- Teens with higher levels of PFAS before surgery had smaller improvements in HbA1c and fasting glucose
- One compound, PFHxS, was strongly linked to rising HbA1c over five years
- The findings are based on 186 adolescents in a long term bariatric surgery study
Bariatric surgery can transform the lives of teenagers with severe obesity, often leading to substantial weight loss and improved blood sugar control.
Yet not everyone benefits equally and some metabolic gains fade over time.
A new study from the Keck School of Medicine at the University of Southern California suggests that environmental pollutants may be part of the explanation.
Researchers report in Environmental Endocrinology that higher pre surgery blood levels of per and polyfluoroalkyl substances, or PFAS, were linked with smaller improvements in glucose control over the following five years.
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What are PFAS
PFAS are a large family of industrial chemicals used in non stick cookware, stain resistant fabrics and many other consumer products.
They persist in the environment and accumulate in the body.
Most adults in the United States have detectable levels in their blood.
Previous studies have linked PFAS exposure to kidney and liver problems, some cancers and possible effects on weight regulation and insulin sensitivity.
The new work focuses on how these chemicals might influence the metabolic results of bariatric surgery in adolescents.
Tracking teenagers after surgery
The study drew on data from the Teen Longitudinal Assessment of Bariatric Surgery, known as Teen LABS.
This project follows adolescents who undergo weight loss surgery and tracks their health for years afterwards.
For 186 participants aged 19 or younger, researchers measured eight different PFAS compounds in blood samples taken before surgery.
They then followed changes in fasting glucose, HbA1c, insulin and estimated insulin resistance at several time points up to five years after the operation.
Overall, most teenagers showed marked improvements in blood sugar control after surgery, reflecting better insulin sensitivity and reduced weight.
However, those with higher combined PFAS exposure had smaller falls in HbA1c and fasting glucose, and in some cases these markers began to rise again.
PFHxS stands out
One compound, perfluorohexanesulfonic acid or PFHxS, showed particularly strong associations.
Teens with higher PFHxS levels before surgery had an average yearly increase in HbA1c of about 0.15 percentage points.
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That rate of rise could shift someone from normal HbA1c to prediabetes, or from prediabetes to type 2 diabetes, within a few years. PFHxS was also linked with small but steady increases in fasting glucose.
At that pace, initial gains in fasting glucose after surgery could be erased within a decade.
The study did not find clear links between PFAS levels and insulin concentrations, though the authors note that more detailed work is needed in this area.
Why this matters for adolescents with obesity and diabetes risk
The findings add to growing evidence that environmental chemicals can influence metabolic health in subtle yet important ways.
Even after dramatic weight loss and surgical changes to the gut, underlying exposure to PFAS may limit how much improvement some teenagers see in their blood sugar.
This does not mean that bariatric surgery is ineffective for young people with severe obesity.
The procedure still brings major health benefits for most.
It does suggest that clinicians may need to consider environmental exposures when counselling patients and interpreting long term outcomes.
In the future, screening for PFAS before surgery might help identify teenagers who need closer monitoring or additional interventions to keep blood sugar on track.
At a broader level, it underlines the importance of policies that reduce PFAS in water, food and consumer products.
