Prospective associations between persistent organic pollutants and metabolic syndrome: a nested case-control study

Association between polychlorinated biphenyls and hypertension risk: a systematic review and meta-analysis

Background and Aim

Hypertension (HTN) is a widespread global health challenge, and its increasing prevalence is attributed to individual and environmental risk factors. Persistent organic pollutants (POPs), especially polychlorinated biphenyls (PCBs), contribute to cardiovascular risk by accumulating in fatty tissues, which leads to oxidative stress and vascular inflammation. This review and meta-analysis aimed to investigate the association between PCB exposure and hypertension.

Methods

Adhering to the PRISMA 2020 guidelines, data sources such as PubMed, Scopus, Web of Science, and Google Scholar were systematically searched up to July 2024 to find observational studies on the link between PCBs and hypertension risk. Studies were reviewed and chosen according to established inclusion and exclusion criteria, focusing on observational studies examining PCB exposure and hypertension risk. Independent reviewers conducted data extraction, and the quality of studies was evaluated using the JBI critical appraisal tool. A meta-analysis with a random-effects model was conducted to determine combined odds ratios (ORs) for hypertension linked to total PCB exposure and specific PCB types.

Results

Of the 494 records identified, 21 studies met the inclusion criteria, comprising 5 cohort studies, 15 cross-sectional studies, and one case-control study, totaling 51,514 participants. Exposure to total PCBs correlated with an elevated risk of hypertension (OR = 1.78, 95% CI: 1.30-2.44). Dioxin-like PCBs were also associated with a heightened risk (OR = 1.54, 95% CI: 1.24-1.90), while non-dioxin-like PCBs were not significantly linked (OR = 1.16, 95% CI: 0.81-1.66). Among individual congeners, PCB-74, PCB-118, PCB-105, and PCB-153 were significantly related to higher hypertension risk.

Conclusion

These findings indicate a positive correlation between PCB exposure and hypertension, particularly with dioxin-like PCBs and certain PCB congeners. Additional research is necessary to clarify the mechanisms involved and to promote measures for reducing PCB exposure, particularly in high-risk populations.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024595223, PROSPERO (CRD42024595223).

Exposure to PCB52 (2,2',5,5'-tetrachlorobiphenyl) blunts induction of the gene for uncoupling protein 1 (UCP1) in white adipose

Polychlorinated biphenyls (PCBs) are linked to cancer, learning disabilities, liver and cardiovascular disease, and diabetes. Older schools often contain high levels of PCBs, and inhalation is a major source of exposure. Technical PCB mixtures, called Aroclors, and individual dioxin-like PCBs impair adipocyte function, which can lead to type II diabetes. To determine how PCB52, a non-dioxin like PCB congener found in school air, affects adipose, adolescent male and female rats were exposed to PCB52 by nose-only inhibition for 4 h per day for 28 consecutive days. Transcriptomic analysis of white adipose revealed sex-specific differences in gene expression between PCB52- and sham-exposed males and females. Exposed females showed mitochondrial gene changes, including downregulation of the thermogenic uncoupling gene, Ucp1. Human preadipocytes/adipocytes exposed to PCB52 or its main metabolite, 4-OH-PCB52, also showed reduced norepinephrine-induced UCP1 expression. These findings suggest that PCB52 inhalation disrupts thermogenesis in adipose tissue, potentially contributing to metabolic syndrome.

Upregulation of fatty acid synthesis genes in the livers of adolescent female rats caused by inhalation exposure to PCB52 (2,2',5,5'-Tetrachlorobiphenyl)

Elevated airborne PCB levels in older schools are concerning due to their health impacts, including cancer, metabolic dysfunction-associated steatotic liver disease (MASLD), cardiovascular issues, neurodevelopmental diseases, and diabetes. During a four-week inhalation exposure to PCB52, an air pollutant commonly found in school environments, adolescent rats exhibited notable presence of PCB52 and its hydroxylated forms in their livers, alongside changes in gene expression. Female rats exhibited more pronounced changes in gene expression compared to males, particularly in fatty acid synthesis genes regulated by the transcription factor SREBP1. In vitro studies with human liver cells showed that the hydroxylated metabolite of PCB52, 4-OH-PCB52, but not the parent compound, upregulated genes involved in fatty acid biosynthesis similar to in vivo exposure. These findings highlight the sex-specific effects of PCB52 exposure on livers, particularly in females, suggesting a potential pathway for increased MASLD susceptibility.

Weight loss treatment for COVID-19 in patients with NCDs: a pilot prospective clinical trial

COVID-19 comorbid with noncommunicable chronic diseases (NCDs) complicates the diagnosis, treatment, and prognosis, and increases the mortality rate. The aim is to evaluate the effects of a restricted diet on clinical/laboratory inflammation and metabolic profile, reactive oxygen species (ROS), and body composition in patients with COVID-19 comorbid with NCDs. We conducted a 6-week open, pilot prospective controlled clinical trial. The study included 70 adult patients with COVID-19 comorbid with type 2 diabetes (T2D), hypertension, or nonalcoholic steatohepatitis (NASH).

INTERVENTIONS

a restricted diet including calorie restriction, hot water drinking, walking, and sexual self-restraint.

PRIMARY ENDPOINTS

COVID-19 diagnosis by detecting SARS-CoV-2 genome by RT-PCR; weight loss in Main group; body temperature; C-reactive protein. Secondary endpoints: the number of white blood cells; erythrocyte sedimentation rate; adverse effects during treatment; fasting blood glucose, glycosylated hemoglobin A1c (HbA1c), systolic/diastolic blood pressure (BP); blood lipids; ALT/AST, chest CT-scan. In Main group, patients with overweight lost weight from baseline (- 12.4%; P < 0.0001); 2.9% in Main group and 7.2% in Controls were positive for COVID-19 (RR: 0.41, CI: 0.04-4.31; P = 0.22) on the 14th day of treatment. Body temperature and C-reactive protein decreased significantly in Main group compared to Controls on day 14th of treatment (P < 0.025). Systolic/diastolic BP normalized (P < 0.025), glucose/lipids metabolism (P < 0.025); ALT/AST normalized (P < 0.025), platelets increased from baseline (P < 0.025), chest CT (P < 0.025) in Main group at 14 day of treatment. The previous antidiabetic, antihypertensive, anti-inflammatory, hepatoprotective, and other symptomatic medications were adequately decreased to completely stop during the weight loss treatment. Thus, the fast weight loss treatment may be beneficial for the COVID-19 patients with comorbid T2D, hypertension, and NASH over traditional medical treatment because, it improved clinical and laboratory/instrumental data on inflammation; glucose/lipid metabolism, systolic/diastolic BPs, and NASH biochemical outcomes, reactive oxygen species; and allowed patients to stop taking medications.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05635539 (02/12/2022): https://clinicaltrials.gov/ct2/show/NCT05635539?term=NCT05635539&draw=2&rank=1 .

