Written by Angeline A. De Leon, Staff Writer. Study results suggest an increased risk of diabetes among Thai farmers with pesticide exposure and a statistically significant increased risk with the use of endosulfan, mevinphos, carbaryl/Sevin, and benlate.
A growing percentage of the human population continues to be diagnosed with diabetes, with over 400 million adult cases reported in 2015 and an estimated figure of about 650 million projected by 20401. Besides genetic factors and certain lifestyle behaviors, recent studies have discovered environmental contaminants, specifically involving agricultural chemicals, to play a key role in diabetes risk2. Pesticides of concern include arsenic, mercury, phthalates, and bisphenol A (BPA)3,4 and data from large cohort studies indicate a relationship between diabetes and at least seven types of organochlorine pesticides5. Researchers hypothesize that the mechanism by which toxic pesticide compounds cause metabolic disorders involves damage to the mitochondria of cells (involved in cellular energy production), resulting in impaired insulin secretion and glucose homeostasis as well as increased oxidative stress6, 7. Although cohort studies now recognize that various factors, including gender, race, and even economic status and educational level, influence the likelihood of diabetes development from pesticide exposure8, a significant gap remains in the understanding of pesticide linkage and diabetes, particularly in rural communities around the world. In an effort to identify the specific pesticide compounds most likely to contribute to diabetes in a provincial community in Thailand, a case-control study examining diabetes occurrence among Thai farmers was conducted and published in Environmental Health and Preventative Medicine (2018).
This population-based case-control study was carried out in the Bang Rakam district of Phitsanulok Province in Thailand. Participants carrying a medical diagnosis of diabetes mellitus (n = 866) were matched for gender and age and compared to control cases (close neighbors without diabetes) (n = 1021). At baseline, subjects completed structured questionnaires evaluating lifetime pesticide use and use type (mixing or applying). Pesticides were categorized into five groups: insecticides, fungicides, herbicides, rodenticides, and molluscicides.
Data analysis showed that after adjusting for age, gender, family disease history, and other confounding variables, the prevalence of diabetes was positively associated with exposure to any type of pesticide (Odds Ratio = 0.94, 95% Confidence Interval: 0.75 to 1.17), however, only exposure to rodenticides was statistically significant (OR = 1.35, 95% CI: 1.04 to 1.76). More specifically, for rodenticides, it was found that only exposure days were positively correlated with diabetes. Of the 35 pesticides tested, three insecticides (organochlorine, organophosphate, and carbamate) showed statistically significant OR’s (OR = 1.40, 95% CI: 1.01 to 1.95; OR = 2.22, 95% CI: 1.17 to 4.19; OR = 1.50, 95% CI: 1.02 to 2.19, respectively), along with one fungicide (OR = 2.08, 95% CI: 1.03 to 4.20).
Evidence from the study confirms that, in line with previous epidemiological data, pesticide exposure is associated with higher prevalence of diabetes among Thai farmers. Insecticides and fungicides appear to present particular health concerns. It is suggested that practical measures be taken by public institutions to control pesticide use and that further research be conducted on the causal effects of specific pesticide compounds.
Source: Juntarawijit C and Juntarawijit Y. Association between diabetes and pesticides: a case-control study among Thai farmers. Environmental Health and Preventative Medicine. 2018; 23(1): 3. DOI: 10.1186/s12199-018-0692-5.
© The Author(s). 2018 Open Access Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/ which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
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Posted July 31, 2018.
References:
- International Diabetes Federation. Idf Diabetes Atlas—7th edition. International Diabetes Federation. 2015.
- Kuo C-C, Moon K, Thayer KA, et al. Environmental chemicals and type 2 diabetes: an updated systematic review of the epidemiologic evidence. Curr Diab Rep. 2013; 13(6): 831–49.
- Lee D-H, Lee I-K, Song K, et al. A strong dose-response relation between serum concentrations of persistent organic pollutants and diabetes: results from the National Health and examination survey 1999-2002. Diabetes Care. 2006; 29(7): 1638–44.
- Vasiliu O, Cameron L, Gardiner J, et al. Polybrominated biphenyls, polychlorinated biphenyls, body weight, and incidence of adult-onset diabetes mellitus. Epidemiology. 2006; 17(4): 352–9.
- Montgomery MP, Kamel F, Saldana TM, et al. Incident diabetes and pesticide exposure among licensed pesticide applicators: agricultural health study, 1993-2003. Am J Epidemiol. 2008; 167(10): 1235–46.
- Hectors TLM, Vanparys C, Van Der Ven K, et al. Environmental pollutants and type 2 diabetes: a review of mechanisms that can disrupt beta cell function. Diabetologia. 2011; 54(6): 1273–90.
- Rezg R, Mornagui B, El-Fazaa S, et al. Organophosphorus pesticides as food chain contaminants and type 2 diabetes: a review. Trends Food Sci Technol. 2010; 21(7): 345–57.
- Benjamin N, Kushwah A, Sharma RK, et al. Histopathological changes in liver, kidney and muscles of pesticides exposed malnourished and diabetic rats. Indian J Exp Biol. 2006; 44(3): 228–32.
