Strong associations between low-dose organochlorine pesticides and type 2 diabetes in Korea

Investigating the levels of organochlorine pesticides in human milk at three lactational stages: an intensive Ghanaian study

During breastfeeding, the human breasts secrete three different kinds of milk. Research indicates that newborns exposed to organochlorine pesticides (OCPs) during developmental stages, even at low concentrations, may suffer irreparable harm. The study aimed to ascertain whether OCPs levels in human milk vary across lactational stages. University of Health and Allied Sciences Research Ethics Committee (UHAS- REC) examined and approved the study protocol. 47 volunteers were chosen using purposive sampling. Each participant donated 15 ml of each type of breast milk. Colostrum was taken shortly after delivery up to day 4, transitional milk between day 5 and two weeks postpartum, while mature milk was taken two weeks afterwards. A modified version of QuEChERS was used to process 10.0 g aliquot of each breast milk sample, and the resulting extracts analysed for OCPs employing a Gas Chromatograph, Varian CP 3800, fitted with electron capture detector (ECD). The detection threshold was not reached for any of the six OCPs tested. This implied that none of the breast milk components analysed in this study contained any detectable levels of OCPs that might have posed any serious health risks to the infants through breastfeeding. Aldrin, chlordane, DDT, dieldrin, endrin, and heptachlor were not found in detectable quantities in mothers' milk during the three stages of lactation. Our findings are encouraging. The study's findings likely show that the Stockholm Convention's campaign to remove POPs from the environment seems to be yielding positive impact.

Research progress on remediation of organochlorine pesticide contamination in soil

Deteriorated soil pollution has grown into a worldwide environmental concern over the years. Organochlorine pesticide (OCP) residues, featured with ubiquity, persistence and refractoriness, are one of the main pollution sources, causing soil degradation, fertility decline and nutritional imbalance, and severely impacting soil ecology. Furthermore, residual OCPs in soil may enter the human body along with food chain accumulation and pose a serious health threat. To date, many remediation technologies including physicochemical and biological ways for organochlorine pollution have been developed at home and abroad, but none of them is a panacea suitable for all occasions. Rational selection and scientific decision-making are grounded in in-depth knowledge of various restoration techniques. However, soil pollution treatment often encounters the interference of multiple factors (climate, soil properties, cost, restoration efficiency, etc.) in complex environments, and there is still a lack of systematic summary and comparative analysis of different soil OCP removal methods. Thus, to better guide the remediation of contaminated soil, this review summarized the most commonly used strategies for OCP removal, evaluated their merits and limitations and discussed the application scenarios of different methods. It will facilitate the development of efficient, inexpensive and environmentally friendly soil remediation strategies for sustainable agricultural and ecological development.

The Association between Long-Term DDT or DDE Exposures and an Altered Sperm Epigenome-a Cross-Sectional Study of Greenlandic Inuit and South African VhaVenda Men

BACKGROUND

The organochlorine dichlorodiphenyltrichloroethane (DDT) is banned worldwide owing to its negative health effects. It is exceptionally used as an insecticide for malaria control. Exposure occurs in regions where DDT is applied, as well as in the Arctic, where its endocrine disrupting metabolite, p , p ' -dichlorodiphenyldichloroethylene (p , p ' -DDE) accumulates in marine mammals and fish. DDT and p , p ' -DDE exposures are linked to birth defects, infertility, cancer, and neurodevelopmental delays. Of particular concern is the potential of DDT use to impact the health of generations to come via the heritable sperm epigenome.

OBJECTIVES

The objective of this study was to assess the sperm epigenome in relation to p , p ' -DDE serum levels between geographically diverse populations.

METHODS

In the Limpopo Province of South Africa, we recruited 247 VhaVenda South African men and selected 50 paired blood serum and semen samples, and 47 Greenlandic Inuit blood and semen paired samples were selected from a total of 193 samples from the biobank of the INUENDO cohort, an EU Fifth Framework Programme Research and Development project. Sample selection was based on obtaining a range of p , p ' -DDE serum levels (mean = 870.734 ± 134.030  ng / mL ). We assessed the sperm epigenome in relation to serum p , p ' -DDE levels using MethylC-Capture-sequencing (MCC-seq) and chromatin immunoprecipitation followed by sequencing (ChIP-seq). We identified genomic regions with altered DNA methylation (DNAme) and differential enrichment of histone H3 lysine 4 trimethylation (H3K4me3) in sperm.

RESULTS

Differences in DNAme and H3K4me3 enrichment were identified at transposable elements and regulatory regions involved in fertility, disease, development, and neurofunction. A subset of regions with sperm DNAme and H3K4me3 that differed between exposure groups was predicted to persist in the preimplantation embryo and to be associated with embryonic gene expression.

DISCUSSION

These findings suggest that DDT and p , p ' -DDE exposure impacts the sperm epigenome in a dose-response-like manner and may negatively impact the health of future generations through epigenetic mechanisms. Confounding factors, such as other environmental exposures, genetic diversity, and selection bias, cannot be ruled out. https://doi.org/10.1289/EHP12013.

Pesticides in vegetable production in Bangladesh: A systemic review of contamination levels and associated health risks in the last decade

This paper reviewed the published data on the levels of different pesticide residues in vegetables (tomato, eggplant, beans, gourds, cauliflower, cabbage, cucumber, potato, carrot, onion, red chilli, red amaranth, lady's finger, spinach, coriander, and lettuce) from Bangladesh in the last decade. Vegetable production in Bangladesh has increased tremendously (37.63%) compared to the last decades, along with its pesticide use. The most observed pesticide groups used in vegetable production were organophosphorus, pyrethroids, carbamate, organochlorine, nereistoxin analogue group, and neonicotinoids. More specifically, chlorpyrifos, dimethoate, diazinon, and malathion were the most used pesticides. More than 29% of the vegetable samples (1577) were contaminated with pesticide residue; among the contaminated samples (458), most cases (73%) exceeded the maximum residue limits (MRLs). The pesticide-contaminated vegetables were cucumber (51%), tomato (41%), cauliflower (31%), miscellaneous vegetables (36%), eggplant (29%), beans (23%), cabbage (18%), and gourds (16%). Among the pesticide-contaminated samples, vegetables with above MRL were gourds (100%), beans (92), tomato (78%), eggplant (73%), miscellaneous vegetables (69%), cucumber (62%), cabbage (50%), cauliflower (50%) (p < 0.05). It was also observed that a single vegetable was often contaminated with multiple pesticides, and farmers did not follow a proper withdrawal period while using pesticides. Hazard quotation (HQ>1) was observed in adolescents and adults in tomato, eggplant, beans, cauliflower, cabbage, cucumber, lady's finger, lettuce, and coriander. There was no health risk observed (HQ<1) in gourds, potato, carrot, onion, red chilli, red amaranth, spinach, and okra. The highest acute and chronic HQ (aHQ, cHQ) was observed for cypermethrin (bean) in adolescents (aHQ=255, cHQ= 510) and adults (aHQ=131, cHQ=263). It was also observed that these pesticides harmed air, soil, water, and non-target organisms. Nevertheless, the review will help the government develop policies that reduce pesticide use and raise people's awareness of its harmful effects.

Pesticides and insulin resistance-related metabolic diseases: Evidences and mechanisms

The use of pesticides in the past century has lot helped humankind in improving crops' field and general hygiene level. Nevertheless, there has been countless evidences on the toxic effects of pesticides on the living systems. The link of exposure to pesticides with different human chronic diseases in the context of carcinogenicity, neurotoxicity, developmental toxicity, etc., have been evaluated in various types of studies. There are also some evidences on the link of exposure to pesticides with higher incidence of metabolic diseases associated with insulin resistance like diabetes, obesity, metabolic syndrome, hypertension, polycystic ovary syndrome and chronic kidney diseases. Physiologically, weakening intracellular insulin signaling is considered as a compensatory mechanism for cells to cope with cellular stresses like xenobiotic effects, oxidative stress and inflammatory responses, but it can pathologically lead to a defective cycle with lowered sensitivity of the cells to insulin which happens in metabolic disorders. In this work, the data related to metabolic toxicity of pesticides categorized in the mentioned metabolic diseases with a focus on the effects of pesticides on insulin signaling pathway and the mechanisms of development of insulin resistance will be systematically reviewed and presented.