An exposome atlas of serum reveals the risk of chronic diseases in the Chinese population

Although adverse environmental exposures are considered a major cause of chronic diseases, current studies provide limited information on real-world chemical exposures and related risks. For this study, we collected serum samples from 5696 healthy people and patients, including those with 12 chronic diseases, in China and completed serum biomonitoring including 267 chemicals via gas and liquid chromatography-tandem mass spectrometry. Seventy-four highly frequently detected exposures were used for exposure characterization and risk analysis. The results show that region is the most critical factor influencing human exposure levels, followed by age. Organochlorine pesticides and perfluoroalkyl substances are associated with multiple chronic diseases, and some of them exceed safe ranges. Multi-exposure models reveal significant risk effects of exposure on hyperlipidemia, metabolic syndrome and hyperuricemia. Overall, this study provides a comprehensive human serum exposome atlas and disease risk information, which can guide subsequent in-depth cause-and-effect studies between environmental exposures and human health.

Exposure to organochlorine pesticides and polychlorinated biphenyls, adherence to an ideal cardiovascular health, and arterial stiffness among Chinese adults

This study aimed to assess the relationships between exposure to individual organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and their mixture and arterial stiffness and explore whether adherence to an ideal cardiovascular health (CVH) could mitigate these associations. The cross-sectional study enrolled 1437 Chinese adults between March and May 2019 in Wuhan, China. OCPs and PCBs concentrations were measured using solid phase extraction coupled with gas chromatography-tandem mass spectrometry. Arterial stiffness was evaluated by brachial-ankle pulse wave velocity (baPWV). CVH was determined by three behavioral and four biological metrics and categorized as ideal, intermediate, and poor CVH. We applied generalized linear model and weighted quantile sum (WQS) regression to evaluate the associations of exposure to individual OCPs or PCBs and their mixture with baPWV, respectively. We found that participants with detectable levels of heptachlor epoxide, PCB-153, and PCB-180 had higher baPWV (β: 34.25, 95% CI 14.28-54.22; β: 27.64, 95% CI 7.90-47.38; and β: 30.51, 95% CI 10.68-50.35) than those with undetectable levels. In WQS regression, the mixture of OCPs and PCBs was related to a higher baPWV (β: 24.93, 95% CI 2.70-47.15). Compared with participants with ideal CVH and undetectable OCPs or PCBs levels, those with poor CVH and detectable OCPs or PCBs levels had the highest increase in baPWV (heptachlor epoxide: β: 147.94, 95% CI 112.52-183.55; PCB-153: β: 150.22, 95% CI 115.40-185.04; PCB-180: β: 147.02, 95% CI 111.66-182.38). Our findings suggested that individual OCPs, PCBs, and their mixture exposure were positively associated with arterial stiffness, and adherence to an ideal CVH may mitigate the adverse effect.

Polychlorinated biphenyls and risk of metabolic syndrome and comparison with the risk of diabetes: A systematic review and meta-analysis

With the increasing incidence of metabolic syndrome (MetS) worldwide and no consistent results on PCBs and MetS. A meta-analysis to explore their relationship was conducted. Given the high correlation and overlap of MetS with diabetes, analysis of diabetes risk, was used as a supplement to compare with MetS. Seven studies included MetS, 15 studies for diabetes, and one study included both outcomes. It was found that PCBs may not be a risk factor for MetS, but their high heterogeneity indicates that they are under-represented. In addition, our results showed that total PCBs might be a protective factor against diabetes. In the whole blood subgroup, which can reflect the accumulation of more than one body load, heterogeneity was reduced, and its OR value suggested that PCBs increased the risk of MetS in the whole blood biomaterial. DL-PCBs were positively associated with MetS and diabetes, while NDL-PCBs were negatively associated with diabetes. In the subgroup analysis of PCBs homologs, DL-PCB-126 and DL-PCB-118 were risk factors for MetS and diabetes, respectively. In addition, PCB-153 and 180 showed a dose-response relationship between them and diabetes mellitus, respectively. The results of total analysis of MetS and diabetes mellitus and subgroup analysis of PCBs were mixed, and this reason might be attributed to the different mechanisms of action and effect sizes of different PCBs, so based on subgroup results and in vivo and in vitro experiments, we considered PCBs to be a risk factor for MetS and diabetes. Due to various reasons, there are still many shortcomings in the evaluation of PCBs impact on human health, and more high-quality research are needed to further explore the role of PCBs of different species and congeners in MetS and diabetes.

Individual and mixtures of polychlorinated biphenyls and organochlorine pesticides exposure in relation to metabolic syndrome among Chinese adults

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) are commonly detected in humans due to their persistence and bioaccumulation, and are suspected risk factors for metabolic syndrome (MetS). However, most studies have focused on individual rather than combined exposure. We explored the associations between individual and combined PCBs/OCPs exposure and MetS to better assess the health effects of PCBs and OCPs. This cross-sectional study included 1996 adults from Wuhan, China. A total of 338 participants fulfilled criteria for MetS. Eight PCBs and OCPs were detected in >50 % of the samples. Most of the hexachlorocyclohexanes (HCHs) in the serum were derived from the recent environmental input of lindane, while the high levels of dichlorodiphenyltrichloroethane (DDTs) were mainly due to historical use. Multivariate linear regression analyses revealed that β-HCH, p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), PCB-52, PCB-153, and PCB-180 were positively correlated with increased odds of MetS. The profiles of the PCBs and OCPs associated with the different components of MetS were distinct. Furthermore, quantile-based g computation (qgcomp) analyses showed that PCB and OCP mixtures were positively associated with the risk of MetS, and p,p'-DDE was the largest contributor to our model. These findings suggest that PCB and OCP concentrations, both individually and as mixtures, are associated with MetS risk. Prospective studies are needed to confirm these results.

