Most recent update: Wednesday, March 13, 2019 - 10:23

Bariatric News - Cookies & privacy policy

You are here

Race, weight regain and RYGB

Race plays role in weight regain after Roux-en-Y gastric bypass

While previous studies have shown that patients with obesity and T2D lose less weight with medical weight-management interventions, this is the first to identify race as a risk factor for weight regain after RYGB

African Americans and Hispanic Americans who have undergone Roux-en-Y gastric bypass (RYGB) are at greater risk to regain weight compared to Caucasians, according to researchers from Boston Medical Center (BMC), who stated that a greater degree of vigilance is warranted for African American and Hispanic American patients who are at higher risk for weight regain.

To date, no study has addressed the effect of race on weight regain over the long term and identifying the risk factors for weight regain is an important first step in improving the long-term clinical outcomes of bariatric surgery. While previous studies have shown that patients with obesity and T2D lose less weight with medical weight-management interventions, this is the first to identify race as a risk factor for weight regain after RYGB emphasizing the need for future research in diverse populations. The study, ‘Weight Recidivism After Roux-en-Y Gastric Bypass Surgery: An 11-Year Experience in a Multiethnic Medical Center’, was published in Obesity

"Racial or ethnic differences in food choices and eating behaviours have long been linked to obesity and cardiovascular disease,” explained corresponding author, Dr Nawfal W Istfan, associate professor of medicine at BUSM and attending physician in the Nutrition and Weight Management Center at BMC. “However, it is unclear whether there are racial differences in RYGB-mediated changes in appetite hormonal signals, mental health and eating behaviours."

Using a retrospective review of all RYGB cases performed at BMC from 2004 to 2015, the researchers were able to examine the effects of race and T2D on weight regain following weight loss surgery among African American (AA), Caucasian American (CA), and Hispanic American (HA) participants.

A total of 1,395 participants were included in the study with a mean age of subjects was 46.0 years. CA were significantly older than AA and HA and comorbid conditions varied significantly between racial groups. AA had a greater prevalence of T2DM than did CA, and CA had higher prevalence of dyslipidaemia than AA and HA. AA and HA were more likely to live in zip code areas with lower median income than CA.

Nadir weight was achieved between 12 and 16 months post-surgery, followed by weight regain in the following one to five years for most patients and mean weight appeared to stabilise from five to 11 years post‐RYGB. However, the mean weight trajectory of AA was consistently higher throughout the 11‐year period (including at nadir) compared with CA.

Linear mixed model analyses showed significant effects of time (<0.0001), race (p<0.0001), and race × time interaction (p=0.0008) on weight as a percent of baseline weight.

Mixed models of weight regain (Figure 1) showed a significant time‐dependent increase in weight regain (Figure 1a), WR/WL (Figure 1b) and WR/nadir (Figure 1c) following surgery. Mixed model analyses showed a significant time‐dependent decrease in monthly WR/WL (Figure 1d) following surgery with a significant effect of race (p=0.0005). AA had significantly greater WR than CA (mean difference 1.81kg, p=0.014) and HA (mean difference 1.8kg, p=0.047).

Figure 1: (A) Weight regain over time by race. (B) Weight regain/maximum weight loss over time by race. (C) Weight regain/nadir weight over time by race. (D) Monthly weight regain/maximal weight loss over time by race.

The effects of time (p<0.0001), race (p<0.0001), and race × time interaction (p=0.0008) on weight trajectory were significant. AA had significantly more weight regain than CA (p<0.01). AA and HA had a higher hazard ratio for having low, moderate, and rapid WR/nadir.

According to the researchers, the mechanisms for these racial differences in weight regain after RYGB remains unclear.

“A greater degree of vigilance is warranted for African American and Hispanic American patients who are at higher risk for weight regain. Patients with T2DM are at higher risk of weight regain compared with those without T2DM,” the authors conclude. “More frequent follow‐up visits, education, and behavioural interventions may be warranted after RYGB in African American and Hispanic American patients as well as those with T2D to avert the consequences of weight regain. Further research is needed to understand the underlying causes of racial differences in weight loss and weight regain following bariatric surgery.”

To access this paper, please click here

Want more stories like this? Subscribe to Bariatric News!

Bariatric News
Keep up to date! Get the latest news in your inbox. NOTE: Bariatric News WILL NOT pass on your details to 3rd parties. However, you may receive ‘marketing emails’ sent by us on behalf of 3rd parties.