Polychlorinated biphenyls and organochlorine pesticides in surface sediments from river networks, South Korea: Spatial distribution, source identification, and ecological risks

In this study, the nationwide monitoring of 65 polychlorinated biphenyls (PCBs) and 23 organochlorine pesticides (OCPs) in surface sediments was conducted at 77 sites in river networks in South Korea. The concentrations of ∑PCBs were relatively high in industrial sites (0.0297-138 ng/g dry weight (dw); mean 15.1 ng/g dw; median 5.44 ng/g dw), followed by industrial and agricultural (not detected (ND)-15.2 ng/g dw; mean 1.23 ng/g dw; median 0.513 ng/g dw), other sites (0.0369-0.209 ng/g dw; mean 0.116 ng/g dw; median 0.101 ng/g dw), and agricultural (0.0119-0.359 ng/g dw; mean 0.117 ng/g dw; median 0.0476 ng/g dw). The distribution and composition of PCBs in sediments are affected by past use of commercial products, atmospheric deposition, wastewater effluents, and manufacturing processes. The concentrations of ∑OCPs in industrial sites ranged from 0.0587 to 8.70 ng/g dw (mean 1.85 ng/g dw; median 0.989 ng/g dw), followed by industrial and agricultural (ND-8.54 ng/g dw; mean 0.739 ng/g dw; median 0.343 ng/g dw), other sites (0.0247-0.143 ng/g dw; mean 0.0939 ng/g dw; median 0.114 ng/g dw), and agricultural (0.00838-0.931 ng/g dw; mean 0.232 ng/g dw; median 0.0752 ng/g dw). Hexachlorobenzene and pentachlorobenzene are unintentionally generated in industries and combustion processes. Dichlorodiphenyltrichloroethanes and chlordane were dominantly distributed by historical use, whereas recent inputs (i.e., long-range transport and atmospheric deposition) were related to aldrin, heptachlor, and hexachlorocyclohexanes. The ecological risks determined by the sediment quality guidelines and mean probable effect level quotients were acceptable, except at two sites.

The diabetogenic effects of pesticides: Evidence based on epidemiological and toxicological studies

While the use of pesticides has improved grain productivity and controlled vector-borne diseases, the widespread use of pesticides has resulted in ubiquitous environmental residues that pose health risks to humans. A number of studies have linked pesticide exposure to diabetes and glucose dyshomeostasis. This article reviews the occurrence of pesticides in the environment and human exposure, the associations between pesticide exposures and diabetes based on epidemiological investigations, as well as the diabetogenic effects of pesticides based on the data from in vivo and in vitro studies. The potential mechanisms by which pesticides disrupt glucose homeostasis include induction of lipotoxicity, oxidative stress, inflammation, acetylcholine accumulation, and gut microbiota dysbiosis. The gaps between laboratory toxicology research and epidemiological studies lead to an urgent research need on the diabetogenic effects of herbicides and current-use insecticides, low-dose pesticide exposure research, the diabetogenic effects of pesticides in children, and assessment of toxicity and risks of combined exposure to multiple pesticides with other chemicals.

Association between exposure to organophosphorus pesticides and the risk of diabetes among US Adults: Cross-sectional findings from the National Health and Nutrition Examination Survey

OBJECTIVE

Organophosphorus pesticides (OPPs) are commonly used pesticides across the world, however there is little epidemiological evidence linking their exposure to diabetes. Hence, this study aimed at investigating the effect of OPP exposure on the prevalence of diabetes in American adults.

METHODS

Adults (≥20 years old) were eligible for this study from the National Health and Nutrition Examination Survey (NHANES). Multivariate logistic regression model was employed to explore the associations of six main urinary OPPs metabolites with diabetes. Subgroup analyses were performed by age and gender. Combined effect of OPPs metabolites on the overall association with diabetes was evaluated by weighted quantile sum regression (WQS). Furthermore, Bayesian kernel machine regression (BKMR) model was implemented to explore joint effect of multiple OPPs metabolites on diabetes.

RESULTS

Ultimately, 6,593 adults were included in our analysis. Of them, 1,044 participants were determined as diabetes patients. The results of logistic regression shown that urinary OPPs metabolites concentrations, whether taken as continuous variables or quantiles, were in positive correlation with diabetes. Notably, the p for trend of diethylphosphate (DEP), a kind of OPPs metabolites, was less than 0.05 indicated that a linear trend may exist between levels of DEP and prevalence of diabetes among adults while this trend was not obversed in other OPPs metabolites. In the WQS model, combined exposure of OPPs metabolites had a significantly positive association with diabetes (OR: 1.057; 95% CI: 1.002, 1.114) and diethylphosphate (36.84%) made the largest contributor to the WQS index. The result of BKMR also suggested a positive trend of association between mixed OPPs metabolites and diabetes.

CONCLUSION

Our results add credibility to the argument that OPP exposure might trigger diabetes. Certainly, prospective data are required to corroborate our findings.

Persistent organic pollutants and β-cell toxicity: a comprehensive review

Persistent organic pollutants (POPs) are a diverse family of contaminants that show widespread global dispersion and bioaccumulation. Humans are continuously exposed to POPs through diet, air particles, and household and commercial products; POPs are consistently detected in human tissues, including the pancreas. Epidemiological studies show a modest but consistent correlation between exposure to POPs and increased diabetes risk. The goal of this review is to provide an overview of epidemiological evidence and an in-depth evaluation of the in vivo and in vitro evidence that POPs cause β-cell toxicity. We review evidence for six classes of POPs: dioxins, polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), organophosphate pesticides (OPPs), flame retardants, and per- and polyfluoroalkyl substances (PFAS). The available data provide convincing evidence implicating POPs as a contributing factor driving impaired glucose homeostasis, β-cell dysfunction, and altered metabolic and oxidative stress pathways in islets. These findings support epidemiological data showing that POPs increase diabetes risk and emphasize the need to consider the endocrine pancreas in toxicity assessments. Our review also highlights significant gaps in the literature assessing islet-specific endpoints after both in vivo and in vitro POP exposure. In addition, most rodent studies do not consider the impact of biological sex or secondary metabolic stressors in mediating the effects of POPs on glucose homeostasis and β-cell function. We discuss key gaps and limitations that should be assessed in future studies.

Differential Bioaccumulation Patterns of α, β-Hexachlorobenzene and Dicofol in Adipose Tissue from the GraMo Cohort (Southern Spain)

To identify bioaccumulation patterns of α-, β- hexachlorocyclohexane (HCH) and dicofol in relation to sociodemographic, dietary, and lifestyle factors, adipose tissue samples of 387 subjects from GraMo cohort in Southern Spain were analyzed. Potential predictors of these organochlorine pesticides (OCP) levels were collected by face-to-face interviews and assessed by multivariable linear and logistic regression. OCPs were detected in 84.2% (β-HCH), 21.7% (α-HCH), and 19.6% (dicofol) of the population. β-HCH levels were positively related to age, body mass index (BMI), mother's occupation in agriculture during pregnancy, living in Poniente and Alpujarras, white fish, milk and water consumption, and negatively related to being male, living near to an agricultural area, working ≥10 years in agriculture, and beer consumption. Detectable α-HCH levels were positively related to age, BMI, milk consumption, mother's occupation in agriculture during pregnancy, and negatively with residence in Poniente and Alpujarras, Granada city, and Granada Metropolitan Area. Residence near to an agricultural area, smoking habit, white fish and water consumption, and living in Poniente and Alpujarras, Granada city and Granada Metropolitan Area were negatively associated with detectable dicofol levels. Our study revealed different bioaccumulation patterns of α, β-HCH and dicofol, probably due to their dissimilar period of use, and emphasize the need for assessing the exposure to frequently overlooked pollutants.