Cross-sectional associations of persistent organic pollutants measured in adipose tissue and metabolic syndrome in clinically diagnosed middle-aged adults

INTRODUCTION

Although often overlooked in clinical settings, accumulation of persistent organic pollutants (POPs) in visceral adipose tissue (VAT) is thought to be a relevant risk factor for metabolic syndrome (MetS).

METHODS

One hundred and seventeen patients undergoing non-oncological surgery were randomly recruited and classified as MetS + if presented 3 out of the 5 MetS components: waist circumference (WC), systolic and diastolic blood pressure (SBP and DBP, respectively), serum glucose, insulin, triglycerides (TG) and high-density lipoprotein (HDL) cholesterol levels, according International Diabetes Federation (IDF) criteria. Seventeen organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were measured in adipose tissue samples. Linear, logistic and weighted quantile sum (WQS) regression models, adjusted for age and sex, were performed.

RESULTS

One third of the participants were males (36.8%) with a median age of 44 years, showing clinical evidences of MetS (35.0%). Adjusted linear regression models showed that WC correlated positively with all OCP concentrations. Higher fasting serum glucose levels were related to higher HCB and γ-HCH concentrations. The remaining OCPs and PCBs were not associated with this MetS component. HCB was inversely associated with HDL cholesterol levels, while PCB-180 was positively associated. HCB and γ-HCH concentrations were also positively correlated with DBP and SBP levels. PCB-138 was also positively associated with SBP. Adjusted logistic models revealed that exposure to HCB and γ-HCH were associated with increased odds of MetS [ORs (95%CI) 1.53 (1.22-1.92) and 1.39 (1.10-1.76) respectively; p < 0.01]. No associations were observed for the remaining POPs. WQS models showed a positive and significant mixture effect of POPs on the odds of MetS (exp [beta] = 2.34; p < 0.001), with γ-HCH (52.9%), o,p'-DDT (26.9%) and HCB (19.7%) driving the association.

CONCLUSIONS

Our findings support that POPs accumulated in VAT, specifically HCB and (gamma)-HCH, are associated with both isolated components and clinically diagnosed SMT.

Toxicity Impacts on Human Adipose Mesenchymal Stem/Stromal Cells Acutely Exposed to Aroclor and Non-Aroclor Mixtures of Polychlorinated Biphenyl

Polychlorinated biphenyl (PCB) accumulates in adipose where it may impact the growth and function of cells within the tissue. This is particularly concerning during adolescence when adipocytes expand rapidly. Herein, we sought to understand how exposure to PCB mixtures found in U.S. schools affects human adipose mesenchymal stem/stromal cell (MSC) health and function. We investigated how exposure to Aroclor 1016 and Aroclor 1254, as well as a newly characterized non-Aroclor mixture that resembles the PCB profile found in cabinets, Cabinet Mixture, affects adipose MSC growth, viability, and function in vitro. We found that exposure to all three mixtures resulted in two distinct types of toxicity. At PCB concentrations >20 μM, the majority of MSCs die, while at 1-10 μM, MSCs remained viable but display numerous alterations to their phenotype. At these sublethal concentrations, the MSC rate of expansion slowed and morphology changed. Further assessment revealed that PCB-exposed MSCs had impaired adipogenesis and a modest decrease in immunosuppressive capabilities. Thus, exposure to PCB mixtures found in schools negatively impacts the health and function of adipose MSCs. This work has implications for human health due to MSCs' role in supporting the growth and maintenance of adipose tissue.

Metabolic syndrome and pesticides: A systematic review and meta-analysis

The relation between pesticides exposure and metabolic syndrome (MetS) has not been clearly identified. Performing a systematic review and meta-analysis, PubMed, Cochrane Library, Embase, and ScienceDirect were searched for studies reporting the risk of MetS following pesticides exposure and their contaminants. We included 12 studies for a total of 6789 participants, in which 1981 (29.1%) had a MetS. Overall exposure to pesticides and their contaminants increased the risk of MetS by 30% (95CI 22%-37%). Overall organochlorine increased the risk of MetS by 23% (14-32%), as well as for most types of organochlorines: hexachlorocyclohexane increased the risk by 53% (28-78%), hexachlorobenzene by 40% (0.01-80%), dichlorodiphenyldichloroethylene by 22% (9-34%), dichlorodiphenyltrichloroethane by 28% (5-50%), oxychlordane by 24% (1-47%), and transnonchlor by 35% (19-52%). Sensitivity analyses confirmed that overall exposure to pesticides and their contaminants increased the risk by 46% (35-56%) using crude data or by 19% (10-29%) using fully-adjusted model. The risk for overall pesticides and types of pesticides was also significant with crude data but only for hexachlorocyclohexane (36% risk increase, 17-55%) and transnonchlor (25% risk increase, 3-48%) with fully-adjusted models. Metaregressions demonstrated that hexachlorocyclohexane increased the risk of MetS in comparison to most other pesticides. The risk increased for more recent periods (Coefficient = 0.28, 95CI 0.20 to 0.37, by year). We demonstrated an inverse relationship with body mass index and male gender. In conclusion, pesticides exposure is a major risk factor for MetS. Besides organochlorine exposure, data are lacking for other types of pesticides. The risk increased with time, reflecting a probable increase of the use of pesticides worldwide. The inverse relationship with body mass index may signify a stockage of pesticides and contaminants in fat tissue.

