Pesticide-Induced Diseases: Diabetes
According to the American Diabetes Association, diabetes is a group of diseases characterized by high blood glucose levels that result from defects in the body’s ability to produce and/or use insulin. Type 1 diabetes is usually diagnosed in children and young adults. In type 1 diabetes, the body does not produce insulin. Type 2 diabetes is the most common form of diabetes and is most common in communities of color and the aged population. In type 2 diabetes, either the body does not produce enough insulin or the cells ignore the insulin. Pesticides and other environmental factors are almost always linked to type 2 diabetes.
- Does early-life exposure to organophosphate insecticides lead to prediabetes and obesity
Researchers gave neonatal rats chlorpyrifos, diazinon or parathion in doses devoid of any acute signs of toxicity, straddling the threshold for barely-detectable cholinesterase inhibition. Organophosphate exposure during a critical developmental window altered the trajectory of hepatic adenylyl cyclase/cyclic AMP signaling, culminating in hyperresponsiveness to gluconeogenic stimuli. Consequently, the animals developed metabolic dysfunction resembling prediabetes. When the organophosphate-exposed animals consumed a high fat diet in adulthood, metabolic defects were exacerbated and animals gained excess weight compared to unexposed rats on the same diet. At the same time, the high fat diet ameliorated many of the central synaptic defects caused by organophosphate exposure, pointing to nonpharmacologic therapeutic interventions to offset neurodevelopmental abnormalities, as well as toward fostering dietary choices favoring high fat intake. These studies show how common insecticides may contribute to the increased worldwide incidence of obesity and diabetes.
[Slotkin, T.A. 2011. Reproductive Toxicology. 31: 297–301.]
- Low Dose of Some Persistent Organic Pollutants Predicts Type 2 Diabetes: A Nested Case–Control Study
Study links low dose exposure to some persistent organic pollutants (POPs) to type 2 diabetes. The authors report that some POPs, including highly chlorinated PCBs, PBB153 and the organochlorine insecticides trans-nonachlor, oxychlordane and mirex, were associated with type 2 diabetes over an 18-year period, especially in obsese people. However, POPs did not show a traditional dose–response relationship with diabetes. Instead, POPs showed strong associations at relatively low exposures. The authors conclude that exposure to relatively low concentrations of certain POPs may play a role in the increased incidence of diabetes in the United States.
[Lee D-H, et al. 2010. Environ Health Perspect 118(9): doi:10.1289/ehp.0901480]
- An Environment-Wide Association Study (EWAS) on Type 2 Diabetes Mellitus
An analysis of 266 potential environmental contributors to type 2 diabetes links the disease to individuals who have higher levels of polychlorinated biphenyls (PCBs) and the pesticide heptachlor, as well a form of vitamin E found at high levels in soybean and corn oil. The researchers used NHANES data from 1999 to 2006. Type 2 diabetes prevalence among those with high levels of heptachlor epoxide, a break down product of heptachlor, was at about two times higher than those with low levels of the compound.
[Patel CJ, et al. 2010. PLoS ONE 5(5): e10746.]
- Arsenic Exposure and Prevalence of Type 2 Diabetes in US Adults
Using National Health and Nutrition Examination Survey (NHANES) data, this study investigates the association of arsenic exposure, as measured in urine, with the prevalence of type 2 diabetes in a representative sample of US adults. Common sources of inorganic arsenic exposure include dietary exposure, drinking water pollution, and contamination associated with arsenic wood preservatives such as sawdust, smoke, direct contact, and hazardous waste sites. After adjustment for diabetes risk factors and markers of seafood intake, participants with type 2 diabetes had a 26% higher level of total arsenic (95% confidence interval [CI], 2.0%-56.0%) than participants without type 2 diabetes.
[Navas-Acien, Ana, et al. 2008. JAMA. 300(7):814-822]
- Incident Diabetes and Pesticide Exposure among Licensed Pesticide Applicators: Agricultural Health Study, 1993–2003
A study by the National Institutes of Health (NIH), including the National Institute of Environmental Health Sciences (NIEHS) and the National Cancer Institute (NCI), finds pesticide applicators with regular exposure to pesticides to be at a greater risk of type-2 diabetes. Seven different pesticides produced an increase in risk. Applicators who had used the insecticides aldrin, chlordane, and heptachlor more than 100 lifetime days had 51%, 63%, and 94% increased odds of diabetes, respectively. Researchers looked at data from 31,787 pesticide applicators in North Carolina and Iowa over a period of five years, enrolled in the Agricultural Health Study. [Montgomery et al. American Journal of Epidemiology 2008 167(10):1235-1246]
- Environmental pollution and diabetes: a neglected association
Using cross-sectional data from the 1999–2002 National Health and Nutrition Examination Survey (NHANES), University of Cambridge scientists reported a strong correlation between insulin resistance (which can lead to adult onset diabetes) and serum concentrations of persistent organic pollutants (POPs), especially for organochlorine pesticide compounds. The scientists are advocating additional research into the little understood links between environmental pollution and adult onset diabetes.
[Oliver, AH et al. 2008. The Lancet, Vol. 371, Issue 9609, Pages 287-288]
- Pesticide Exposure and Self-Reported Gestational Diabetes Mellitus in the Agricultural Health Study
Study finds exposure of pregnant women to agricultural pesticides during the first trimester may double the risk of gestational diabetes. The study group was comprised of 11,273 women married to licensed pesticide applicators. Agricultural pesticide exposure during pregnancy, such as mixing or applying pesticides or repairing pesticide application equipment, resulted in an odds ratio of 2.2 (95% CI 1.5-3.3).
[Saldana, T., et al. Diabetes Care. March 2007 30:529-534]
- A strong dose-response relation between serum concentrations of persistent organic pollutants and diabetes: results from the National Health and Examination Survey 1999-2002
Cross-sectional associations of the serum concentrations of persistent organic pollutants (POPs) with diabetes prevalence were investigated in 2,016 adult participants in the National Health and Nutrition Examination Survey 1999-2002. Six POPs (2,2',4,4',5,5'-hexachlorobiphenyl, 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin, 1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin, oxychlordane, p,p'-dichlorodiphenyltrichloroethane, and trans-nonachlor) were selected, because they were detectable in >or=80% of participants. Compared with subjects with serum concentrations below the limit of detection, after adjustment for age, sex, race and ethnicity, poverty income ratio, BMI, and waist circumference, diabetes prevalence was strongly positively associated with lipid-adjusted serum concentrations of all six POPs. The association was consistent in stratified analyses and stronger in younger participants, Mexican Americans, and obese individuals. There were striking dose-response relations between serum concentrations of six selected POPs and the prevalence of diabetes. The strong graded association could offer a compelling challenge to future epidemiologic and toxicological research.
[Lee DH, Lee IK, Song K, Steffes M, Toscano W, et al. 2006. Diabetes Care. 29(7):1638-44.]
- Increased Rate of Hospitalization for Diabetes and Residential Proximity of Hazardous Waste Sites
Study finds increased rate of hospitalization for diabetes in those who live close to hazardous waste sites containing persistent organic pollutants (POPs), including pesticides. The rate ratios for diabetes discharges for people residing in POP sites, after adjustment for potential confounders were 1.23 [95% confidence interval (CI), 1.15–1.32]. In a subset of POP sites along the Hudson River, where there is higher income, less smoking, better diet, and more exercise, the rate ratio was 1.36 (95% CI, 1.26–1.47) compared to clean sites.
[Kouznetsova M, et al. 2006 Environ Health Perspect 115(1)]