Bariatric surgery is recognized as the most effective treatment available for adolescents with severe obesity, yet a subset (10-20%) of adolescent patients undergoing a laparoscopic sleeve gastrectomy (LSG) experience suboptimal weight loss. To understand the drivers of weight loss success in this patient population, Ilene Fennoy, MD, a pediatric endocrinologist and medical director of the Comprehensive Adolescent Bariatric Surgery Program at NewYork-Presbyterian and Columbia, and her colleagues investigated the connection between metabolic comorbidities and post-surgical weight loss outcomes in adolescents undergoing LSG. Their discovery -- pre-diabetes and elevated blood pressure are related to post-surgical weight loss success in adolescents.
Reducing the Risk of Obesity-Related Illnesses in Adolescents
Amid rising adolescent obesity rates, bariatric surgery has become an important treatment option for adolescents at risk of developing severe obesity-related disease. LSG has been shown to result in successful and lasting weight reduction when used in combination with lifestyle modification. Adolescents who undergo bariatric surgery also have significant improvement of metabolic comorbidities such as type 2 diabetes.
“Diabetes is a much more aggressive disorder in adolescents than it is in adults, and is associated with severe insulin resistance and more rapid disease progression,” says Dr. Fennoy. “Our goal as clinicians is to help adolescents find long-term treatment for obesity and reduce their risk of suffering from devastating weight-related illnesses such as type 2 diabetes.”
Dr. Fennoy and her colleagues conducted a retrospective study of subjects recruited into a comprehensive weight loss program at the Center for Adolescent Bariatric Surgery at NewYork-Presbyterian and Columbia between January 2010 and April 2021. A total of 151 study participants (34 male, 117 female) were included in the study. Anthropometric measurements and metabolic factors including blood pressure, fasting glucose, hemoglobin A1c (HbA1c), metabolic syndrome (MeS), liver function, triglycerides, and waist circumference were collected at one pre-surgical visit and at 6 and 12 months after undergoing laparoscopic sleeve gastrectomy. Weight loss was compared between subjects with normal or abnormal baseline metabolic factors. Absolute BMI change was used to measure successful weight loss.
“Adolescents with early onset diabetes or a shorter duration of diabetes at the time of bariatric surgery have better outcomes in terms of attaining long-term remission of their diabetes,” says Dr. Fennoy. “For this study, in addition to identifying the metabolic comorbidities that are associated with weight loss success, we also wanted to know what is the pre-diabetic state in the adolescent? Is it more aggressive? Does it have worse outcomes in terms of weight loss? Those are the questions of greatest concern to us.”
Adolescents with early onset diabetes or a shorter duration of diabetes at the time of bariatric surgery have better outcomes in terms of attaining long-term remission of their diabetes. In addition to identifying the metabolic comorbidities that are associated with weight loss success, we also wanted to know what is the pre-diabetic state in the adolescent? Is it more aggressive? Does it have worse outcomes in terms of weight loss? Those are the questions of greatest concern to us.
— Dr. Ilene Fennoy
Because few patients with diabetes participated in the study, the researchers did not look at diabetes as a diagnosis. “We did have patients with elevated HbA1c,” says Dr. Fennoy, “which is an indicator of impaired glucose tolerance, or pre-diabetes, so we felt that was an important group to study.”
Abnormalities of Blood Pressure and Pre-Diabetes Are Associated with Greater Weight Loss
The study found higher baseline systolic blood pressure (SBP) was associated with greater weight loss as measured by body mass index (BMI) change and BMI standard deviation score (BMI-SDS) change at 6 and 12 months. Additionally, patients in the 6-month follow-up group with an abnormal HbA1c at baseline had significantly more weight loss. None of the other parameters, including fasting glucose, MeS, liver function, triglycerides, and waist circumference, revealed a predictive relationship.
“These findings show that, although there is strong evidence for intervention in the entire patient group, you can expect particularly good, or more rapid, outcomes from patients with abnormalities of blood pressure and HbA1C,” says Dr. Fennoy. “This means we should be targeting these individuals for intervention and not waiting for them to progress to more serious disease, because they are very effective at losing weight.”
These findings show that, although there is strong evidence for intervention in the entire patient group, you can expect particularly good, or more rapid, outcomes from patients with abnormalities of blood pressure and HbA1C. We should be targeting these individuals for intervention and not waiting for them to progress to more serious disease, because they are very effective at losing weight.
— Dr. Ilene Fennoy
In light of these discoveries, Dr. Fennoy suggests abnormalities of blood pressure and HbA1C should be important considerations when evaluating an adolescent patient’s eligibility for bariatric surgery. “Under the current guidelines, if an adolescent patient is in the in-between group of BMIs, they must also have a comorbidity in order to be eligible for bariatric surgery,” she says. “Although type 2 diabetes is clearly defined as a comorbidity, pre-diabetes is not, despite awareness that impaired glucose tolerance is clearly associated with increased cardiovascular risk, as is type 2 diabetes associated with cardiovascular risk.
“We need to start looking at our pre-diabetic patients as patients who may need greater intervention and should not be excluded from eligibility,” says Dr. Fennoy. “Pre-diabetes could become an additional criteria for surgery for a patient who is at a weight that is somewhat lower but is still in the unequivocal morbid obesity category.”
We need to start looking at our pre-diabetic patients as patients who may need greater intervention and should not be excluded from eligibility. Pre-diabetes could become an additional criteria for surgery for a patient who is at a weight that is somewhat lower but is still in the unequivocal morbid obesity category.
— Dr. Ilene Fennoy
Similarly, says Dr. Fennoy, hypertension another comorbidity to consider when evaluating an adolescent patient’s eligibility for surgery. “The risk of having a metabolic abnormality at a young age is that it leads to illness in adulthood,” she says. “We are certainly seeing that with type 2 diabetes among 15-to-19-year-old patients, there is rapid progression of serious comorbidities, sometimes within 10 years. This is a very young population who, within a short amount of time, develop a medical disability. As clinicians, we need to avoid allowing adolescents to develop severe disease, especially when we have the interventions to prevent it.”
Another obesity treatment that has recently gained widespread attention are glucagon-like peptide-1 receptor (GLP-1) agonists, medications originally developed and approved for the treatment of type 2 diabetes that have since been found to cause substantial weight loss. While these medications have been approved to treat adolescent obesity, these agents are not widely available for weight loss interventions. Even less information is currently available about their long- term efficacy. “However, given what we know regarding serious comorbidities arising at youthful ages from adolescents with severe obesity, we must focus on the role played by both surgery and medications to prevent obesity from becoming a major cause of disability in young adults. If we choose not to treat a patient’s obesity and just work around it, we will not be as effective in maintaining the health of these young people as we would be if we proactively treat the obesity.”
At NewYork-Presbyterian, Dr. Fennoy finds the multidisciplinary team approach to care allows her to pursue her research interests and organize excellent programs of care. “Our adolescent bariatric surgery program requires that patients undergo nutrition counseling and make changes in behavior and exercise prior to surgery,” says Dr. Fennoy. “This requires a multidisciplinary team of experts in nutrition, pediatric gastroenterology, endocrinology, nutrition, mental health, bariatric surgery, and other specialties who collaborate to provide a type of individualized care that addresses the unique needs of this complex patient population.”