Transcriptome sequencing of 3,3',4,4',5-Pentachlorobiphenyl (PCB126)-treated human preadipocytes demonstrates progressive changes in pathways associated with inflammation and diabetes

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that accumulate in adipose tissue and have been associated with cardiometabolic disease. We have previously demonstrated that exposure of human preadipocytes to the dioxin-like PCB126 disrupts adipogenesis via the aryl hydrocarbon receptor (AhR). To further understand how PCB126 disrupts adipose tissue cells, we performed RNAseq analysis of PCB126-treated human preadipocytes over a 3-day time course. The most significant predicted upstream regulator affected by PCB126 exposure at the early time point of 9 h was the AhR. Progressive changes occurred in the number and magnitude of transcript levels of genes associated with inflammation, most closely fitting the pathways of cytokine-cytokine-receptor signaling and the AGE-RAGE diabetic complications pathway. Transcript levels of genes involved in the IL-17A, IL-1β, MAP kinase, and NF-κB signaling pathways were increasingly dysregulated by PCB126 over time. Our results illustrate the progressive time-dependent nature of transcriptional changes caused by toxicants such as PCB126, point to important pathways affected by PCB126 exposure, and provide a rich dataset for further studies to address how PCB126 and other AhR agonists disrupt preadipocyte function. These findings have implications for understanding how dioxin-like PCBs and other dioxin-like compounds are involved in the development of obesity and diabetes.

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.

Persistent Organic Pollutants in Human Milk: Exposure Levels and Determinants among Lactating Mothers in Lebanon

ABSTRACT

Exposure of newborns to persistent organic pollutants (POPs) is a public health concern. The objective of this study was to assess the prevalence of POPs in human milk collected from lactating mothers in Lebanon and to investigate the sociodemographic, nutritional, and other lifestyle determinants. Fifty-four breast milk samples were collected as per World Health Organization guidelines. A survey was used to assess the anthropometric and demographic characteristics of participants. Dietary habits were evaluated based on a semiquantitative food frequency questionnaire. Organochlorine pesticides and polychlorinated biphenyls were measured in milk samples with liquid-liquid extraction and gas chromatography. Among the screened POPs, dichlorodiphenyldichloroethylene (DDE) was the only POP detected in breast milk samples and was found in only 17.9% of the samples, with a mean (SD) of 11.6 (5.0) μg/L and a range of 5.7 to 21.4 μg/L. Prepregnancy body mass index and age were positively associated with DDE contamination in breast milk. Women who consumed cereals at least two times per week had detectable DDE contamination in their breast milk. Consumption of potatoes and beans at least once per week was also associated with DDE contamination. Our study is the first to assess the presence of POPs in breast milk in Lebanon. The benefits of breastfeeding compensate for the low prevalence of DDE in the breast milk. Our findings highlight the high need to implement monitoring policies, good agricultural practices, and education programs for breastfeeding mothers.

HIGHLIGHTS

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.

Incidence of Arterial Hypertension in People With Periodontitis and Characterization of the Oral and Subgingival Microbiome: A Study Protocol

Cardiovascular diseases are the leading cause of morbidity and mortality worldwide. High blood pressure in particular, continues to increase throughout the global population at an increasingly fast pace. The relationship between arterial hypertension and periodontitis has been recently discussed in the context of its origins and implications. Particularly relevant is the role of the periodontal microbiome linked to persistent local and systemic inflammation, along with other risk factors and social determinants of health. The present protocol will investigate/assess the association between periodontal disease and its microbiome on the onset of hypertension, within a cohort from Mexico City. One thousand two hundred twelve participants will be studied during a 60-month period. Studies will include analysis of periodontal conditions, sampling and sequencing of the salivary and subgingival microbiome, interviews on nutritional and lifestyle habits, social determinants of health, blood pressure and anthropometric measurements. Statistical associations and several classic epidemiology and machine learning approaches will be performed to analyze the data. Implications for the generation of public policy—by early public health interventions or epidemiological surveillance approaches—and for the population empowerment—via the establishment of primary prevention recommendations, highlighting the relationship between oral and cardiovascular health—will be considered. This latter set of interventions will be supported by a carefully planned science communication and health promotion strategy. This study has been registered and approved by the Research and Ethics Committee of the School of Dentistry, Universidad Nacional Autónoma de México (CIE/0308/05/2019) and the National Institute of Genomic Medicine (CEI/2020/12). The umbrella cohort was approved by the Institutional Bioethics Committee of the National Institute of Cardiology-Ignacio Chavez (INC-ICh) under code 13-802.

Markers of acute toxicity of DDT exposure in pancreatic beta-cells determined by a proteomic approach

Many compounds have the potential to harm pancreatic beta-cells; organochlorine pollutants belong to those compounds. In this work, we aimed to find markers of acute toxicity of p,p'-DDT exposure among proteins expressed in NES2Y human pancreatic beta-cells employing 2-D electrophoresis. We exposed NES2Y cells to a high concentration (150 μM, LC96 after 72 hours) of p,p'-DDT for 24 and 30 hours and determined proteins with changed expression using 2-D electrophoresis. We have found 22 proteins that changed their expression. They included proteins involved in ER stress (GRP78, and endoplasmin), mitochondrial proteins (GRP75, ECHM, IDH3A, NDUS1, and NDUS3), proteins involved in the maintenance of the cell morphology (EFHD2, TCPA, NDRG1, and ezrin), and some other proteins (HNRPF, HNRH1, K2C8, vimentin, PBDC1, EF2, PCNA, biliverdin reductase, G3BP1, FRIL, and HSP27). The proteins we have identified may serve as indicators of p,p'-DDT toxicity in beta-cells in future studies, including long-term exposure to environmentally relevant concentrations.

Association between exposure to polychlorinated biphenyls and risk of hypertension: A systematic review and meta-analysis

Experimental and epidemiological studies have suggested an association between exposure to polychlorinated biphenyls (PCBs), ubiquitous environmental toxic compounds, and the risk of hypertension. We conducted a systematic review and meta-analysis of epidemiological studies of the association between PCB exposure and the risk of hypertension. Studies were identified by searching PubMed, Embase and Web of Science and by reviewing reference lists. Study-specific risk estimates comparing the highest versus lowest quantile of PCB distribution were combined using random-effects models. We identified 10 cross-sectional studies, 6 cohort studies, and 1 nested case-control study. A pooled excess risk of hypertension was found for total PCBs (OR 1.70, 95% CI 1.28-2.26), dioxin-like (DL)-PCBs (OR 1.46, 1.19-1.79), but not for non-dioxin like (NDL)-PCBs (OR 1.19, 0.81-1.73) comparing the highest with the lowest quartile of the distribution. According to a dose-response meta-analysis, a linear dose-effect relationship was found for total PCBs [OR 2.23 (95% CI: 1.59-3.14) for 1000 ng PCB/g lipid increase]. This positive association remained when stratifying the analyses by study design (cohort vs cross-sectional studies) and population (general population vs high exposed workers/residents). Among single PCB congeners, DL-PCB 105 and 118, and non-DL-PCB138 and 153 were related to hypertension. In conclusion, this meta-analysis suggests that exposure to PCBs, particularly to DL-PCBs, may be a risk factor for hypertension, independently of other risk factors.

