High PCB exposure tied to diabetes risk

NEW YORK (Reuters Health) - People who have been exposed to high levels of toxic polychlorinated biphenyls (PCBs) may face an elevated risk of type 2 diabetes, a new study shows.

The findings, reported in the journal Diabetes Care, come from a long-term study of Taiwanese adults who, in the 1970s, had been poisoned by cooking oil contaminated with PCB pollutants.

Once used in products ranging from fluorescent lights and appliances to insulation and insecticide, PCBs were banned in the late 1970s as carcinogens and general health hazards. They linger in the environment, however.

In the new study, Dr. Yueliang Leon Guo, from the National Taiwan University in Taipei, and colleagues examined the incidence of type 2 diabetes among 378 Taiwanese "oil disease" victims and 370 of their neighbors who had not been poisoned.

They found that women who had been exposed to the PCB-laced oil were twice as likely as other women to develop type 2 diabetes over 24 years. And women who had been most severely affected by the PCB exposure had a more than five-times higher diabetes risk.

There were no similar risks seen in men, however.

Other studies have found that people with diabetes tend to have relatively higher levels of organic pollutants, such as PCBs, in their blood. In comments to Reuters Health, Guo said that since "everyone" has detectable PCB levels in his or her body, it's possible that exposure to such pollutants has helped feed the widespread rise in diabetes in recent decades.

"The public health implication of these findings can be huge," Guo added, "considering the burden of diabetes and its multiple long-term complications."

SOURCE: Diabetes Care 2008, August 2008.