The results of a new study to be published November 6, 2015 in The New England Journal of Medicine to coincide with presentation at The Obesity Society Annual meeting in Los Angeles, California show that three years after undergoing bariatric surgery, adolescents experienced major improvements in their weight, metabolic health, and quality of life.
Teen-LABS (Longitudinal Assessment of Bariatric Surgery), a multi-center clinical study examining the safety and health effects of surgical weight loss procedures, is the largest and most comprehensive analysis of bariatric outcomes to date in adolescents. The study enrolled 242 adolescents, ages 13 to 19, all of whom were severely obese with an average weight of 325 pounds before surgery. The participants had an average body mass index (BMI) of 53 kg/m2. BMI is a tool to determine if a person's weight may lead to health problems. Three years after surgery, average weight had decreased by over 90 pounds, or 27 percent. Most participants also had reversal of a number of important obesity-related health problems. Reversal of type 2 diabetes was seen in 95 percent and normalization of kidney function was seen in 86 percent. Hypertension corrected in 74 percent and lipid abnormalities reversed in 66 percent.
Previous research has shown that only 2% of severely obese teenagers can lose weight and keep it off without surgery. "This study shows that at three years, almost 90 percent experienced clinically meaningful weight loss, and participants were in better health, with improved quality of life scores," said Thomas Inge, MD, PhD, principal investigator and lead author of the study. He is also surgical director of the Surgical Weight Loss Program for Teens at Cincinnati Children's Hospital Medical Center.
"The remission rates for medical conditions such as diabetes and hypertension are greater than those we see in many studies of adults who had long-standing obesity before bariatric surgery. It is possible that earlier intervention could lead to better outcomes," said Inge. "If sustained, the improvements seen in weight, blood sugar, kidney function, blood pressure, and lipid levels may translate into fewer strokes, heart attacks and other disabilities later in life."
Nutritional and other risks associated with surgery were also well documented. The study found that fewer than five percent of study participants had iron deficiency before surgery, but more than half had low iron stores three years after surgery, supporting the recommendation for monitoring of vitamin and iron supplementation in these patients. In addition, 13 percent of patients required additional abdominal surgery, most commonly gallbladder removal, during the three-year period.
"We are also learning that once teens have crossed into these extremes of obesity, only 25 percent of them can achieve weights in the normal range after surgery, and over half of them remain severely obese even after surgery," said Dr. Michael Helmrath, a study co-author and adolescent bariatric surgeon at Cincinnati Children's. "Timing of surgery may prove important."
"Long-term studies like this one will help pediatricians and pediatric subspecialists have informed and balanced discussions with teens and their families about anticipated benefits and risks of bariatric surgery, especially important given that so many of us are now routinely caring for severely obese adolescents with significant health problems," said Dr. Stavra Xanthakos, a study co-author and pediatric gastroenterologist at Cincinnati Children's.
Limitations of the study include the fact that it is observational --not a randomized controlled trial--and that the majority of study participants are Caucasian females. However, this study population represents the patient group seeking surgery at the participating clinical centers. In addition, while participants were followed for three years post-surgery, it is possible that some of the health improvements seen may diminish and other health risks could emerge later. Thus, longer follow-up of adolescents who have bariatric surgery is critical.