Bariatric Surgery May Aid Very Obese Teens, 3-Year Data Show

Marlene Busko

November 09, 2015

Weight loss and cardiometabolic benefits are sustained out to 3 years following bariatric surgery in very obese teenagers with no major unforeseen adverse effects, according to the latest findings from the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study.

The results were reported by Thomas Inge, MD, PhD, director of the surgical weight-loss program for teens at Cincinnati Children's Hospital Medical Center, Ohio, at Obesity Week 2015 and simultaneously published in the New England Journal of Medicine.

In the largest, longest prospective study of gastric bypass or sleeve gastrectomy in this age group, on average obese teens lost and kept off 28% of their initial weight and had higher rates of remission for diabetes and hypertension than those seen in adults.

The 3-year adverse-effect profile "gives parents a bit more peace of mind to say that there are...customary problems [such as gallstones] that arise that may need more surgery...and that the nutritional deficiencies are mild and treatable, [but none of these adverse events] are particularly frightening," Dr Inge told Medscape Medical News.

The study also hints that extremely obese teens might benefit from earlier surgery. The body mass index (BMI) of patients drops by about a third in the first year after surgery, and then their weight inches up very slightly and plateaus, so these patients "end up staying at BMIs that are enormously elevated," Dr Inge pointed out.

Clinicians should probably act sooner and have bariatric surgery performed when a patient has a BMI of 40 kg/m2 as opposed to 53 kg/m2.

Session cochair Karen J Coleman, PhD, from Kaiser Permanente Southern California, in Pasadena, agreed. "Most people consider surgical interventions very extreme, but for kids who weigh 300 or 400 pounds — and there are many of them — [bariatric surgery] could be life-changing."

The surgery is safe, patients do well, and costs to the healthcare system are lowered, for example, when some patients no longer have diabetes or kidney disease, she added.

Looking at Long-term Effects in Teens

In the United States, an estimated 4.4 million children and adolescents are severely obese, Dr Inge explained. Bariatric surgery results in a durable 10% weight loss and has a good safety profile, and it is estimated that 1600 bariatric surgeries a year are performed in adolescents in the United States. But there are few prospective, adolescent-specific studies to guide clinical practice.

The current study looked at obese teens who had bariatric surgery and followed them for 3 years to examine weight loss, coexisting conditions, weight-related quality of life, micronutrient levels, and additional abdominal procedures.

Most teens (161; 67%) underwent Roux-en-Y gastric bypass and 67 (28%) underwent sleeve gastrectomy. The remaining 14 patients who underwent adjustable gastric banding were excluded from the main analysis because so few patients had the procedure.

At the time of surgery, patients were an average age of 17 years; 27% were 13 to 15 years old, 38% were 16 to 17 years old, and 35% were 18 to 19 years old.

Patients had an average BMI of 53 kg/m2. Only 3% had a BMI of 34 to <40 kg/m2; 44% had a BMI of 40 to 49 kg/m2; 32% had a BMI of 50 to 59 kg/m2; and 21% had a BMI of 60 to 88 kg/m2.

Patients were seen at 6 months, 1 year, 2 years, and 3 years following surgery, and retention was high: 90% and 85% of patients returned for the first and last follow-up visits, respectively.

Markedly Improved Obesity, Comorbidities

At 1 year after the procedure, patients had lost on average 30% of their initial weight and had a mean weight loss of 41 kg. At 3 years, patients who had gastric bypass had lost a mean of 28% of their initial weight, and patients who had sleeve gastrectomy had lost a mean of 26% of their initial weight.

A total of 26% of patients were no longer obese, and close to 90% had a 10% or greater reduction in BMI. Only 2% of participants who underwent gastric bypass and 4% of those who underwent sleeve gastrectomy exceeded their baseline weight at 3 years.

Moreover, in many patients baseline comorbidities were no longer present at 3 years.

At baseline, 13% of patients had type 2 diabetes, 10% had prediabetes, 17% had abnormal kidney function, 43% had elevated blood pressure, and 76% had dyslipidemia.

However, at 3 years 95% of patients with baseline diabetes, 77% of patients with prediabetes, 73% of patients with hypertension, 86% of patients with abnormal kidney function, and 66% of patients with dyslipidemia had remission of these conditions.

In comparison, after bariatric surgery only 50% to 70% of adults have remission of diabetes and 40% have remission of hypertension.

Patients' mean quality-of-life scores also improved, from 63 before surgery to 83 at 3 years.

Downsides of Surgery

A drawback of surgery was macronutrient deficiency. At 3 years, the prevalence of low serum ferritin levels increased from 5% to 57%, 16% of patients had low vitamin A levels, and 8% had low vitamin B levels.

Thus, it is important that bariatric-surgery patients receive vitamin and mineral supplements, which was achieved in this cohort, the authors write.

Moreover, about one in 10 patients (13%) required additional intra-abdominal surgery (most often gallbladder surgery and upper-GI endoscopy) 3 years after bariatric surgery.

One participant with type 1 diabetes died 3.3 years after gastric bypass surgery from complications of a hypoglycemic event.

Thus, overall, "a majority of participants in our study had marked improvements with respect to weight, obesity-related coexisting conditions, and quality of life," Dr Inge and colleagues summarized.

However, "the emergence of specific micronutrient deficiencies and the need for subsequent abdominal procedures indicate that there are also risks associated with bariatric surgery in this age group."

These are only 3-year data, and "we don't know what additional conditions could develop down the road," Dr Inge cautioned.

"But my sincere hope is that we can demonstrate at the 5- and 10-year marks that the relapse rate for teens will be lower than the adult relapse rate."

The research was supported by grants from the National Institutes of Health and National Institute of Diabetes and Digestive and Kidney Diseases. Dr Inge has received grants from National Institute of Diabetes and Digestive and Kidney Diseases during the conduct of the study, grant support from Ethicon EndoSurgery, and personal fees from Sanofi. Disclosures for the coauthors are listed on the journal website .

N Engl J Med. Published online November 6, 2015. Full text

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