Potential therapeutic applications of the gut microbiome in obesity: from brain function to body detoxification

The prevalence of obesity is rising every year and associated comorbidities such as cardiovascular diseases are among the leading causes of death worldwide. The gut microbiota has recently emerged as a potential target for therapeutic applications to prevent and treat those comorbidities. In this review, we focus on three conditions related to obesity in which the use of gut microbiota modulators could have benefits; mood disorders, eating behaviors, and body detoxification of persistent organic pollutants (POPs). On one hand, modulation of gut-derived signals to the brain in a context of obesity is involved in the development of neuroinflammation and can subsequently alter behaviors. An altered gut microbiome could change these signals and alleviate their consequences. On the other hand, obesity is associated with an increased accumulation of lipophilic contaminants, such as POPs. Targeting the microbiota could help body detoxication by reducing bioavailability, enhancing degradation by bioremediation or their excretion through the enterohepatic circulation. Thus, a supplementation of prebiotics, probiotics, or synbiotics could represent a complementary strategy to current ones, such as medication and lifestyle modifications, to decrease depression, alter eating behaviors, and lower body burden of pollutants considering the actual obesity epidemic our society is facing.

Association of plasma levels of lipid and polychlorinated biphenyls in Iranian adult

Background

Exposure to Polychlorinated biphenyls (PCBs) continues over the world through seafood consumption and indoor exposure to building materials containing PCB. This study aimed to assess the relationship between plasma level of PCB congeners and lipid profile and Body Mass Index (BMI) as well.

Methods

The study population consisted of 181 Iranian adults. Data on BMI, plasma concentration of PCB congeners and serum level of lipid profile including Triglyceride, low-density lipoproteins and high-density lipoproteins, recruited from database of a project entitled “Occupational and environmental exposure to PCBs in Iran”. Multiple linear regression analysis of associations between different quartiles of PCB congeners and various lipid fractions and BMI have been conducted.

Results

A linear increase in average serum Triglyceride and low-density lipoproteins (LDL) levels of participants in first, second, third and fourth quartiles of some PCB congeners was obtained. Following adjustment for age, gender, diet and other variables, only the association between different quartiles of PCB 138, PCB 153, PCB 118 and PCB sum and TG remained statistically significant.

Conclusion

The study showed a significant positive relation between plasma PCBs concentrations and serum level of TG in the study population with normal PCBs levels.

A screening-level approach to quantifying risk from glacial release of organochlorine pollutants in the Alaskan Arctic

Widespread distribution of atmospherically mobilized organochlorine pollutants (OCPs) has been documented throughout the Arctic. A fraction of these OCPs have become entrained in glacial ice, and during melting, they can be released into downstream reservoirs. Though this remobilization is known, an assessment of risk from glacial meltwater to collocated human communities in the Arctic, including Alaska, had not been accomplished. Here, we use a screening-level risk assessment model for glacial watersheds, based on US Environmental Protection Agency (EPA) methodology, which we apply to the glaciated Jarvis Creek watershed of interior Alaska. Model results indicate that even with low levels of OCPs in glacial meltwater, high fish consumption by subsistence communities in the area increases the risk of cancer and hazard impacts above acceptable limits. Though this model is specific to one watershed, our results imply that further investigation of an increasing OCP signal in glacial meltwater and fish throughout the North American Arctic is warranted.

Associations between persistent organic pollutants and metabolic syndrome in morbidly obese individuals

BACKGROUND AND AIMS

Persons with "metabolically healthy" obesity may develop cardiometabolic complications at a lower rate than equally obese persons with evident metabolic syndrome. Even morbidly obese individuals vary in risk profile. Persistent organic pollutants (POPs) are widespread environmental chemicals that impair metabolic homeostasis. We explored whether prevalence of metabolic syndrome in morbidly obese individuals is associated with serum concentrations of POPs.

METHODS AND RESULTS

A cross-sectional study among 161 men and 270 women with BMI >35 kg/m² and comorbidity, or >40 kg/m². Circulating concentrations of 15 POPs were stratified by number of metabolic syndrome components. In multiple logistic regression analysis odds ratios between top quartile POPs and metabolic risk factors versus POPs below the top quartile were calculated adjusting for age, gender, body mass index, smoking status, alcohol consumption and cholesterol concentrations. Age-adjusted concentrations of trans-nonachlor and dioxin-like and non-dioxin-like polychlorinated biphenyls (PCBs) increased with number of metabolic syndrome components in both genders (p < 0.001), while the organochlorine pesticides HCB, β-HCH and p,p'DDE increased only in women (p < 0.008). Organochlorine pesticides in the top quartile were associated with metabolic syndrome as were dioxin-like and non-dioxin-like PCBs (OR 2.3 [95% CI 1.3-4.0]; OR 2.5 [95% CI 1.3-4.8] and 2.0 [95% CI 1.1-3.8], respectively). Organochlorine pesticides were associated with HDL cholesterol and glucose (OR = 2.0 [95% CI = 1.1-3.4]; 2.4 [95% CI = 1.4-4.0], respectively). Dioxin-like PCBs were associated with diastolic blood pressure, glucose and homeostatic model assessment-insulin resistance index (OR = 2.0 [95% CI = 1.1-3.6], 2.1 [95% CI = 1.2-3.6] and 2.1 [95% CI = 1.0-4.3], respectively).

CONCLUSION

In subjects with morbid obesity, metabolic syndrome was related to circulating levels of organochlorine pesticides and PCBs suggesting that these compounds aggravate clinically relevant complications of obesity.

