- Exposure to higher levels of certain PFAS chemicals was associated with greater weight regain among teens who underwent bariatric surgery.
- The research suggests environmental factors like exposure to endocrine-disrupting chemicals may impact the long-term success of obesity treatment.
- PFAS are commonly used synthetic chemicals in products such as nonstick cookware, food packaging, and water-and stain-repellent textiles.
Greater exposure to per- and polyfluoroalkyl substances (PFAS), a family of endocrine-disrupting chemicals, may undermine some of the benefits of bariatric surgery for teens, data from the Teen-LABS study found.
Among 186 adolescents with obesity who underwent bariatric surgery, higher serum concentrations of three PFAS subtypes — PFOS, PFHxS, and PFHpS — were each associated with greater rate of body mass index (BMI) regain, weight regain, and increased waist circumference in the 5 years following surgery, Brittney Baumert, PhD, MPH, of the University of Southern California in Los Angeles, and co-authors reported in Obesity.
“Environmental exposures matter for weight regain following a weight-loss intervention,” Baumert told MedPage Today. “Our findings suggest that persistent PFAS chemicals may contribute to weight regain even years after bariatric surgery. “
“These findings add a new dimension to PFAS research, suggesting that these chemicals may influence not only the development of obesity but also the long-term success of obesity treatment in youth,” she added.
Widely used in society due to their water- and grease-resistant properties, PFAS are synthetic chemicals used in products such as nonstick cookware, food packaging, and water- and stain-repellent textiles.
When assessing PFAS subtypes, Baumert’s group found higher concentrations of the sulfonic acid-containing compound PFOS of 1.45 to 2.94 log2 ng/mL were tied to annual BMI regains ranging from 1.34 to 1.84 per year (β interaction=1.38, P=0.0497).
Following a similar pattern, PFHxS – another sulfonic acid-containing compound — at a concentration of -0.16 log2 ng/mL was tied to a rate of BMI regain of 1.33 per year, which increased to 1.50 per year at a higher concentration of 1.95 log2 ng/mL (β interaction=1.04, P=0.036).
As for PFHpS, the rate of BMI regain was 1.29 per year at -3.28 log2 ng/mL but increased to 2.04 per year of BMI regain at a -1.76 log2 ng/mL concentration (β interaction=2.39, P=0.017).
“Bariatric surgery is a highly effective weight-loss intervention, but there is heterogeneity in how much weight individuals regain. This exposure-related variability helps explain why some adolescents regain more weight than others despite undergoing the same intervention,” she added. “Importantly, PFAS may represent a modifiable risk factor [and] reducing exposure could become part of personalized pre- and post-weight-loss intervention care to improve long-term outcomes.”
Baumert suggested healthcare providers integrate environmental biomarker screening into clinical risk stratification tools to help tailor follow-up care and counseling to further support long-term weight loss and metabolic health in youth.
Mirroring BMI regain patterns, greater exposure to PFAS was also tied with body weight regain after bariatric surgery. For example, a PFOS concentration of 1.45 log2 ng/mL was tied with a rate of weight regain of 2.73 percentage points of baseline body weight per year but increased to 3.57 percentage points per year at a concentration of 2.94 log2 ng/mL (β interaction=2.54, P=0.040).
When stratified into three tertiles of PFHpS exposure, adolescents with the highest level of exposure had a weight regain rate of 4.31 percentage points per year versus a regain of 2.68 percentage points per year for the lowest tertile (P=0.01).
The researchers found a similar pattern when it came to waist circumference. Adolescents in the highest tertile for PFHpA concentrations had a rate of waist circumference increase of 2.74 cm per year compared with 0.29 cm per year in the lowest tertile.
For the analysis, Baumert and co-authors looked at participants in the landmark Teen-LABS (Teen-Longitudinal Assessment of Bariatric Surgery) study, which was conducted from 2007 to 2012. It included adolescents ages 19 and younger who were at Tanner Stage 4 or higher and undergoing either Roux-en-Y gastric bypass or sleeve gastrectomy.
PFAS concentrations were measured using fasting blood samples collected at each study visit.
All participants had a baseline BMI of at least 35 plus at least one obesity-related comorbidity. Average age was 17.1, most were female (76.3%) and white (72%). Baseline BMI averaged 52.5, and waist circumference 139 cm.
One year after bariatric surgery, participants lost an average of 30.5% of their baseline body weight. This dropped to 23.5% by year 5.
Some limitations included the observational study design and an inability to adjust for lifestyle and clinical covariates such as diet, physical activity, and endocrine comorbidities including polycystic ovary syndrome.
“We need studies that evaluate whether PFAS influence weight regain following other types of weight-loss intervention, such as weight-loss medications,” said Baumert. “It will also be important to replicate our findings in larger adolescent populations and to explore the biological mechanisms that link PFAS exposure to weight regulation.”