Sex-specific Associations Between Type 2 Diabetes Incidence and Exposure to Dioxin and Dioxin-like Pollutants: A Meta-analysis

The potential for persistent organic pollutants (POPs), including dioxins and dioxin-like polychlorinated biphenyls (DL-PCBs), to increase the risk of incident diabetes in adults has been extensively studied. However, there is substantial variability in the reported associations both between and within studies. Emerging data from rodent studies suggest that dioxin disrupts glucose homeostasis in a sex-specific manner. Thus, we performed a review and meta-analysis of relevant epidemiological studies to investigate sex differences in associations between dioxin or DL-PCB exposure and type 2 diabetes incidence. Articles that met our selection criteria (n = 81) were organized into the following subcategories: data stratified by sex (n = 13), unstratified data (n = 45), and data from only 1 sex (n = 13 male, n = 10 female). We also considered whether exposure occurred either abruptly at high concentrations through a contamination event (“disaster exposure”) or chronically at low concentrations (“non-disaster exposure”). There were 8 studies that compared associations between dioxin/DL-PCB exposure and diabetes risk in males versus females within the same population. When all sex-stratified or single-sex studies were considered in the meta-analysis (n = 18), the summary relative risk (RR) for incident diabetes among those exposed relative to reference populations was 1.78 (95% CI = 1.37–2.31) and 1.95 (95% CI = 1.56–2.43) for female and males, respectively. However, when we restricted the meta-analysis to disaster-exposed populations, the RR was higher in females than males (2.86 versus 1.59, respectively). In contrast, in non-disaster exposed populations the RR for females was lower than males (1.40 and 2.02, respectively). Our meta-analysis suggests that there are sex differences in the associations between dioxin/DL-PCBs exposure and incident diabetes, and that the mode of exposure modifies these differences.

Health risk assessment of exposure to organochlorine pesticides in the general population in Seoul, Korea over 12 years: A cross-sectional epidemiological study

This study evaluated the 12-year trends in serum levels of 28 organochlorine pesticides (OCPs) in 880 adults living in Seoul, Korea. The OCP levels decreased from 2006 to 2017, and p,p'-dichlorodiphenyldichloroethylene was a predominant compound. OCP levels were higher in females than in males, and showed positive associations with BMI and age. The OCP concentrations had inverted U-shaped associations with low-density lipoprotein cholesterol and total cholesterol. Concentrations of β-hexachlorocyclohexane were significantly higher in patients with hypertension than in participants that were normotensive. OCP levels showed positive associations with uric acid, creatinine, and thyroid-stimulating hormone, but negative associations with free thyroxine. Participants with diabetes had significantly higher OCP levels than those without it. Principal component analysis suggested possible differences in disease manifestation depending on the composition of OCPs. These results suggest that OCPs might disturb renal transport and thyroid homeostasis. To our knowledge, the inverted U-shaped associations of heptachlor epoxide and endosulfan with cholesterol, the epidemiological associations of trans-nonachlor and endosulfan with thyroid hormones, and the association of p,p'-DDE with hyperuricemia have not been previously reported in general population. This is the first long-term study to show trends of 28 OCPs in serum and associations with various health indicators in Korea.

Endrin potentiates early-stage adipogenesis in 3T3-L1 cells by activating the mammalian target of rapamycin

Obesogens are a type of endocrine-disrupting chemicals (EDCs) that disrupt the human endocrine system, resulting in obesity and metabolic disease. Several obesogens, including bisphenol A, tolylfluanid, and some pesticides, have been identified and studied previously; however, the underlying molecular mechanisms by which obesogens interfere with adipogenesis and induce insulin resistance in adipocyte remain unknown. This study aims to determine which type of chemical is the most potent obesogen and to investigate its effect on adipogenesis-related gene expressions. 3T3-L1, a pre adipocyte cell line, was differentiated into mature adipocytes with either vehicle or various obesogens, including bisphenol A, tolylfluanid, and endrin, as well as corticosterone, at the same dose. Subsequently, intracellular and secreted triglyceride levels were measured, and the expression of genes and proteins involved in adipogenesis and lipogenesis was investigated. We found that endrin was the most potent regulator of adipogenic differentiation, as compared to tolylfluanid, bisphenol A, and corticosterone. Endrin increased intracellular and secreted triglyceride levels and enhanced the expression of adipogenic transcription factors as well as the terminal differentiation marker in a dose-dependent manner. During the early stages of differentiation, endrin enhanced mammalian target of rapamycin (mTOR) activity, which was suppressed by the pharmacological blockade of the protein kinase B-mTOR pathway, with repressed adipogenic differentiation. However, endrin did not change the expression levels of the downstream members of the mTOR signaling pathway or proteins related to lipolysis in response to insulin. Thus, we suggest that endrin potentiates early-stage adipogenic differentiation by activating the mTOR pathway.

Chlordane exposure causes developmental delay and metabolic disorders in Drosophila melanogaster

The incidence of metabolic diseases is increasing every year, and several studies have highlighted the activity of persistent organic pollutants (POPs) in causing hyperlipidemia and diabetes, and these compounds are considered to be endocrine disrupting chemicals (EDCs). Chlordane is classified as an endocrine disruptor, but the mechanism of how it functions is still unclear. This study investigates the effects of chlordane exposure on Drosophila larvae. Drosophila was cultured in diet containing 0.01 μM, 0.1 μM, 1 μM, 5 μM, and 10 μM chlordane, and the toxicity of chlordane, the growth and development of Drosophila, the homeostasis of glucose and lipid metabolism and insulin signaling pathway, lipid peroxidation-related indicators and Nrf2 signaling pathway were evaluated. We here found that exposure to high concentrations of chlordane decreased the survival rate of Drosophila and that exposure to low concentrations of chlordane caused disruption of glucose and lipid metabolism, increased insulin secretion and impairment of insulin signaling. Notably, it also led to massive ROS production and lipid peroxidation despite of the activation of Nrf2 signaling pathway, an important pathway for maintaining redox homeostasis. Collectively, chlordane causes lipid peroxidation and disrupts redox homeostasis, which may be a potential mechanism leading to impaired insulin signaling and the metabolism of glucose and lipid, ultimately affects Drosophila development.

Exposure to novel and legacy per- and polyfluoroalkyl substances (PFASs) and associations with type 2 diabetes: A case-control study in East China

Associations between per- and polyfluoroalkyl substances (PFASs) and the incidence of type 2 diabetes are controversial in epidemiological studies. In addition, limited data are available for assessing the health effects of novel PFAS alternatives. Our study evaluated the effects of PFAS exposure on type 2 diabetes by estimating the associations of PFASs in human serum with the risk of type 2 diabetes and levels of glycemic biomarkers and lipid fractions. The case-control study consisted of 304 participants from Shandong Province, East China, half of which were diagnosed with type 2 diabetes. Logistic regression showed that most PFASs were inversely associated with the risk of type 2 diabetes after adjusting for age, sex, and body mass index. However, concentrations of perfluorooctanoic acid (PFOA) in the control group were positively associated with fasting plasma glucose levels (β = 0.04, 95% confidence interval (CI): 0.0003, 0.08), which may promote the development of type 2 diabetes. Furthermore, each log-unit increase in the concentrations of perfluorononanoic acid (PFNA), perfluoroundecanoic acid (PFUnDA), and 6:2 chlorinated polyfluoroalkyl ether sulfonic acid (Cl-PFESA) were associated with a total cholesterol increase (i.e., 17.49% (95% CI: 0.93%, 34.90%), 17.49% (95% CI: 4.71%, 31.83%), and 17.49% (95% CI: 4.71%, 31.83%), respectively). Positive associations were also observed between PFNA, PFUnDA, perfluorooctane sulfonate (PFOS), and 6:2 Cl-PFESA and low-density lipoprotein cholesterol. However, no associations between PFASs and hemoglobin A1c, triglycerides, or high-density lipoprotein cholesterol reached statistical significance, nor associations between PFAS mixtures and outcomes of interest. In conclusion, the significant correlations between serum PFASs and glycemic biomarkers and lipid fractions indicated that PFAS exposure may be a potential diabetogenic factor. To the best of our knowledge, this is the first study to assess the associations between novel Cl-PFESAs and type 2 diabetes, although the inverse associations observed require clarification in future studies.

Persistent exercise fatigue and associative learning deficits in combination with transient glucose dyshomeostasis in a GWI mouse model

Aims:

To characterize exercise fatigue, metabolic phenotype and cognitive and mood deficits correlated with brain neuroinflammatory and gut microbiome changes in a chronic Gulf War Illness (GWI) mouse model. The latter have been described in an accompanying paper [1].

Main methods:

Adult male C57Bl/6N mice were exposed for 28 days (5 days/week) to pyridostigmine bromide: 6.5 mg/kg, b.i.d., P.O. (GW1) or 8.7 mg/kg, q.d., P.O. (GW2); topical permethrin (1.3 mg/kg in 100% DMSO) and N,N-diethyl-meta-toluamide (DEET 33% in 70% EtOH) and restraint stress (5 min). Exercise, metabolic and behavioral endpoints were compared to sham stress control (CON/S).

