Outcomes Research in Review

Longer-Term Evidence Supporting Bariatric Surgery in Adolescents

Inge TH, Courcoulas AP, Jenkins TM, et al; Teen-LABS Consortium. Weight loss and health status 3 years after bariatric surgery in adolescents. N Engl J Med 2016;374:113–23.


 

References

Study Overview

Objective. To examine the efficacy and safety of weight-loss surgery in adolescents.

Design. Prospective observational study.

Setting and participants. Adolescents (aged 13–19 years) with severe obesity undergoing bariatric surgery at 5 U.S. hospitals and medical centers from March 2007 through February 2012. Participants were enrolled in the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study, a longitudinal prospective study that investigated the risks and benefits of adolescent bariatric surgery.

Main outcome measures . Data was collected on weight, comorbidities, cardiometabolic risk factors, nutritional status, and weight-related quality of life at research visits scheduled at 6 months, 1 year, 2 years, and 3 years post bariatric surgery. Researchers measured height and weight and blood pressure directly and calculated BMI. They assessed for comorbidities and cardiometabolic risk factors through urine and serum laboratory tests of lipids, glomerular filtration rate, albumin, glycated hemoglobin, fasting glucose level, and insulin. They assessed nutritional status with laboratory values for serum albumin, folate, vitamin B 12, 25-hydroxyvitamin D, parathyroid hormone, ferritin, transferrin, vitamin A, and vitamin B 1 erythrocyte transketolase. Researchers conducted interviews with the participants to collect information about subsequent medical or surgical procedures or, if participants missed a research visit, they obtained information through chart reviews. Finally, weight-related quality of life was assessed with the Impact of Weight on Quality of Life-Kids instrument, a validated self-report measure with 27 items divided into 4 subscales: physical comfort, body esteem, social life, and family relations.

Main results . Analysis was conducted on results for 228 of 242 participants who received Roux-en-Y gastric bypass ( n = 161) and sleeve gastrectomy ( n = 67). Results for 14 participants who received adjustable gastric banding were not included due to the small size of that group. Mean weight loss was 41 kg while mean height increased by only 0.51 cm. The mean percentage of weight loss was 27% overall and was similar in both groups, 28% in participants who underwent gastric bypass and 26% in those who underwent sleeve gastrectomy. At the 3-year visit, there were statistically significant improvements in comorbidities: 74% of the 96 participants with elevated blood pressure, 66% of the 171 participants with dyslipidemia, and 86% of the 36 participants with abnormal kidney function at baseline had values within the normal range. None of 3 participants with type 1 diabetes at baseline had resolution. However, 29 participants had type 2 diabetes (median glycolated hemoglobin 6.3% at baseline) and 19 of 20 of them for whom data were available at 3 years were in remission, with a median glycolated hemoglobin of 5.3%. There was an increase in the number of participants with micronutrient deficiencies at the 3-year mark: the percentage of participants with low ferritin levels increased from 5% at baseline to 57%, those with low vitamin B 12 increased from < 1% to 8%, and those with low vitamin A increased from 6% to 16%. During the 3-year follow-up period, 30 participants underwent 44 intrabdominal procedures related to the bariatric procedure and 29 participants underwent 48 endoscopic procedures, including stricture dilatation ( n = 11). Total scores on the Impact of Weight on Quality of Life-Kids instrument improved from a mean of 63 at baseline to 83 at 3 years.

Conclusion. Overall there were significant improvements in weight, comorbidities, cardiometabolic health, and weight-related quality of life. However, there were also risks, including increased micronutrient deficiencies and the need for subsequent invasive abdominal procedures.

Commentary

Pediatric obesity is one of the most significant health problems facing children and adolescents. According to the most recent estimates, 34.5% of all adolescents aged 12 to 19 years are overweight or obese [1]. Pediatric obesity has serious short- and long-term psychosocial and physical implications. Obese adolescents suffer from social marginalization, poor self-concept, and lower health-related quality of life [2,3]. They are at greater risk for metabolic syndrome, diabetes, obstructive sleep apnea, and conditions associated with coronary artery disease such as hyperlipidemia and hypertension [4,5]. Additionally, obesity in adolescence is strongly associated with early mortality and years of life lost [6].

Despite extensive research and public health campaigns, rates of adolescent obesity have not decreased since 2003 [1]. Diet and behavioral approaches have had limited success and are rarely sustained over time. Bariatric surgery is an approach that has been used safely and effectively in severely obese adults and is increasingly being used for adolescents as well [7]. The results of this study are encouraging in that they suggest that bariatric surgery is effective in adolescents, leading to significant and sustained weight loss over 3 years and improved cardiometabolic health and weight-related quality of life.

The procedures are not without risks as demonstrated by the findings of micronutrient deficiencies and the need for follow-up intraabdominal and endoscopic procedures. The number of follow-up procedures and the fact that they continued into the third year is concerning. More details about this finding, such as characteristics of participants who required them, would be helpful. Further research to determine risk factors associated with complications that require subsequent invasive procedures is important for developing criteria for selection of candidates for bariatric surgery. Additionally, there was no information on impact of the follow-up procedures on participants or the conditions that precipitated them. In addition, there was no information on physical sequelae that can cause ongoing distress for patients, eg, chronic abdominal cramping and pain. The authors measured weight-related quality of life but measuring overall quality of life post-procedure would have captured the impact of post-procedure dietary restrictions and any medical problems. Such data could be helpful in decision-making about the use of bariatric procedures in this population versus noninvasive approaches to management.

As the authors note, treating severe obesity in adolescence rather than waiting until adulthood may have significant implications for improved health in adulthood, particularly in preventing or reversing cardiovascular damage related to obesity-related cardiometabolic risk factors. However, what is not known yet is whether the positive outcomes, beginning with weight loss, are sustained through adulthood. This 3-year longitudinal study was the first to examine factors over an extended time period, however, considering the average life expectancy of an adolescent, it provides only a relatively short-term outlook. A longitudinal study that follows a cohort of adolescents from the time of the bariatric procedure into middle age or beyond is needed. Such a study would also provide needed information about the long-term consequences of repeated intraabdominal procedures and the persistence or resolution of micronutrient deficiencies and their effects on health.

The strengths of this study are its prospective longitudinal design and its high rate of cohort completion (99% of participants remained actively involved, completing 88% of follow-up visits). As the authors note, the lack of a control group of adolescents treated with diet and behavioral approaches prevents any definitive statement about the benefits and risks compared to nonsurgical approaches. However, previous research indicates that weight loss is not as great nor sustained when nonsurgical approaches are used.

Applications for Clinical Practice

The use of bariatric surgery in adolescents is a promising approach to a major health problem that has proven resistant to concerted medical and public health efforts and the use of nonsurgical treatments. Ongoing longitudinal research is needed but the positive outcomes seen here—sustained significant weight loss, improvement in cardiometabolic risk factors and comorbidities, and improved weight-related quality of life—indicate that bariatric surgery is an effective treatment for adolescent obesity when diet and behavioral approaches have failed. However, the occurrence of post-procedure complications also highlights the need for caution. Clinicians must carefully weigh the risk-benefit ratio for each individual, taking into consideration the long-term implications of severe obesity, any potential for significant weight loss with diet and behavioral changes, and the positive outcomes of bariatric surgery demonstrated here.

—Karen Roush, PhD, RN

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