lifestyle and healthy weight after surgery? What's the aftercare like?  

Thomas Inge, MD, PhD: [00:17:23] Yeah, that's the secret sauce. Of course, the surgery we always tell them is a tool. And so what we do in the operating room, you know, we can do over and over and over again, we can do it exactly the same way over and over and over again. And yet the humbling thing about it is that when you actually do see your ten year results and that's what we're seeing now, it's a huge spread in terms of the response, if you will, to surgery or the BMI trajectories that we are able to discern. And so there are a lot of our patients, more than half, I would say, that are maintaining more than 20% weight loss. And so some of them maintain a 30% or a 40% weight loss then, but some of them on the other side of those who have regained all their weight and then some. And so fortunately, that group is more in the ten or 15% category of the total. But nonetheless, it gives us great reason to really look at the mechanisms and try to discern what it is that surgery does, what it is that is unique about those who do regain their weight and what's unique about those who maintain a fabulous weight loss. And so what we're, of course, instructing everyone is, you know, this is the post-operative diet. This is the amount of protein you need to get. You know, you need to avoid these things, particularly in bypass patients. Bypass is not a very common operation, by the way, nowadays more common to undergo a sleeve gastrectomy, but nonetheless that healthy lifestyle, including, you know, what to eat, how to prepare food instruction is all the same, how much, you know, physical activity to get. But regardless, what we have to understand is that it's a complex operation from a biochemical standpoint, and mechanisms of weight loss and mechanisms of reversal of comorbidities are really yet to be worked out. And I have no doubt that the individual variation internally, that is to say from a metabolic standpoint and how people respond to these operations is very different in ways that they can't really change.  

Erin Spain: [00:19:33] Tell me what we can expect now that you're bringing this study to the Chicago area, what can we expect now and in years to come?  

Thomas Inge, MD, PhD: [00:19:41] We're very optimistic in that most of our participants have now marched through a ten year time point. And so we're in the process right now of putting together what I would call the long term findings. And we're very focused not only on durability of weight loss and looking now at some of the mechanisms through collaborations with some really highly sophisticated scientists that do metabolomics work and do genetics work and do proteomic work. We're looking carefully at mechanisms of change in these health conditions as well as weight. But I think that the other things that you alluded to earlier in terms of risks. We're looking carefully at, you know, late effects that are adverse as well, including effects on the bone, effects on anemia and long term effects on psychological well-being as well, mental health. I think that it's certainly also true that we're very curious what are the social determinants of the outcome of these operations. And so, you know, not just the social determinants of health, which you hear a lot about, but we in surgery, you know, that are doing, you know, operations like this that have a major impact on health.  

Erin Spain: [00:20:52] We've been talking a lot about these participants in the study, but you also know them as your patients, these families that come to you and they are looking for help. And you have seen firsthand some of those transformations. I'm sure it's very gratifying.  

Thomas Inge, MD, PhD: [00:21:06] I have, yeah. The kind of things that you see and you measure kind of in a lab setting, you know, with these instruments, you know, these standardized quality of life and so forth, that's great and that's scientific. And you can do statistics on it. But gosh, when you talk to the patients and you not only talk to them, but you see them come back to you. And when I know that I've done a good job, it's not only because of what I'm seeing on the scale, but they come in just looking like they're just having a new lease on life.  

Erin Spain: [00:21:45] Thanks for listening and be sure to subscribe to this show on Apple Podcasts or wherever you listen to podcasts and rate and reviews. Also for medical professionals, this episode of Breakthroughs is available for CME Credit. Go to our website Feinberg.Northwestern.edu and search CME.