Key findings:

Relative to CON/S, GW2 presented persistent exercise intolerance (through post-treatment (PT) day 161), deficient associative learning/memory, and transient insulin insensitivity. In contrast to GW2, GW1 showed deficient long-term object recognition memory, milder associative learning/memory deficit, and behavioral despair.

Significance:

Our findings demonstrate that GW chemicals dose-dependently determine the presentation of exercise fatigue and severity/type of cognitive/mood-deficient phenotypes that show persistence. Our comprehensive mouse model of GWI recapitulates the major multiple symptom domains characterizing GWI, including fatigue and cognitive impairment that can be used to more efficiently develop diagnostic tests and curative treatments for ill Gulf War veterans.

1,1,1-trichloro-2,2-bis (p-chlorophenyl)-ethane (DDT) and 1,1-Dichloro-2,2-bis (p, p'-chlorophenyl) ethylene (DDE) as endocrine disruptors in human and wildlife: A possible implication of mitochondria

1,1,1-trichloro-2,2-bis (p-chlorophenyl)-ethane (DDT) and its main metabolite 1,1-Dichloro-2,2-bis (p, p'-chlorophenyl) ethylene (DDE) act as endocrine disruptors in humans and wildlife. Immunomodulatory functions have also been attributed to both xenobiotics. DDT was banned in the 1970s due to its toxicity, but it is still produced and used for indoor residual spraying with disease vector control purposes. Due to their persistence and lipophilic properties, DDT and DDE can bioaccumulate through the food chain, being stored in organisms' adipose depots. Their endocrine disruptor function is mediated by agonist or antagonist interaction with nuclear receptors. Present review aimed to provide an overview of how DDT and DDE exposure impacts reproductive and immune systems with estrogen-disrupting action in humans and wildlife. Studies showing DDT and DDE impact on mitochondrial function and apoptosis pathway will also be reviewed, suggesting the hypothesis of direct action on mitochondrial steroid receptors.

Nonmonotonic response of type 2 diabetes by low concentration organochlorine pesticide mixture: Findings from multi-omics in zebrafish

Exposure to a single organochlorine pesticide (OCP) at high concentration and over a short period of exposure constrain our understanding of the contribution of chemical exposure to type 2 diabetes (T2D). A total of 450 male and female zebrafish was exposed to mixtures of five OCPs at 0, 0.05, 0.25, 2.5, and 25 μg/L for 12 weeks. T2D-related hematological parameters (i.e., glucose, insulin, free fatty acid, and triglycerides) and mitochondrial complex I to IV activities were assessed. Metabolomics, proteomics, and transcriptomics were analyzed in female livers, and their data-driven integration was performed. High fasting glucose and low insulin levels were observed only at 0.05 μg/L of the OCP mixture in females, indicating a nonlinear and sexually dependent response. We found that exposure to the OCP mixture inhibited the activities of mitochondrial complexes, especially III and IV. Combining individual and integrated omics analysis, T2D-linked metabolic pathways that regulate mitochondrial function, insulin signaling, and energy homeostasis were altered by the OCP mixture, which explains the observed phenotypic hematological effects. We demonstrated the cause-and-effect relationship between exposures to OCP mixture and T2D using zebrafish model. This study gives an insight into mechanistic research of metabolic diseases caused by chemical exposure using zebrafish.

Investigation of the association between pesticide exposure and the prevalence of type 2 diabetes in Shahedieh population in Yazd

This study aimed to investigate the effect of exposure to pesticides and the prevalence of type 2 diabetes (T2D). In a cross-sectional study with a population of 9088, the data were collected through Persian Adult Cohort Questionnaire in Shahedieh area of Yazd, Iran. Based on the results, variables such as age, gender, body mass index, physical activity, and education level in the studied population had a significant association with the prevalence of diabetes. Although the obtained data in this study did not show a relationship between exposure to pesticides and the risk of developing T2D, further prospective studies are needed to determine the association between exposure to pesticides and the development of T2D.

Exposure to a low concentration of mixed organochlorine pesticides impairs glucose metabolism and mitochondrial function in L6 myotubes and zebrafish

More realistic effects on glucose metabolic dysfunction can be evaluated by applying organochlorine (OCP) mixtures than individual OCPs. We formulated an equal ratio mixture of five OCPs (chlordane, heptachlor, p,p'-dichlorodiphenyltrichloroethane, β-hexachlorocyclohexane, and hexachlorobenzene) and treated L6 myotubes with this OCP mixture to investigate effects on glucose uptake and the underlying mechanism. Exposure to the OCP mixture reduced 2-NBDG staining, representing glucose uptake, and stimulated the excessive production of reactive oxygen species (ROS). Reduced 2-NBDG uptake and ROS overproduction were compensated by insulin treatment. The expression of proteins such as IRβ, PI3K, and AKT was downregulated, indicating that ROS overproduction contributed to the inhibition of insulin-dependent glucose uptake. Reduction in mitochondria quantity and decreased expression levels of PGC-1α, PDH, and GLUT4 proteins were observed, suggesting that mitochondrial dysfunction played a causative role in the disruption of glucose uptake. The inhibition of glucose uptake and ROS overproduction caused by the OCP mixture were also found in zebrafish as an in vivo model. We demonstrated that exposure to the OCP mixture, even at the lowest concentration, perturbed glucose uptake, which was associated with mitochondrial dysfunction, suggesting that an OCP mixture could be a potential environmental factor in type 2 diabetes-related effects on skeletal muscles.

The association between environmental exposures to chlordanes, adiposity and diabetes-related features: a systematic review and meta-analysis

Chlordane compounds (CHLs) are components of technical chlordane listed in the Stockholm convention on persistent organic pollutants identified as endocrine disrupting chemicals (EDCs) and may interfere with hormone biosynthesis, metabolism or action resulting in an unbalanced hormonal function. There is increasing scientific evidence showing EDCs as risk factors in the pathogenesis and development of obesity and obesity-related metabolic syndromes such as type 2 diabetes, but there is no systematized information on the effect of CHLs in humans. Our aim is to identify the epidemiological data on the association between CHLs with adiposity and diabetes using a systematic approach to identify the available data and summarizing the results through meta-analysis. We searched PubMed and Web of Science from inception up to 15 February 2021, to retrieve original data on the association between chlordanes, and adiposity or diabetes. For adiposity, regression coefficients and Pearson or Spearman correlation coefficients were extracted and converted into standardized regression coefficients. Data were combined using fixed effects meta-analyses to compute summary regression coefficients and corresponding 95% confidence intervals (95% CI). For the association between chlordanes and diabetes, Odds ratios (ORs) were extracted and the DerSimonian and Laird method was used to compute summary estimates and respective 95% CI. For both, adjusted estimates were preferred, whenever available. Among 31 eligible studies, mostly using a cross-sectional approach, the meta-analysis for adiposity was possible only for oxychlordane and transchlordane, none of them were significantly associated with adiposity [(β = 0.04, 95% CI 0.00; 0.07, I² = 89.7%)] and (β = 0.02, 95% CI − 0.01; 0.06), respectively. For diabetes, the estimates were positive for all compounds but statistically significant for oxychlordane [OR = 1.96 (95% CI 1.19; 3.23)]; for trans-nonachlor [OR = 2.43 (95% CI 1.64; 3.62)] and for heptachlor epoxide [OR = 1.88 (95% CI 1.42; 2.49)]. Our results support that among adults, the odds of having diabetes significantly increase with increasing levels of chlordanes. The data did not allow to reach a clear conclusion regarding the association with adiposity.

Level of Organochlorine Pesticide in Prediabetic and Newly Diagnosed Diabetes Mellitus Patients with Varying Degree of Glucose Intolerance and Insulin Resistance among North Indian Population

BACKGROUND

Organochlorine pesticides (OCPs) exposure may induce an endocrine disruption which may lead to the risk of developing diabetes through alteration and disturbance of glucose metabolism, insulin resistance, and destruction of β-cells. The present study determines the recent trend of OCPs residue in blood samples and their association with the known risk factors responsible for developing the risk of diabetes among the North Indian population.

METHODS

Blood sample of 300 patients (100 each of normal glucose tolerance [NGT], prediabetes and newly detected diabetes mellitus [DM]) between the age group of 30 to 70 years were collected. OCPs residue in whole blood samples was analyzed by using gas chromatography equipped with a 63Ni selective electron capture detector.

