SAN ANTONIO – Earlier may be better when it comes to bariatric surgery for obesity.
Data increasingly suggest that surgery for extreme obesity during adolescence is associated with prevention or reversal of obesity-related health problems, including diabetes, frequently seen in those who remain obese into adulthood, Dr. Thomas Inge said at the annual meeting of the Obesity Society.
Currently, an estimated 4%-7% of adolescents are extremely obese, and a number of researchers have noted significant detrimental effects decades down the road and even early in adulthood for those affected by obesity and diabetes, he said.
"Bariatric surgery earlier in life may be better than waiting until many more decades have eroded the important metabolic systems in the body."
These effects include years of life lost and "typical adult life complications of diabetes," such as amputation and renal disease, said Dr. Inge, a surgeon and director of the Center for Bariatric Research and Innovation at Cincinnati Children’s Hospital Medical Center.
Particularly disturbing is the fact that as many as 50% of children in some racial subgroups – including very young children – may develop diabetes in their lifetime, he added, noting that managing diabetes and obesity in this age group is quite challenging and that outcomes are often suboptimal.
Further, school-based studies suggest that morbidly obese children and teens tend to continue to gain weight over time, adding about 1 point of body mass index and 1 inch of waist circumference each year.
In a retrospective study designed to assess the association between adolescent weight status and adult health status, Dr. Inge found that obesity at age 18 based on participant recall increased the risk of diabetes and related comorbidities in adulthood by 37%, and increased the risk of renal disease fivefold.
The study, which involved nearly 1,500 adults who were part of the Longitudinal Assessment of Bariatric Surgery (LABS) 2 study, was reported in a poster at the meeting.
"By having been severely obese as an adolescent, they really did face quite significant problems later in life," he said.
The dilemma when it comes to treating obese adolescents is that medical treatment often fails. In one study, adolescents were found to have a greater risk of failure on metformin monotherapy at every time point compared with adults. Similar, but less striking, findings have been reported with rosiglitazone.
"One might propose, then, that adolescent diabetes is a more virulent condition, and if that’s the case, shouldn’t we really be thinking about more aggressive treatment – particularly today, in light of the fact that we do have surgical therapies with very high-powered evidence of demonstrated effectiveness?" he said.
Not only have studies in adults shown that gastric bypass surgery, for example, is highly effective for reducing fat mass and improving insulin resistance and beta-cell function, but adolescent data also show a benefit.
In a small retrospective study of 11 adolescent teens with type 2 diabetes and a preoperative BMI of about 50 kg/m2, Dr. Inge found that BMI and weight decreased by 34% at 1 year follow-up.
Additionally, all participants were using medication at baseline, including one who was on insulin, and all but that one patient were off their medications at follow-up, he said, noting that the patient on insulin had successfully reduced medication dosages by 50% at follow-up. Mean glucose levels in the participants fell from 140 to 84 mmol/L, mean insulin values normalized, and insulin sensitivity measures improved dramatically. Glycosylated hemoglobin normalized, on average, and cardiovascular measures also improved.
"So this leads to the question: What could be responsible for the reduced efficacy of medical treatment in adolescents?" Dr. Inge said.
Because compliance has been good in the studies looking at this, it is possible that biological factors are involved that affect insulin resistance, and this suggests there may be an even greater role for surgery in adolescents. In both adults and adolescents, surgery has been found to dramatically improve insulin resistance.
In fact, in one study gastric bypass seemed to restore a more normal relationship between insulin sensitivity and the first-phase response – even though participants still had "impressive obesity," with a BMI of nearly 40 on average after surgery, he said.
This suggests that in adolescents something more happens as a result of bariatric surgery than just weight loss or "a change in the plumbing."
"It’s changing, perhaps, something more fundamentally important. I think it’s true that these operations are doing something fundamentally metabolic to improve the patient’s response to whatever this pathologic obesity milieu is," Dr. Inge said, noting that additional study via the Teen-LABS multisite consortium and registry is underway.