Bisphenol A tied to decreased insulin sensitivity for healthy adults
Click Here to Manage Email Alerts
Key takeaways:
- Young adults receiving bisphenol A had a greater decrease in insulin sensitivity at 4 days compared with placebo.
- No differences in body weight or energy balance were seen between the two groups.
ORLANDO — Exposure to bisphenol A may lower insulin sensitivity for healthy adults and may lead to higher risk for type 2 diabetes, according to a speaker at the American Diabetes Association Scientific Sessions.
In a small, 4-day randomized controlled trial, adults receiving 50 µg/kg of body weight of once-daily oral bisphenol A (BPA) had a greater decline in insulin sensitivity than adults receiving placebo. With no changes observed in other endocrine measures, the change in insulin sensitivity could be attributed to exposure to BPA, according to Todd Hagobian, PhD, associate vice president of research in the department of kinesiology and public health at California Polytechnic State University.
“Bisphenol A administration may potentially have a direct effect on type 2 diabetes risk,” Hagobian said during a presentation.
In results from a randomized crossover study published by Hagobian and colleagues in the Journal of the Endocrine Society in 2019, adults had decreases in glucose, insulin and C-peptide 1 day after being administered BPA. However, Hagobian noted a previously published mouse study found glucose levels increased 4 days after receiving BPA after an initial decrease in glucose at day 1. This paved the way for researchers to examine the effects of BPA over a longer period than the 2019 study.
“The study purpose was to determine the effects of oral bisphenol A administration on peripheral insulin sensitivity, and we did that over several days,” Hagobian said.
Researchers enrolled 40 healthy students from California Polytechnic State University with a normal BMI to participate in the study (mean age, 21.3 years; 55% women). Participants consumed a 2-day baseline energy balance diet at the start of the study. After the baseline period, adults were randomly assigned, 1:1, to once-daily 50 µg/kg of body weight BPA or placebo for 4 days. Participants in both groups received a 4-day energy balance diet. Hagobian described how the researchers safely administered BPA to participants.
“We took the bisphenol A, and we dissolved it in 95% ethanol,” Hagobian said. “We let it sit for 24 hours, then we passed it through a sterile filter, and we dispensed it on a vanilla wafer cookie. We did that about 8 hours before the participant had to consume it. The ethanol actually evaporated, and the bisphenol A stays on the cookie.”
A hyperinsulinemic-euglycemic clamp was performed to assess insulin sensitivity at baseline and 4 days, with a higher glucose infusion rate indicating increased insulin sensitivity. Body weight, urinary BPA levels and other endocrine factors were assessed as secondary outcomes.
At baseline and 4 days, there were no difference in energy balance between the BPA and placebo groups. No change in body weight was observed for either group during the study.
“This is good because body weight and energy balance can have an independent effect on insulin sensitivity, so we can at least control for that,” Hagobian said.
Insulin, C-peptide and free fatty acid levels were similar between the two groups at baseline and 4 days. Peripheral insulin sensitivity decreased by 9% for adults receiving BPA compared with a slight insulin sensitivity increase for the placebo group. Of the participants receiving BPA, 60% had a decrease in insulin sensitivity from baseline to 4 days, 30% had a slight improvement and 10% had no change.
“Bisphenol A administration, compared to placebo, significantly decreased insulin sensitivity, it’s probably a small to medium effect,” Hagobian said.
Reference:
Hagobian TA, et al. J Endocr Soc. 2019;doi:10.1210/js.2018-00322.
Collapse
Hagobian TA. 17-OR. Presented at: American Diabetes Association Scientific Sessions; June 21-24, 2024; Orlando.
Read more about
Click Here to Manage Email Alerts