RESULTS

Significantly higher levels of β-hexachlorocyclohexane (HCH), dieldrin, and p,p'-dichloro-diphenyl-dichloroethylene (DDE) were found in the prediabetes and newly detected DM groups as compared to NGT group. Insulin resistance showed to be significantly positive correlation with β-HCH and dieldrin. Also, fasting and postprandial glucose levels were significantly positively correlated with levels of β-HCH, dieldrin, and p,p'-DDE. Further, when OCPs level was adjusted for age and body mass index (BMI), it was found that β-HCH, dieldrin, and p,p'-DDE levels in blood increases the risk of diabetes by 2.70, 2.83, and 2.55 times respectively. Moreover, when we adjust OCPs level based on BMI categories (BMI <23, ≥23, and ≤25, and >25 kg/m2); β-HCH and p,p'-DDE showed a significant risk of developing newly detected DM with BMI >25 and ≥23 and ≤25 kg/m2.

CONCLUSION

The OCPs level present in the environment may be responsible for biological, metabolic, and endocrine disruptions within the human body which may increase the risk of developing newly detected DM. Hence, OCPs exposure can play a crucial role in the etiology of diabetes.

Persistent organic pollutants-environmental risk factors for diabetes mellitus? - A population-based study

BACKGROUND

Globally, type-2 diabetes mellitus is increasing in epidemic proportions. A major cause of concern in India is the increasing incidence of cases, especially troubling is the observed increase in younger age groups with no risk factors. New evidence suggests that many environmental factors, such as air pollution, persistent organic pollutants (POPs), and environmental estrogens are implicated as risk factors for type-2 diabetes mellitus. Animal and human epidemiological studies have shown ubiquitous lipophilic substances, including POPs, are frequently associated with type-2 diabetes mellitus. Such studies have not been undertaken in Indian youth.

METHODS

This is a cross-sectional study that explored the association between POPs and type-2 diabetes mellitus in Indian urban and rural population. About 7 ml of venous blood was collected from all consenting patients and serum was separated immediately and was transported to the lab for further analysis. Serum levels of POPs, including organochlorine (OC) compounds and organophosphorus pesticides, were estimated using sample gas chromatography-mass spectrometry (GC-MS). The fasting blood sugar values and the serum levels of POPS were tested using Pearson correlation coefficient. The magnitude of increase in blood sugar corresponding to increase in POPs was analyzed using linear regression analysis. The odds ratios (ORs) were expressed at 95% confidence intervals (CIs).

RESULTS

Three OC pesticides and one organophosphate pesticide were strongly associated with increasing blood sugar levels after adjusting for age, sex, and body mass index - lindane (OR 4.95, 95% CI 1.03-23.73), DDT o, p' (OR 3.50, 95% CI 1.04-11.73), dimethoate (OR 19.31, 95% CI 4.22-88.37), and dichlorvas (OR 6.33, 95% CI 1.28-31.18).

Gut microbiota-mediated pesticide toxicity in humans: Methodological issues and challenges in the risk assessment of pesticides

Many in vivo and in vitro studies have shown that pesticides can disrupt the functioning of gut microbiota (GM), which can lead to many diseases in humans. While the tests developed by the Organization of Economic Cooperation and Development (OECD) are expected to capture most apical effects resulting from GM disruptions, exclusion of GM in the risk assessment might mischaracterize hazards or overestimate/underestimate risks, especially when extrapolating results from one species to another species or population with a substantially different GM. On the other hand, direct assessment of GM-mediated effects may face challenges in identifying hazards, since not all GM perturbations will lead to human adverse effects. In this regard, reliable and validated biomarkers for common GM-mediated adverse effects may be very useful in the identification of GM-mediated pesticide toxicity. Nevertheless, proving causality of GM-mediated effects will need modifications of Bradford Hill criteria as well as Koch's postulates, which are more suitable for the "one-pathogen" paradigm. Furthermore, risk assessment of GM-mediated effects may require pesticide toxicokinetics along the gut, possibly through modeling, and the establishment of the involvement of GM in the mechanism of action (MOA) of the pesticide. Risk assessment of GM mediated effects also requires the standardization of experimental approaches as well as the establishment of microbial reference communities, since variations exist among GM in human populations.

Chronic oral exposure to pesticides and their consequences on metabolic regulation: role of the microbiota

Pesticides have long been used in agriculture and household treatments. Pesticide residues can be found in biological samples for both the agriculture workers through direct exposure but also to the general population by indirect exposure. There is also evidence of pesticide contamination in utero and trans-generational impacts. Whilst acute exposure to pesticides has long been associated with endocrine perturbations, chronic exposure with low doses also increases the prevalence of metabolic disorders such as obesity or type 2 diabetes. Dysmetabolism is a low-grade inflammation disorder and as such the microbiota plays a role in its etiology. It is therefore important to fully understand the role of microbiota on the genesis of subsequent health effects. The digestive tract and mostly microbiota are the first organs of contact after oral exposure. The objective of this review is thus to better understand mechanisms that link pesticide exposure, dysmetabolism and microbiota. One of the key outcomes on the microbiota is the reduced Bacteroidetes and increased Firmicutes phyla, reflecting both pesticide exposure and risk factors of dysmetabolism. Other bacterial genders and metabolic activities are also involved. As for most pathologies impacting microbiota (including inflammatory disorders), the role of prebiotics can be suggested as a prevention strategy and some preliminary evidence reinforces this axis.

High levels of organochlorine pesticides in drinking water as a risk factor for type 2 diabetes: A study in north India

Organochlorine pesticides (OCPs) are well known synthetic pesticides widely used in agricultural practices and public health program. Higher toxicity, slow degradation, and bioaccumulation are the significant challenges of OCPs. Due to its uses in agricultural and public health, contamination of drinking water and water table also increases day by day. Contaminated drinking water has become a significant issue and alarming signal for public health globally. The purpose of this study was to assess the recent trend of organochlorine pesticides (OCPs) level in drinking water and blood samples of the North Indian population and also to find out its association with glucose intolerance, lipid metabolism, and insulin resistance, which are known risk factors of type 2 diabetes mellitus (T2DM). A case-control study was conducted on 130 Non-Glucose intolerance (NGT), 130 pre-diabetes and 130 recently diagnosed T2DM subjects of the age group of 30-70 years. Patients consuming drinking water from the same source for at least ten years were included in this study for blood and water samples collection. Significantly higher levels of α-HCH, β-HCH, γ-HCH, p,p'-DDE, and o,p'-DDT were found in groundwater samples. However, in tap water samples, the level of α-HCH was found to be slightly higher than the permissible limit of 0.001. Among all recruited subjects consuming contaminated groundwater, 42% had T2DM, 38% pre-diabetes, and the remaining 20% were found normal. We also observed that OCP contamination in groundwater is higher than tap and filter water. The levels of β-HCH, p,p'-DDE, and o,p'-DDT were higher in the pre-diabetes and T2DM group than the NGT group. With an increase of OCPs level in groundwater, the blood OCPs level tends to increase T2DM risk. It depicts that the elevated OCPs level in consumed groundwater may contribute to increased risk for the development of T2DM after a certain period of exposure.

Is Technical-Grade Chlordane an Obesogen?

The prevalence of obesity has tripled in recent decades and is now considered an alarming public health problem. In recent years, a group of endocrine disruptors, known as obesogens, have been directly linked to the obesity epidemic. Its etiology is generally associated with a sedentary lifestyle, a high-fat diet and genetic predisposition, but environmental factors, such as obesogens, have also been reported as contributors for this pathology. In brief, obesogens are exogenous chemical compounds that alter metabolic processes and/or energy balance and appetite, thus predisposing to weight gain. Although this theory is still recent, the number of compounds with suspected obesogenic activity has steadily increased over the years, though many of them remain a matter of debate. Technical-grade chlordane is an organochlorine pesticide widely present in the environment, albeit at low concentrations. Highly lipophilic compounds can be metabolized by humans and animals into more toxic and stable compounds that are stored in fat tissue and consequently pose a danger to the human body, including the physiology of adipose tissue, which plays an important role in weight regulation. In addition, technical-grade chlordane is classified as a persistent organic pollutant, a group of chemicals whose epidemiological studies are associated with metabolic disorders, including obesity. Herein, we discuss the emerging roles of obesogens as threats to public health. We particularly discuss the relevance of chlordane persistence in the environment and how its effects on human and animal health provide evidence for its role as an endocrine disruptor with possible obesogenic activity.