Persistent Organochlorine Pollutants in Plasma, Blood Pressure, and Hypertension in a Longitudinal Study

Persistent organochlorine pollutants (POPs) have shown to be involved in the atherosclerotic process and to cause endothelial cell dysfunction. To assess longitudinally whether plasma concentrations of different POPs were associated with blood pressure and risk of hypertension in middle-aged women and men. Study subjects were 850 participants in the VIP (Västerbotten Intervention Programme) with 2 blood samples and blood pressure measurements, 10 years apart, during 1990 to 2003 (baseline) and during 2000 to 2013 (follow-up). Dioxin-like and nondioxin-like polychlorinated biphenyls (DL-PCBs, NDL-PCBs) and p,p'-dichlorodiphenyldichloroethylene (DDE) were measured. Associations were assessed using generalized estimating equations. At baseline sampling 49% and at follow-up 64% had hypertension. DL-PCBs and DDE, but not NDL-PCBs or hexachlorobenzene, were associated with hypertension. Only the association for DL-PCBs remained statistically significant after lipid-standardization and adjustment for body mass index and total serum lipids. The multivariable-adjusted odds ratio of hypertension based on repeated measurements were 1.52 (95% confidence interval, 1.08-2.13) for DL-PCBs (third versus first tertile of lipid-standardized POPs). In stratified adjusted analyses, odds ratio for those born after 1950 increased to 3.99 (95% confidence interval, 2.15-7.43), whereas no association was observed among those born earlier. Based on repeated measurements, the accumulated exposure to DL-PCBs and DDE, although less clear for the latter, may disrupt the normal blood pressure levels and increase the odds of hypertension. Moreover, individuals experiencing early-life POP exposure may be at elevated risk of vascular POP effects.

A delayed proinflammatory response of human preadipocytes to PCB126 is dependent on the aryl hydrocarbon receptor

Inflammation in adipose tissue is recognized as a causative factor in the development of type II diabetes. Adipocyte hypertrophy as well as bacterial and environmental factors have been implicated in causing inflammation in mature adipocytes. Exposure to persistent organic pollutants such as polychlorinated biphenyls (PCBs) has been associated with the development of type II diabetes. We show here that PCB126, a dioxin-like PCB, activates a robust proinflammatory state in fat cell precursors (preadipocytes). The response was found to be dependent on aryl hydrocarbon receptor (AhR) activation, although induction of the response was delayed compared to upregulation of CYP1A1, a classic AhR-responsive gene. Treatment of preadipocytes with a nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) inhibitor partially attenuated the PCB126-induced inflammatory response and partly, but not completely, ameliorated disruption of adipogenesis caused by PCB126. Our results indicate a role for PCB126 in mediating an inflammatory response through AhR in preadipocytes that interferes with adipogenesis.

Blood Concentrations of Persistent Organic Pollutants and Unhealthy Metabolic Phenotypes in Normal-Weight, Overweight, and Obese Individuals

Factors underlying metabolic phenotypes, such as the metabolically healthy but obese phenotype, remain unclear. Differences in metabolic phenotypes-particularly, among individuals with a similar body mass index-could be related to concentrations of persistent organic pollutants (POPs). To our knowledge, no studies have analyzed POPs and metabolic phenotypes in normal-weight persons. We investigated the relationships between serum concentrations of POPs and metabolic phenotypes in 860 normal-weight, overweight, and obese participants in the 2002 Catalan Health Interview Survey (Spain). POP concentrations were significantly higher in metabolically unhealthy than in metabolically healthy individuals. In models adjusting for body mass index and other confounders, hexachlorobenzene, β-hexachlorocyclohexane, and polychlorinated biphenyls were associated with the unhealthy metabolic phenotype and metabolic syndrome. Among normal-weight individuals, the adjusted prevalence ratio of having an unhealthy phenotype for the upper category of the sum of orders of the 6 mentioned POPs (all individually associated with metabolic phenotypes) was 4.1 (95% confidence interval: 1.7, 10.0). Among overweight and obese individuals, the corresponding prevalence ratio for the sum of polychlorinated biphenyls was 1.4 (95% confidence interval: 1.0, 1.8). Our results supported the hypothesis that POP concentrations are associated with unhealthy metabolic phenotypes, not only in obese and overweight individuals but also (and probably more strongly) in normal-weight individuals.

Can persistent organic pollutants distinguish between two opposite metabolic phenotypes in lean Koreans?

AIMS

This study investigated the association of persistent organic pollutants (POPs), an emerging new risk factor for type 2 diabetes and the metabolic syndrome, with the presence of opposite phenotypes of glucose and lipid metabolism among normal-weight Koreans of similar body composition.

METHODS

Fifty subjects, randomly selected from an ongoing community-based cohort study, from two opposite phenotype groups - metabolically unhealthy normal weight (MUHNW) and metabolically healthy normal weight (MHNW) - were matched for waist circumference, visceral fat mass and demographic variables, then compared for serum concentrations of POPs.

RESULTS

Most POPs (10 out of 13 compounds) were present in higher serum concentrations in the MUHNW than in the MHNW. In particular, serum concentrations of all compounds of the organochlorine pesticide class were 2.2 to 4.7 times higher in cases than in controls. Compared with the lowest tertile of summary measures of POPs, Odds ratios (95% confidence interval) for the second and third tertiles were 7.4 (1.9-29.4) and 10.4 (2.6-41.2), respectively. Adjusting for possible confounders did not change the results.

CONCLUSION

Taken altogether, these findings from the present and previous studies suggest that increased serum POP concentrations may play an important role in the development of unhealthy metabolic phenotypes in lean people.

