Common Environmental Contaminant Linked to Diabetes
Perfluorinated compounds are found in a variety of consumer and industrial products such things as nonstick cookware, fire extinguishing foam, and water-repellent textiles.
Exposure to perfluorinated compounds at levels found in the general elderly population were linked to the risk for diabetes, according to the results of a cross-sectional study published in the December issue of Diabetologia.
Perfluorinated compounds are found in a variety of consumer and industrial products such things as nonstick cookware, fire extinguishing foam, and water-repellent textiles. In previous studies, the researchers and others found associations between diabetes and high levels of polychlorinated biphenyls, pesticides, and phthalates.
These findings “open up for further study on the topic of whether environmental contaminants in general, and perfluroalkyl substances (PFAS) in particular, are involved in diabetes development,” said senior author P. Monica Lind, PhD, Associate Professor in the Division of Occupational and Environmental Medicine at Uppsala University, Uppsala, Sweden. “This is still an open question,” she added.
“The primary finding in the study by Lind et al was an association between perfluorononanoic acid (PFNA) and prevalent diabetes,” commented Tamarra James-Todd, PhD, Instructor in Medicine at Brigham and Women’s Hospital, Boston, Mass. “This finding is suggestive of higher levels of PFNA altering type 2 diabetes risk. However, due to the cross-sectional nature of the study, it is unclear whether PFNA exposure occurred prior to the onset of diabetes or if people with diabetes differentially accumulate PFNA due to a variety of different exposures in the diabetes versus non-diabetes populations,” she said.
“However, this study does provide evidence for further exploring this research question prospectively to determine whether higher exposure to this particular PFA could lead to the development of type 2 diabetes,” Dr. James-Todd said.
A Non-Linear Association Between PFNA and Diabetes Found
The study involved 1,016 70-year-old men and women who underwent blood testing for seven different perfluorinated compounds. A total of 114 participants had diabetes. The seven perfluorinated compounds were detectable in virtually all individuals in the study.
While no significant relationships were observed between the seven PFAS and diabetes in linear regression analyses, an analysis of the quadratic terms showed a significant relationship between the highest PFNA levels and diabetes (OR 1.25, P=0.002). This association was not found in subjects with only minor elevations in PFNA levels.
Clinical Implications of the Findings
“As a cross-sectional study, this study cannot speak to causal links between PFNAs and type 2 diabetes,” Dr. James-Todd commented. “Furthermore, this study was conducted in an all European elderly sample. The baseline risk of type 2 diabetes is known to differ across populations and age groups, with substantially higher risk among non-whites. In addition, younger individuals may process these chemicals differently compared to older adults. Of specific interest is whether or not PFAS lead to earlier onset type 2 diabetes, as this is directly associated with diabetes-related morbidity and mortality,” she said.
“This study provides preliminary evidence for future evaluation of PFASA, an endocrine disrupting chemical, and type 2 diabetes,” Dr. James-Todd said. “Currently, it is unclear whether or not there is a causal association or what the exact mechanism might be. It is also unclear whether an individual could modify their exposure to these chemicals, as PFAS are ubiquitous in our environment. A possible reduction in PFNA exposure could lead to a reduced risk of type 2 diabetes only if future studies show a causal association between PFNA and type 2 diabetes, as well as the ability to reduce exposure to PFNA. Of note, it may be difficult for individuals to reduce their exposure to PFNA, as such policies may need to be put in place that could assist in reducing population-wide exposure to these chemicals, with implications for reducing type 2 diabetes risk, if prospective studies replicate the present study’s findings,” she said.
Previous research, including studies by both Dr. Lind and Dr. James-Todd and colleagues, has also demonstrated associations between diabetes and other environmental contaminants including polychlorinated biphenyl, organochlorine, pesticides, bisphenol A, and phthalates.