Association between type 2 diabetes and exposure to chlorinated persistent organic pollutants in Algeria: A case-control study

BACKGROUND

The prevalence of type 2 diabetes is alarmingly increasing around the world and its impact exceeds the predictions made by WHO in the early 2000s. Today there is growing scientific evidence that exposure to endocrine disruptors and mainly POPs can contribute to the development of type 2 diabetes. The main objective of this case-control study is to assess the link between the plasma levels of certain chlorinated persistent organic pollutants, and the prevalence of type 2 diabetes in the general population of Algeria.

MATERIAL AND METHOD

The study was conducted on 361 subjects, to whom the plasma levels of selected biomarkers were determined on GC-MS. A logistic regression was performed to examine the prevalence of diabetes in the POPs categories, considering sex, age, BMI, family history of diabetes, smoking and hypertension.

RESULTS

Diabetic subjects had higher plasma concentrations of POPs than non-diabetic subjects. After adjusting for the known risk factors for type 2 diabetes in Algeria, the risk expressed in OR (95% CI) was 12.58 (4.76-33.26) for 4,4'DDE, 3.69 (1.90-7.15) for HCB and 2.28 (1.20-4.39) PCB153. PCB138 and PCB180 showed no significant risk.

CONCLUSION

This study found that environmental exposure to some POPs is associated with an increased risk of type 2 diabetes in the studied sample.

Effects of incremental endosulfan sulfate exposure and high fat diet on lipid metabolism, glucose homeostasis and gut microbiota in mice

The influence of pollutants on metabolic diseases such as type 2 diabetes mellitus is an emerging field in environmental medicine. Here, we explored the effects of a low-dose endosulfan sulfate (ES), a major metabolite of the pesticide endosulfan and a bio-persistent contaminant detected in environmental and human samples, on the progress of obesity and metabolic disorders. Pregnant CD-1 mice were given ES from gestational day 6 to postnatal day 21 (short-term). After weaning, male pups of exposed dams were provided with a low-fat or a high-fat diet (LFD or HFD) and assessed after an additional 12 weeks. At the same time, one group of male pups continuously received ES (long-term). Treatment with low-dose ES, short or long-term, alleviated the development of obesity and accumulation of hepatic triglycerides induced by HFD. Analysis of gene expression, metabolic profile and gut microbiome indicates that ES treatment inhibits adipogenesis induced by HFD due to enhanced lipid catabolism, fatty acid oxidation and disturbance of gut microbiota composition. However, impaired glucose and insulin homeostasis were still conserved in HFD-fed mice exposed to ES. Furthermore, ES treatment impaired glucose tolerance, affected hepatic gene expression, fatty acids composition and serum metabolic profile, as well as disturbed gut microbiota in LFD-fed mice. In conclusion, ES treatment at levels close to the accepted daily intake during fetal development directly impact glucose homeostasis, hepatic lipid metabolism, and gut microbiome dependent on the type of diet consumed. These findings provide a better understanding of the complex interactions of environmental pollutants and diet at early life stages also in the context of metabolic disease.

Biomarkers of metabolic disorders and neurobehavioral diseases in a PCB- exposed population: What we learned and the implications for future research

Polychlorinated biphenyls (PCBs) are one of the original twelve classes of toxic chemicals covered by the Stockholm Convention on Persistent Organic Pollutants (POP), an international environmental treaty signed in 2001. PCBs are present in the environment as mixtures of multiple isomers at different degree of chlorination. These compounds are manmade and possess useful industrial properties including extreme longevity under harsh conditions, heat absorbance, and the ability to form an oily liquid at room temperature that is useful for electrical utilities and in other industrial applications. They have been widely used for a wide range of industrial purposes over the decades. Despite a ban in production in 1979 in the US and many other countries, they remain persistent and ubiquitous in environment as contaminants due to their improper disposal. Humans, independent of where they live, are therefore exposed to PCBs, which are routinely found in random surveys of human and animal tissues. The prolonged exposures to PCBs have been associated with the development of different diseases and disorders, and they are classified as endocrine disruptors. Due to its ability to interact with thyroid hormone, metabolism and function, they are thought to be implicated in the global rise of obesity diabetes, and their potential toxicity for neurodevelopment and disorders, an example of gene by environmental interaction (GxE). The current review is primarily intended to summarize the evidence for the association of PCB exposures with increased risks for metabolic dysfunctions and neurobehavioral disorders. In particular, we present evidence of gene expression alterations in PCB-exposed populations to construct the underlying pathways that may lead to those diseases and disorders in course of life. We conclude the review with future perspectives on biomarker-based research to identify susceptible individuals and populations.

Exposure to organochlorine pesticides and the risk of type 2 diabetes in the population of East China

Organochlorine pesticides (OCPs) have been reported to be associated with an elevated risk of type 2 diabetes, although no study has focused on such associations in Chinese populations. In this case-control study, we aimed to explore the associations between OCPs and type 2 diabetes and their potential mechanisms in a population from East China. Participants diagnosed with type 2 diabetes and nondiabetic participants from Shandong Province, East China, were enrolled in this case-control study. Six OCPs (β-HCH, trans-chlordane, trans-nonachlor, p,p'-DDE, p,p'-DDT and mirex/kepone) were detected in more than 75% of serum samples. Logistic regression analysis and multiple linear regression analysis were used to assess the associations between OCP exposure and the outcomes. After adjusting for potential confounding factors such as age, sex and body mass index, all six OCPs showed positive associations with type 2 diabetes in a linear dose-response manner. Serum concentrations of β-HCH and p,p'-DDE were associated with higher levels of fasting plasma glucose in participants without diabetes, although no OCPs showed significant associations with hemoglobin A1c. In addition, certain OCPs showed significantly positive associations with triglycerides, total cholesterol, and low-density lipoprotein cholesterol and negative relationships with high-density lipoprotein cholesterol in nondiabetics, indicating that OCP exposure may disrupt lipid metabolism. Findings in the current study indicated that OCPs may be a diabetogenic factor in the population of this study. To our knowledge, this is the first study to investigate the associations between OCP exposure and type 2 diabetes in a Chinese population.

Associations between the exposure to persistent organic pollutants and type 2 diabetes in East China: A case-control study

Persistent organic pollutants (POPs) have been associated with a high risk of type 2 diabetes in different regions, although few studies from China have been published. We aimed to investigate the associations between POP exposure and type 2 diabetes in Chinese population. A total of 158 participants diagnosed with type 2 diabetes and 158 participants without the disorder from Shandong Province were enrolled in this case-control study during 2016-2017. Nine polychlorinated biphenyl congeners (PCBs) and 2 polybrominated diphenyl ethers with detectable levels in ≥75% of the participants were selected for data analysis. The results showed that POP exposure was significantly and positively associated with the risk of diabetes after adjusting for age, sex, BMI, triglycerides and total cholesterol. However, we did not observe an obvious modified effect of adiposity on the associations between POP exposure and diabetes in the present study, as strong associations between POPs and diabetes were observed in both the higher-BMI (BMI≥25 kg/m²) and the lower-BMI (BMI<25 kg/m²) groups. POPs showed stronger associations with diabetes in males than in females. The odds ratio (OR) for the highest quartile of ∑POPs was 6.97 for males, nearly two times higher than that for females (OR = 3.58). All these findings suggest that POP exposure may impact the risk of diabetes in Chinese population.

Diabetes and Parkinson's Disease: Debating the Link Through Ca2+/cAMP Signalling

BACKGROUND

A link between diabetes and Parkinson´s disease (PD) has been established by several reports. Consistent data report that people diagnosed with diabetes have demonstrated an enhanced risk of manifesting PD in their lifetime. The working principles involved in this link have been extensively discussed. Over the last decade, diabetes has been reported to be correlated with an increased risk of dementia, suggesting a potential role of diabetes, or insulin signalling dysregulations, in neurodegeneration. In addition, it is nowadays highly debated that dysregulations related to Ca2+ signalling may be an upstream issue which could also link diabetes and PD. Ca2+ and cAMP signalling pathways (Ca2+/cAMP signalling) control both the neurotransmitters/hormones release and neuronal death.

CONCLUSION

Considering our previous reports about Ca2+/cAMP signalling, the putative contribution of Ca2+/cAMP signalling in this link (between diabetes and PD) is discussed in this paper.

A study of risk factors for the possible cases of acute occupational pesticide poisoning of orchard farmers in some parts of south Chungcheong province

BACKGROUND

The objective of the present study is to identify differences in the prevalence of acute occupational pesticide poisoning across Korean orchard farmers' farming characteristics and the risk factors that have an effect on acute occupational pesticide poisoning.

