Weight loss after bariatric surgery is typically durable

Last Updated: 2017-12-12

By Marilynn Larkin

NEW YORK (Reuters Health) - Patients experience weight fluctuations after bariatric surgery, but for most, weight loss tends to be durable for up to seven years, researchers say.

"This report helps to more completely fill important knowledge gaps about longer-term outcomes from bariatric surgical procedures using data from a large multisite study with prospective and standardized assessment and follow-up," Dr. Anita Courcoulas of the University of Pittsburgh Medical Center told Reuters Health.

Dr. Courcoulas and colleagues examined data from the Longitudinal Assessment of Bariatric Surgery study, an observational study conducted in six geographically diverse U.S. centers. Findings were reported online December 6 in JAMA Surgery.

Among 2,348 participants, 74% underwent Roux-en-Y gastric bypass (RYGB) and 26% underwent laparoscopic adjustable gastric banding (LAGB) between 2006 and 2009. At baseline, the 1,738 RYBG patients (80% women, 85% white) had a median age of 45 and a median body-mass index of 47; the 610 LAGB patients (76% women, 90% white) had a median age of 48 and a median BMI of 44.

Seven years after RYGB, mean weight loss was 38.2 kg (28.4% of baseline weight); between three and seven years of follow-up, mean weight regain was 3.9%. Seven years after LAGB, mean weight loss was 18.8 kg (14.9% lost since baseline), with a 1.4% regain.

The researchers identified six different weight-change trajectories for RYGB and seven for LAGB. Patterns of loss and regain varied, but for most participants, weight regain from three to seven years was small relative to weight loss at three years.

Dr. Courcoulas noted that the "individual variability in patterns of surgical weight loss over time points to the need to further define and understand more-specific predictors of the individual response to bariatric surgery that could help to tailor more-personalized treatment."

With regard to comorbid conditions, dyslipidemia prevalence was lower seven years after both procedures, whereas the prevalence of diabetes and hypertension was lower only after RYGB.

Among individuals with baseline diabetes - 28% of those undergoing RYGB and 29% for LAGB - the proportion in remission went from 71.2% at year one to 60.2% at year seven for RYGB, and from 30.7% to 20.3% for LAGB.

There were 59 deaths following RYGB and 15 after LAGB, corresponding to rates of 3.7 and 2.7 deaths per 700 person-years, respectively.

Fourteen RYGB and 160 LABG participants underwent reoperations, corresponding to rates of 0.92 and 30.3 reoperations per 700 person-years, respectively.

Dr. Kelvin Higa of the University of California San Francisco, Fresno, coauthor of a related editorial, told Reuters Health, "Although this study was not randomized or designed to compare outcomes of one procedure over another, it is clear that the gastric bypass is a more effective operation than the adjustable gastric band."

"However," he added, "the study also demonstrates distinct weight-loss patterns in each group and illustrates the variable response of the therapy applied to individual patients."

"The most common operation performed today, the gastric sleeve, was not performed with enough frequency at the time of the study, so it is not represented, but most likely will be somewhere between the bypass and band in terms of weight loss and weight maintenance," he said by email.

"Readers must not interpret this data to mean that one operation is better than another," Dr. Higa stressed. "The choice of procedure depends on many other factors and recommendations - and should be tailored to the needs of the individual patient."

Like Dr. Higa, Dr. Michael Russo of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, California noted that only two types of procedures were included.

"Since the study did not include the now most popular sleeve gastrectomy, it likely underestimates the true long-term success of weight-loss operations."

"Hopefully, we will continue to see high-quality studies like this one that (show) the long-term benefits of bariatric surgery and its ability to change the quality of peoples' lives," he concluded.

SOURCES: http://bit.ly/2nUhrai and http://bit.ly/2iWNi4W

JAMA Surg 2017.