Evolutionarily adapted hormesis-inducing stressors can be a practical solution to mitigate harmful effects of chronic exposure to low dose chemical mixtures

Although the toxicity of synthetic chemicals at high doses is well known, chronic exposure to low-dose chemical mixtures has only recently been linked to many age-related diseases. However, it is nearly impossible to avoid the exposure to these low-dose chemical mixtures as humans are exposed to a myriad of synthetic chemicals as a part of their daily lives. Therefore, coping with possible harms due to low dose chemical mixtures is challenging. Interestingly, within the range of environmental exposure, disease risk does not increase linearly with increasing dose of chemicals, but often tends to plateau or even decrease with increasing dose. Hormesis, the over-compensation of various adaptive responses through cellular stresses, is one possible mechanism for this non-linearity. Although the hormetic effects of synthetic chemicals or radiation have long been debated in the field of toxicology, the hormesis concept has recently been generalized in the field of molecular biology; similar to responses to synthetic chemicals, mild to moderate intermittent stressors from any source can induce hormetic responses. Examples of stressors are exercise, calorie restriction, intermittent fasting, cognitive stimulation, and phytochemicals. Mitohormesis is hormesis induced by such stressors through mitochondrial retrograde signalling including the increased production of mild reactive oxygen species. Xenohormesis is phytochemical-induced hormesis, reflective of a mutualistic relationship between plant and animals. As humans had repeated exposure to all of these stressors during their evolution, the hormetic effects of these health behaviours may be considered to be evolutionarily adapted. Although hormesis induced by synthetic chemicals occurs in humans, such hormesis may not be recommended to the public due to unresolved issues on safety including the impossibility of control exposure. However, the use of personal health behaviors which enhance mitohormetic- or xenohormetic-stress can be readily incorporated into everyone's daily lives as a practical way to counteract harmful effects of unavoidable low-dose chemical mixtures.

Metabolic syndrome is associated with exposure to organochlorine pesticides in Anniston, AL, United States

The Anniston Community Health Survey, a cross-sectional study, was undertaken in 2005-2007 to study environmental exposure to polychlorinated biphenyl (PCB) and organochlorine (OC) pesticides and health outcomes among residents of Anniston, AL, United States. The examination of potential risks between these pollutants and metabolic syndrome, a cluster of cardiovascular risk factors (i.e., hypertension, central obesity, dyslipidemia and dysglycemia) was the focus of this analysis. Participants were 548 adults who completed the survey and a clinic visit, were free of diabetes, and had a serum sample for clinical laboratory parameters as well as PCB and OC pesticide concentrations. Associations between summed concentrations of 35 PCB congeners and 9 individual pesticides and metabolic syndrome were examined using generalized linear modeling and logistic regression; odds ratios (OR) and 95% confidence intervals (CI) are reported. Pollutants were evaluated as quintiles and as log transformations of continuous serum concentrations. Participants were mostly female (68%) with a mean age (SD) of 53.6 (16.2) years. The racial distribution was 56% white and 44% African American; 49% met the criteria for metabolic syndrome. In unadjusted logistic regression, statistically significant and positive associations across the majority of quintiles were noted for seven individually modeled pesticides (p,p'-DDT, p,p'-DDE, HCB, β-HCCH, oxychlor, tNONA, Mirex). Following adjustment for covariables (i.e., age, sex, race, education, marital status, current smoking, alcohol consumption, positive family history of diabetes or cardiovascular disease, liver disease, BMI), significant elevations in risk were noted for p,p'-DDT across multiple quintiles (range of ORs 1.61 to 2.36), for tNONA (range of ORs 1.62-2.80) and for p,p'-DDE [OR (95% CI)] of 2.73 (1.09-6.88) in the highest quintile relative to the first. Significant trends were observed in adjusted logistic models for log10 HCB [OR=6.15 (1.66-22.88)], log10 oxychlor [OR=2.09 (1.07-4.07)] and log10 tNONA [3.19 (1.45-7.00)]. Summed PCB concentrations were significantly and positively associated with metabolic syndrome only in unadjusted models; adjustment resulted in attenuation of the ORs in both the quintile and log-transformed models. In conclusion, several OC pesticides were found to have significant associations with metabolic syndrome in the Anniston study population while no association was observed for PCBs.

Human adipose tissue levels of persistent organic pollutants and metabolic syndrome components: Combining a cross-sectional with a 10-year longitudinal study using a multi-pollutant approach

We aimed to assess the influence of long-term exposure to POPs on the risk of metabolic syndrome, combining a cross-sectional with a 10-year longitudinal follow-up design. Residues of eight POPs were quantified in adipose tissue samples from 387 participants recruited between 2003 and 2004 in Granada province (Spain). The outcome ("metabolically compromised") was defined as having ≥1 diagnosis of type 2 diabetes, hypertension, hypertriglyceridemia, and/or low HDL cholesterol. The cross-sectional analysis was conducted in the initial cohort, while the 10-year longitudinal analysis was conducted in those 154 participants free of any of the so-mentioned metabolic diseases and classified as "metabolically healthy" at recruitment. Statistical analyses were performed using single and multi-pollutant approaches through logistic and Cox regression analyses with elastic net penalty. After adjusting for confounders, β-hexachlorocyclohexane (β-HCH) and hexachlorobenzene (HCB) were independently associated with an increased risk of being metabolically compromised (unpenalized ORs=1.17, 95% CI=1.01-1.36 and 1.17, 95% CI=0.99-1.38, respectively). Very similar results were found in the 10-year longitudinal analysis [HRs=1.28, 95% CI=1.01-1.61 (β-HCH); 1.26, 95% CI=1.00-1.59 (HCB)] and were in line with those obtained using elastic net regression. Finally, when the arithmetic sum of both compounds was used as independent variable, risk estimates increased to OR=1.25, 95% CI=1.03-1.52 and HR=1.32, 95% CI=1.02-1.70. Our results suggest that historical exposure to HCB and β-HCH is consistently associated with the risk of metabolic disorders, and that these POPs might be partly responsible for the morbidity risk traditionally attributed to age and obesity.

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.

Different associations of albuminuria with total and cardiovascular mortality by concentrations of persistent organic pollutants in the elderly

Epidemiologic studies have indicated that albuminuria is associated with mortality from all causes and cardiovascular disease (CVD), with substantial heterogeneity. We evaluated if the associations of urine albumin creatinine ratio (ACR) with all-cause and CVD mortality differed depending on serum concentrations of persistent organic pollutants (POPs), strong lipophilic chemical mixtures with very long half-lives, which are recently linked to many degenerative diseases. Study subjects were participants of the National Health and Nutrition Examination Survey 1999-2004 who were 60 years or older at baseline (n=1215 and 1067 for organochlorine pesticides (OCPs) and other POPs, respectively). They were followed-up through 2011 (mean follow-up periods: 8.1 and 8.0 years for OCPs and other POPs, respectively). The associations between the ACR and all-cause mortality significantly differed by the serum levels of POPs, especially organochlorine pesticides (OCPs; P_interaction<0.01). Stratified analyses indicated that the associations between ACR and all-cause mortality became stronger as the serum levels of OCPs increased. Among the elderly with the highest tertile of OCPs, the adjusted hazard ratios were 1.0, 1.1, and 2.9 (P_trend<0.01) across the categories of ACR (<10, 10-<30, and ≥30mg/g); however, ACR was not clearly related to mortality among the elderly with the lowest tertile of OCPs. CVD mortality showed similar interactions, as noted for all-cause mortality (P_interaction<0.01). The different associations between albuminuria and mortality by the serum OCP levels and the little association among the elderly with low serum OCPs levels suggest that OCPs play an important role in albuminuria-related death risk. However, these findings need to be replicated in other cohort studies.