METHODS

For 3 years (2014, 2015, and 2017), a questionnaire survey was conducted on 394 orchard farmers in some parts of south Chungcheong Province in relation to pesticide poisoning. 323 orchard farmers who responded to acute occupational pesticide poisoning were included for final analysis. With acute occupational pesticide poisoning as the dependent variable, a χ2 test and a multiple logistic regression analysis were conducted.

RESULTS

The results of the prevalence of acute occupational pesticide poisoning across farming characteristics showed that the group wearing 4 or more pesticide personal protective equipment (PPE) had a lower prevalence of acute occupational pesticide poisoning than the group wearing 3 or less pesticide PPE (p < 0.05). Furthermore, an analysis by area of fruit farming revealed that the group with more than 12,000m2 in the area of fruit farming had a higher prevalence of acute occupational pesticide poisoning (p < 0.05). Orchard farmers mainly use a speed sprayer to spray pesticides, and the speed sprayer can be categorized by presence of cabin. The analysis of the prevalence of acute occupational pesticide poisoning by speed sprayer's cabin existence found that existence of speed sprayer's cabin did not show a statistically significant difference in the prevalence of acute occupational pesticide poisoning.

CONCLUSIONS

The present study analyzed the prevalence of acute occupational pesticide poisoning depending on the speed sprayer's cabin existence and found no significant difference. The fact that famers using the cabinless style speed sprayer shows a higher percentage in wearing PPE than those using the cabin style speed sprayer is suggested to elucidate the result. As the first study in Korea which examined the prevalence of acute occupational pesticide poisoning by speed sprayer's cabin existence, the present study proposes the expected effect that increase of wearing pesticide PPE along with employ of speed sprayer's cabin can reduce the prevalence of acute occupational pesticide poisoning among orchard farmers.

Tea consumption and risk of diabetes in the Chinese population: a multi-centre, cross-sectional study

The aim of the present study was to explore the influence of tea consumption on diabetes mellitus in the Chinese population. This multi-centre, cross-sectional study was conducted in eight sites from south, east, north, west and middle regions in China by enrolling 12 017 subjects aged 20–70 years. Socio-demographic and general information was collected by a standardised questionnaire. A standard procedure was used to measure anthropometric characteristics and to obtain blood samples. The diagnosis of diabetes was determined using a standard 75-g oral glucose tolerance test. In the final analysis, 10 825 participants were included and multiple logistic models and interaction effect analysis were applied for assessing the association between tea drinking with diabetes. Compared with non-tea drinkers, the multivariable-adjusted OR for newly diagnosed diabetes were 0·80 (95 % CI 0·67, 0·97), 0·88 (95 % CI 0·71, 1·09) and 0·86 (95 % CI 0·67, 1·11) for daily tea drinkers, occasional tea drinkers and seldom tea drinkers, respectively. Furthermore, drinking tea daily was related to decreased risk of diabetes in females by 32 %, elderly (>45 years) by 24 % and obese (BMI > 30 kg/m2) by 34 %. Moreover, drinking dark tea was associated with reduced risk of diabetes by 45 % (OR 0·55; 95 % CI 0·42, 0·72; P < 0·01). The results imply that drinking tea daily was negatively related to risk of diabetes in female, elderly and obese people. In addition, drinking dark tea was associated with decreased risk of type 2 diabetes mellitus.

Technical-grade chlordane compromises rat Sertoli cells proliferation, viability and metabolic activity

Environmental contaminants are a daily presence in human routine. Multiple studies highlight the obesogenic activity of some chemicals. Moreover, these compounds have been suggested as a cause of male subfertility and/or infertility. Technical-grade chlordane (TGC) is classified as an endocrine-disruptor chemical, while its classification as obesogen is controversial. Herein, we studied the influence of TGC on Sertoli cells (SCs) metabolism. Rat Sertoli cells (rSCs) were cultured without and in the presence of increasing concentrations (1, 10 and 1000 nM) of TGC. The viability, proliferation, metabolic activity and the metabolic profile of rSCs was assessed. Expression of key glycolysis-related enzymes, transporters and biomarkers of oxidative damage were also evaluated. Our results show that exposure to higher concentrations of TGC decreases SCs proliferation and viability, which was accompanied by increased glucose consumption associated with an upregulation of Glut3 levels. As a result, pyruvate/lactate production were enhanced thus increasing the glycolytic flux in cells exposed to 1000 nM TGC, although lactate dehydrogenase expression and activity did not increase. Notably, biomarkers associated with oxidative damage remained unchanged after exposure to TGC. This is the first report showing that TGC alters glucose rSCs metabolism and the nutritional support of spermatogenesis with consequences for male fertility.

A dual mixture of persistent organic pollutants modifies carbohydrate metabolism in the human hepatic cell line HepaRG

Individuals as well as entire ecosystems are exposed to mixtures of Persistent Organic Pollutants (POPs). Previously, we showed, by a non-targeted approach, that the expression of several genes involved in carbohydrate metabolism was almost completely inhibited in the human hepatic cell line HepaRG following exposure to a mixture of the organochlorine insecticide alpha-endosulfan and 2,3,7,8 tetrachlorodibenzo-p-dioxin. In this European HEALS project, which studies the effects of the exposome on human health, we used a Physiologically Based BioKinetic model to compare the concentrations previously used in vitro with in vivo exposures for humans. We investigated the effects of these POPs on the levels of proteins, on glycogen content, glucose production and the oxidation of glucose into CO₂ and correlated them to the expression of genes involved in carbohydrate metabolism as measured by RT-qPCR. Exposure to individual POPs and the mixture decreased the expression of the proteins investigated as well as glucose output (up to 82%), glucose oxidation (up to 29%) and glycogen content (up to 48%). siRNAs that specifically inhibit the expression of several xenobiotic receptors were used to assess receptor involvement in the effects of the POPs. In the HepaRG model, we demonstrate that the effects are mediated by the aryl hydrocarbon receptor and the estrogen receptor alpha, but not the pregnane X receptor or the constitutive androstane receptor. These results provide evidence that exposure to combinations of POPs, acting through different signaling pathways, may affect, more profoundly than single pollutants alone, metabolic pathways such as carbohydrate/energy metabolism and play a potential role in pollutant associated metabolic disorders.

Beneficial role of vanillin, a polyphenolic flavoring agent, on maneb-induced oxidative stress, DNA damage, and liver histological changes in Swiss albino mice

Vanillin, a widely used flavoring agent, has antimutagenic and antioxidant properties. The current study was performed to evaluate its beneficial role against hepatotoxicity induced by maneb, a dithiocarbamate fungicide. Mice were divided into four groups of six each: group 1, serving as negative controls which received by intraperitoneal way only distilled water, a solvent of maneb; group 2, received daily, by intraperitoneal way, maneb (30 mg kg^-1 body weight (BW)); group 3, received maneb at the same dose of group 2 and 50 mg kg^-1 BW of vanillin by intraperitoneal way; and group 4, serving as positive controls, received daily only vanillin. After 10 days of treatment, mice of all groups were killed. Our results showed that vanillin significantly reduced the elevated hepatic levels of malondialdehyde, hydrogen peroxide, and advanced oxidation protein product and attenuated DNA fragmentation induced by maneb. In addition, vanillin modulated the alterations of antioxidant status: enzymatic (superoxide dismutase, catalase, and glutathione peroxidase) and nonenzymatic (reduced glutathione, nonprotein thiol, and vitamin C) antioxidants in the liver of maneb-treated mice. This natural compound was also able to ameliorate plasma biochemical parameters (aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transpeptidase, alkaline phosphatase, total bilirubin, and total protein). The protective effect of vanillin was further evident through the histopathological changes produced by maneb in the liver tissue. Thus, we concluded that vanillin might be beneficial against maneb-induced hepatic damage in mice.

Green tea consumption and risk of type 2 diabetes in Chinese adults: the Shanghai Women's Health Study and the Shanghai Men's Health Study

Background

Epidemiological evidence on the association between tea consumption and the risk of type 2 diabetes (T2D) is inconsistent. This study prospectively investigated whether green tea drinking affects the risk of T2D.

