Polybrominated biphenyls, polychlorinated biphenyls, body weight, and incidence of adult-onset diabetes mellitus.
BACKGROUND
Prior studies have reported an increased risk of diabetes related to polychlorinated biphenyl (PCB) exposure. No study has yet investigated whether polybrominated biphenyls (PBBs), which are similar in chemical structure, increase the incidence of diabetes.


METHODS
The Michigan PBB cohort was established in 1976 and surveyed again in 1991-1993 and in 2001. PBB and PCB serum levels were measured from blood collected at enrollment. To determine the incidence of adult-onset diabetes, we analyzed cohort members without diabetes at enrollment, ages 20 years and older, with known PBB and PCB levels, who participated in at least 1 follow-up survey (n = 1384). Using Poisson regression, we determined the incidence density ratio (IDR) of diabetes for different serum levels of PBB and PCB, controlling for age, body mass index, smoking, and alcohol consumption at enrollment.


RESULTS
Analyzing 25 years of follow-up data, we did not find that higher PBB serum levels were a risk factor for the incidence of diabetes mellitus. However, in women, but not in men, higher PCB serum levels were associated with increased incidence of diabetes (IDR = 2.33; 95% confidence interval = 1.25-4.34 in the highest PCB group compared with the lowest). In both men and women, overweight and obesity increased the diabetes incidence.


CONCLUSIONS
We found no association between PBB serum levels and diabetes incidence. In women, there was a positive linear association of diabetes incidence with PCB serum levels at enrollment. This finding is in agreement with 2 prior studies indicating a higher relative risk of diabetes in PCB-exposed women.
Vasiliu
Oana
O
Department of Epidemiology, College of Human Medicine, Michigan State University, East Lansing, Michigan, USA.
Cameron
Lorraine
L
Gardiner
Joseph
J
Deguire
Peter
P
Karmaus
Wilfried
W
D000328:Adult; D015992:Body Mass Index; D001835:Body Weight; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000139:chemically induced / Q000453:epidemiology*; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D011075:Polybrominated Biphenyls / Q000633:toxicity*; D011078:Polychlorinated Biphenyls / Q000097:blood / Q000633:toxicity*; D012307:Risk Factors
D011075:Polybrominated Biphenyls; D011078:Polychlorinated Biphenyls