Weight loss technology for people with treated type 2 diabetes: a randomized controlled trial

Background

The prevalence of type 2 diabetes is increasing in worldwide despite the development of new treatment methods. Aim of the study was to evaluate a weight loss method on body composition, glycemic, lipid and hormone profiles, blood pressure and reactive oxygen species in people with treated type 2 diabetes.

Methods

A 24-week open, prospective, randomized, controlled clinical trial including 272 adult patients with treated type 2 diabetes was performed. The patients were divided in two groups: Main group consisted of 208 patients who followed a method including a calorie restriction diet and optimal physical activity; Control included 64 patients who received conventional drug treatment with weight loss. Main Outcome Measures were weight loss, fasting glucose and 2-hour oral glucose tolerance test (OGTT), HbA1c. Secondary endpoints were blood pressure, lipid and insulin blood levels.

Results

At 24 weeks, patients in Main weight lost between 8-18 kg (10–21%); their body mass index significantly decreased (-4.2 kg/m2) as well as their waist circumference (-13 cm) compared to Control. In Main weight loss was achieved fatty mass reduction. In Main fasting glucose and OGTT, HbA1c, blood pressure, reactive oxygen species decreased significantly, whereas hemoglobin levels and heel bone mineral density increased. In Main blood insulin levels decreased by 72.0%, cortisol levels decreased by 40.7%, while testosterone levels in men increased by 2.4 times from baseline. The application of the weight loss method led to a decrease in drug doses leading to their complete withdrawal.

Conclusions

The results of this study show the beneficial role of a weight loss method in improving glycemic, lipid and hormone profiles, electrolyte and biochemical indices, blood pressure, reactive oxygen species and bone mineral density in patients with treated type 2 diabetes.

Trial registration

ClinicalTrials.gov Identifier: NCT02503865. Retrospectively registered November 2015.

Endocrine-disrupting polychlorinated biphenyls in metabolically healthy and unhealthy obese subjects before and after weight loss: difference at the start but not at the finish

BACKGROUND

A subset of obese individuals does not exhibit metabolically unfavorable features; this group is referred to as metabolically healthy obese (MHO). Serum concentrations of polychlorinated biphenyls (PCBs), which are chemicals with endocrine-disrupting properties, have been shown to be lower in MHO than in metabolically unhealthy obese (MUO).

OBJECTIVE

We studied PCB serum concentrations during and after weight loss and their relation with metabolic health.

DESIGN

We determined metabolic health features (weight, blood pressure, lipids, inflammation, and glucose metabolism) and serum PCB concentrations of 27 PCBs in a cohort of 184 overweight and obese subjects. Metabolic health was evaluated with the use of the criteria of the metabolic syndrome (MetS) [metabolic syndrome according to Adult Treatment Panel III criteria present (MetS+) or metabolic syndrome according to Adult Treatment Panel III criteria absent (MetS−)] or with extended criteria with inflammation and insulin resistance taken into account (MUO compared with MHO). Participants were treated with lifestyle counseling or bariatric surgery. A metabolic and toxicological re-evaluation was performed after 6 and 12 mo.

RESULTS

At baseline, serum ΣPCB concentrations were significantly higher in MUO than in MHO (ΣPCBs: 138 ±105 compared with 365 ± 481 ng/g lipid weight; P = 0.01) but not in MetS+ compared with MetS− subjects. No difference was detected in the percentage increase in PCB serum concentrations in MetS+ compared with MetS− subjects (median: 58% compared with 43% and 31% compared with 69% at 6 and 12 mo, respectively). The comparison of persistent with resolved MetS and MUO did not reveal any difference in ΣPCB concentration increments (median: 49% compared with 58% at 12 mo for MUO; P > 0.05). In a regression model with age, smoking, and body mass index corrected for, PCB serum concentrations at baseline were not predictive of the persistence or resolution of a metabolically unfavorable state.

CONCLUSION

Our study indicates that the increment in serum concentrations of PCBs does not differ according to metabolic health and does not seem to influence the beneficial metabolic health effects of weight loss. This study was registered at clinicaltrials.gov at NCT01778868.

The Effect of Exposure to Persistent Organic Pollutants on Metabolic Health among KOREAN Children during a 1-Year Follow-Up

Previous evidence suggests the potential for adverse effects of persistent organic pollutants (POPs) on metabolic health even at low-dose exposure levels common among the general population, but there is less evidence of these associations among children. Therefore, as part of a prospective cohort study, 214 children were measured for POPs exposure. After the 1-year follow-up, we assessed the effect of circulating POPs exposure among 158 children aged 7-9 years (at baseline) on the change of metabolic components of metabolic syndrome using multiple regression analysis. In addition, we calculated the continuous metabolic syndrome (cMetS) score and assessed the variation among individuals by POPs exposure. The concentrations of marker polychlorinated biphenyls (PCBs) were significantly associated with increased change in diastolic blood pressure (BP) and triglyceride levels during a 1-year follow-up, after controlling for sex, age, household income, and change in body mass index. Total PCBs also showed a marginal association with increasing cMetS score from the baseline. Of the metabolic components, change in diastolic BP over time showed a notable association with specific PCBs, but no association with organochlorine pesticides. Here, we found that low-dose exposures to PCBs among children in the general population could negatively influence metabolic health, particularly diastolic BP. Increased disease sensitivity during childhood can continue to adulthood, thus, these results support the need for continuous assessment of the health impact of POPs.