Methods

This study included participants from the Shanghai Women's Health Study (N = 67 058) and the Shanghai Men's Health Study (N  =  52 315) without diabetes at study enrolment. Details of tea consumption, including types and amounts, were collected at the baseline and follow-up survey. Incident T2D was identified through follow-up surveys. Plasma level of caffeine metabolite was measured in a nested case-control study involving 592 diabetes case-control pairs. Cox regression analysis, with tea drinking as a time-dependent variable and covariates adjusted for by a propensity score, was applied to estimate the hazard ratio (HR) and 95% confidence interval (CI) for T2D risk. Logistic regression analysis was applied to evaluate the association between caffeine metabolites and T2D risk.

Results

Current green tea drinkers had an increased risk of T2D compared with non-current drinkers [HR = 1.20 (95% CI = 1.14-1.27)], and a dose-response relationship was observed for duration of drinking tea and the amount of tea consumed [P for trend <0.001]. The increased risk associated with green tea drinking was observed in both women and men, across the entire period of follow-up, with HR (95% CI) of 1.08 (0.97-1.19) within 5 years of follow-up, 1.22 (1.12-1.32) during the period of 5-10 years of follow-up and 1.16 (1.03-1.30) after 10 years of follow-up. This association did not vary significantly by body mass index, waist-to-hip circumference ratio or smoking status. Plasma level of caffeine was also associated with increased diabetes risk (P  =  0.03), confirming the results based on self-reported tea drinking.

Conclusions

Green tea drinking was associated with an increased risk of T2D in Chinese adults. The mechanisms underlying the association need to be elucidated.

Elevated Levels of Organochlorine Pesticides in South Asian Immigrants Are Associated With an Increased Risk of Diabetes

OBJECTIVE

Rates of diabetes mellitus are higher in South Asians than in other populations and persist after migration. One unexplored cause may be higher exposure to persistent organic pollutants associated with diabetes in other populations. We compared organochlorine (OC) pesticide concentrations in South Asian immigrants and European whites to determine whether the disease was positively associated with OC pesticides in South Asians.

RESEARCH DESIGN AND METHODS

South Asians of Tamil or Telugu descent (n = 120) and European whites (n = 72) were recruited into the London Life Sciences Population Study cohort. Blood samples as well as biometric, clinical, and survey data were collected. Plasma levels of p,p'-dichlorodiphenyldichloroethylene (DDE), p,p'- dichlorodiphenyltrichloroethane, β-hexachlorohexane (HCH), and polychlorinated biphenyl-118 were analyzed by gas chromatography-mass spectrometry. South Asian cases and controls were categorized by binary exposure (above vs below the 50th percentile) to perform logistic regression.

RESULTS

Tamils had approximately threefold to ninefold higher levels of OC pesticides, and Telugus had ninefold to 30-fold higher levels compared with European whites. The odds of exposure to p,p'-DDE above the 50th percentile was significantly greater in South Asian diabetes cases than in controls (OR: 7.00; 95% CI: 2.22, 22.06). The odds of exposure to β-HCH above the 50th percentile was significantly greater in the Tamil cases than in controls (OR: 9.35; 95% CI: 2.43, 35.97).

CONCLUSIONS

South Asian immigrants have a higher body burden of OC pesticides than European whites. Diabetes mellitus is associated with higher p,p'-DDE and β-HCH concentrations in this population. Additional longitudinal studies of South Asian populations should be performed.

4,4'-Dichlorodiphenyltrichloroethane (DDT) and 4,4'-dichlorodiphenyldichloroethylene (DDE) inhibit myogenesis in C2C12 myoblasts

BACKGROUND

Most countries have banned the use of 4,4'-dichlorodiphenyltrichloroethane (DDT). However, owing to its extremely high lipophilic characteristics, DDT and its metabolite 4,4'-dichlorodiphenyldichloroethylene (DDE) are ubiquitous in the environment and in many types of food. The positive correlation between exposure to insecticides, including DDT and DDE, and weight gain, resulting in impaired energy metabolism in offspring following perinatal DDT and DDE exposure, was previously reported. Therefore the influence of DDT and DDE on myogenesis using C2C12 myoblasts was investigated in this study.

RESULTS

DDT and DDE decreased myotube formation dose- and time-dependently. Among myogenic regulatory factors, DDT and DDE mainly decreased MyoD1 and Myf5 expression. DDT and DDE treatment also altered Myostatin expression, phosphorylation of protein kinase B, p70 ribosomal protein S6 kinase, forkhead box O protein 3 and mammalian target of rapamycin, resulting in attenuation of myotube formation.

CONCLUSION

These results may have significant implications for understanding the effects of developmental exposure of DDT and DDE on myogenesis and development of obesity and type 2 diabetes later in life. © 2017 Society of Chemical Industry.

Permethrin decreased insulin-stimulated AKT phosphorylation dependent on extracellular signal-regulated kinase-1 (ERK), but not AMP-activated protein kinase α (AMPKα), in C2C12 myotubes

Previously 10 μM permethrin (38.7% cis and 59.4% trans isomers), a pyrethroid insecticide widely used in agriculture and household products for pest control, was reported to reduce insulin-stimulated glucose uptake and phosphorylation of protein kinase B (p-AKT) in C2C12 mouse myotubes. The underlying mechanisms on how permethrin decreases insulin-stimulated AKT phosphorylation, however, are unknown. Thus, the goal of this study was to determine the possible mechanism(s) through which permethrin reduced insulin-stimulated AKT phosphorylation in C2C12 myotubes. Permethrin treatment, at 10 μM, decreased insulin-stimulated membrane glucose transporter type 4 (GLUT4) and AKT phosphorylation, and increased insulin receptor substrate 1 (IRS1) Ser307 phosphorylation in the presence of insulin. The inactivation of AKT by permethrin was independent of AMPKα. ERK inactivation by U0126, however, restored insulin-stimulated AKT phosphorylation, which was decreased by permethrin treatment. These results suggest that permethrin decreased insulin-stimulated AKT phosphorylation via ERK activation, but not by AMPKα inactivation.

Imidacloprid Promotes High Fat Diet-Induced Adiposity in Female C57BL/6J Mice and Enhances Adipogenesis in 3T3-L1 Adipocytes via the AMPKα-Mediated Pathway

Imidacloprid, a neonicotinoid insecticide, was previously reported to enhance adipogenesis and resulted in insulin resistance in cell culture models. It was also reported to promote high fat diet-induced obesity and insulin resistance in male C57BL/6J mice. Thus, the goal of the present study was to determine the effects of imidacloprid and dietary fat interaction on the development of adiposity and insulin resistance in female C57BL/6J mice. Mice were fed with a low (4% w/w) or high fat (20% w/w) diet containing imidacloprid (0.06, 0.6, or 6 mg/kg bw/day) for 12 weeks. Mice fed with imidacloprid (0.6 mg/kg bw/day) significantly enhanced high fat diet-induced weight gain and adiposity. Treatment with imidacloprid significantly increased serum insulin levels with high fat diet without effects on other markers of glucose homeostasis. AMPKα activation was significantly inhibited by 0.6 and 6 mg imidacloprid/kg bw/day in white adipose tissue. Moreover, AMPKα activation with 5-aminoimidazole-4-carboxamide ribonucleotide abolished the effects of imidacloprid (10 μM) on enhanced adipogenesis in 3T3-L1 adipocytes. N-Acetyl cysteine also partially reversed the effects of imidacloprid on reduced phosphorylation of protein kinase B (AKT) in C2C12 myotubes. These results indicate that imidacloprid may potentiate high fat diet-induced adiposity in female C57BL/6J mice and enhance adipogenesis in 3T3-L1 adipocytes via the AMPKα-mediated pathway. Imidacloprid might also influence glucose homeostasis partially by inducing cellular oxidative stress in C2C12 myotubes.

Potential contribution of insecticide exposure and development of obesity and type 2 diabetes

The introduction of insecticides has greatly improved agricultural productivity and human nutrition; however, the wide use of insecticides has also sparked growing concern over their health impacts. Increased rate of cancers, neurodegenerative disorders, reproductive dysfunction, birth defects, respiratory diseases, cardiovascular diseases and aging have been linked with insecticide exposure. Meanwhile, a growing body of evidence is suggesting that exposure to insecticides can also potentiate the risk of obesity and type 2 diabetes. This review summarizes the relationship between insecticide exposure and development of obesity and type 2 diabetes using epidemiological and rodent animal studies, including potential mechanisms. The evidence as a whole suggests that exposure to insecticides is linked to increased risk of obesity and type 2 diabetes.