Bariatric surgery tied to substantial weight loss in obese teens

Metabolic and bariatric surgery (MBS) significantly reduced BMI in severely obese adolescents compared with intensive nonsurgical treatment in the AMOS2* study.

This open-label, multicentre trial analysed 50 adolescents (mean age 15.8 years) with severe obesity (mean BMI 42.6 kg/m²) who were recruited from three tertiary university hospitals in Sweden. The participants were randomly assigned to either MBS (Roux-en-Y gastric bypass [n=23] and sleeve gastrectomy [n=2]) or intensive nonsurgical treatment (n=25). All patients were started on a low-calorie diet for 2 and 8 weeks in the surgical and nonsurgical groups, respectively. The nonsurgical treatment consisted of a balanced diet (approximately 1,500 calories/day) and a physical activity plan (60-minute moderate-to-vigorous intensity activity daily). [Lancet Child Adolesc Health 2023;7:249-260]

After 2 years of follow-up, patients who underwent MBS experienced a significant decrease in BMI compared with those who received intensive nonsurgical treatment (12.6 vs 0.2 kg/m²; p<0.0001). This translated to a greater percentage of patients attaining a BMI of <30 kg/m² in the MBS group than the nonsurgical group (63.0 percent vs 4.0 percent).

The MBS group also achieved a 28.7-percent reduction in body weight, whereas those in the intensive nonsurgical group experienced an increase of 0.4 percent (p<0.0001).

Significantly more patients in the MBS group achieved a ≥10-percent reduction in total body weight than the nonsurgical group (92.0 percent vs 26.0 percent; p<0.0001).

With regard to obesity-related cardiometabolic risk factors, the MBS group had greater improvements in oral glucose tolerance test (-3.00 vs -1.30 mmol/L), triglycerides (-0.40 vs 0.00 mmol/L; p=0.0017), and high-sensitivity C-reactive protein (-3.20 vs -0.10 mg/L; p=0.010) vs the nonsurgical group at 2 years.

However, there were no significant differences in blood pressure and alanine aminotransferase levels between the two groups.

In terms of quality of life (QoL), a significantly improved physical functioning, as determined by RAND-36 scores, was observed with MBS compared with intensive nonsurgical treatment (mean change from baseline, 25.00 vs 0.70; p=0.0003). Mental and obesity-related QoL did not differ significantly between the two groups.

With regard to eating behaviours, binge-eating and uncontrolled eating scores were significantly reduced in the MBS group vs the nonsurgical group (mean change from baseline, -9.20 vs -2.10; p=0.0042 and -25.50 vs -12.70; p=0.042, respectively).

The MBS group also demonstrated a significant decrease in DXA** bone mineral density z-score total body (mean change from baseline, -0.90 vs 0.00; p<0.0001) and DXA bone mineral content (mean change from baseline, -147.60 vs 99.3 g/cm²; p=0.0002) than the nonsurgical group.

There were no significant differences between groups in gastrointestinal symptoms, such as diarrhoea, indigestion, constipation, and abdominal pain. “The similarity between surgical and nonsurgical treatment in gastrointestinal function is, to the best of our knowledge, a new finding, further suggesting that MBS is well tolerated,” the researchers noted.

“Overall, MBS was superior to intensive nonsurgical treatment over 2 years in achieving weight loss, along with improvements in several secondary efficacy outcomes, among adolescents with severe obesity,” said the researchers.

“The reduction in BMI following MBS in this study was similar to previous observational studies in adolescents, and data also confirm a substantial variability in the surgical treatment response,” they added.

*AMOS2: Adolescent Morbid Obesity Surgery 2

**DXA: Dual-energy X-ray absorptiometry