Increase in metabolic syndrome-related hospitalizations in relation to environmental sources of persistent organic pollutants

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.

Serum concentrations of persistent organic pollutants and the metabolic syndrome in Akwesasne Mohawks, a Native American community

The metabolic syndrome (MetS) is a group of diseases that tend to occur together, including diabetes, hypertension, central obesity, cardiovascular disease and hyperlipidemia. Exposure to persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) has been associated with increased risk of development of several of the components of the MetS. The goal of this study is to determine whether the associations with POPs are identical for each of the components and for the MetS. The subject population was 601 Native Americans (Akwesasne Mohawks) ages 18 to 84 who answered a questionnaire, were measured for height and weight and provided blood samples for clinical chemistries (serum lipids and fasting glucose) and analysis of 101 PCB congeners and three OCPs [dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB) and mirex]. Associations between concentrations of total PCBs and pesticides, as well as various PCB congener groups with each of the different components of the MetS were determine so as to ask whether there were similar risk factors for all components of the MetS. After adjustment for other contaminants, diabetes and hypertension were strongly associated with lower chlorinated and mono-ortho PCBs, but not other PCB groups or pesticides. Obesity was most closely associated with highly chlorinated PCBs and was negatively associated with mirex. High serum lipids were most strongly associated with higher chlorinated PCBs and PCBs with multiple ortho-substituted chlorines, as well as total pesticides, DDE and HCB. Cardiovascular disease was not closely associated with levels of any of the measured POPs. While exposure to POPs is associated with increased risk of most of the various diseases comprising the MetS, the specific contaminants associated with risk of the component diseases are not the same.

Hazardous waste and health impact: a systematic review of the scientific literature

Waste is part of the agenda of the European Environment and Health Process and included among the topics of the Sixth Ministerial Conference on Environment and Health. Disposal and management of hazardous waste are worldwide challenges. We performed a systematic review to evaluate the evidence of the health impact of hazardous waste exposure, applying transparent and a priori defined methods. The following five steps, based on pre-defined systematic criteria, were applied. 1. Specify the research question, in terms of "Population-Exposure-Comparators-Outcomes" (PECO).

POPULATION

people living near hazardous waste sites; Exposure: exposure to hazardous waste; Comparators: all comparators; Outcomes: all diseases/health disorders. 2. Carry out the literature search, in Medline and EMBASE. 3. Select studies for inclusion: original epidemiological studies, published between 1999 and 2015, on populations residentially exposed to hazardous waste. 4. Assess the quality of selected studies, taking into account study design, exposure and outcome assessment, confounding control. 5. Rate the confidence in the body of evidence for each outcome taking into account the reliability of each study, the strength of the association and concordance of results.Fifty-seven papers of epidemiological investigations on the health status of populations living near hazardous waste sites were selected for the evidence evaluation. The association between 95 health outcomes (diseases and disorders) and residential exposure to hazardous waste sites was evaluated. Health effects of residential hazardous waste exposure, previously partially unrecognized, were highlighted. Sufficient evidence was found of association between exposure to oil industry waste that releases high concentrations of hydrogen sulphide and acute symptoms. The evidence of causal relationship with hazardous waste was defined as limited for: liver, bladder, breast and testis cancers, non-Hodgkin lymphoma, asthma, congenital anomalies overall and anomalies of the neural tube, urogenital, connective and musculoskeletal systems, low birth weight and pre-term birth; evidence was defined as inadequate for the other health outcomes. The results, although not conclusive, provide indications that more effective public health policies on hazardous waste management are urgently needed. International, national and local authorities should oppose and eliminate poor, outdated and illegal practices of waste disposal, including illegal transboundary trade, and increase support regulation and its enforcement.

Effect of birthplace on cardiometabolic risk among blacks in the Metabolic Syndrome Outcome Study (MetSO)

BACKGROUND

Metabolic syndrome poses an increased global burden of disease and causes immense financial burden, warranting heightened public health attention. The present study assessed the prevalence and severity of cardiometabolic risk among foreign-born versus US-born blacks, while exploring potential gender-based effects.

METHODS

A total of 1035 patients from the Metabolic Syndrome Outcome Study (Trial registration: NCT01946659) provided sociodemographic, medical history, and clinical data. General Linear Model (GLM) was used to assess the effects of birthplace and gender on cardiometabolic parameters, adjusting for age differences in the sample.

RESULTS

Of the sample, 61.6 % were foreign-born blacks (FBB) and 38.4 % were US-born blacks (USB). FBB had significantly lower BMI compared with USB (32.76 ± 0.35 vs. 35.41 ± 0.44, F = 22.57), but had significantly higher systolic blood pressure (136.70 ± 0.77 vs. 132.83 ± 0.98; F = 9.60) and fasting glucose levels than did USB (146.46 ± 3.37 vs. 135.02 ± 4.27; F = 4.40). Men had higher diastolic BP (76.67 ± 0.65 vs. 75.05 ± 0.45; F = 4.20), glucose (146.53 ± 4.48 vs. 134.95 ± 3.07; F = 4.55) and triglyceride levels (148.10 ± 4.51 vs. 130.60 ± 3.09; F = 10.25) compared with women, but women had higher LDL-cholesterol (109.24 ± 1.49 vs. 98.49 ± 2.18; F = 16.60) and HDL-cholesterol levels (50.71 ± 0.66 vs. 42.77 ± 0.97; F = 46.01) than did men.

CONCLUSIONS

Results showed that birthplace has a significant influence on cardiometabolic profiles of blacks with metabolic syndrome. Patients' gender also had an independent influence on cardiometabolic profile.

Obesogens, stem cells and the developmental programming of obesity

Obesogens are chemicals that directly or indirectly lead to increased fat accumulation and obesity. Obesogens have the potential to disrupt multiple metabolic signalling pathways in the developing organism that can result in permanent changes in adult physiology. Prenatal or perinatal exposure to obesogenic endocrine disrupting chemicals has been shown to predispose an organism to store more fat from the beginning of its life. For example, excess oestrogen or cortisol exposure in the womb or during early life resulted in an increased susceptibility to obesity and metabolic syndrome later in life. This review focuses on the effects of environmental chemicals, such as the model obesogen, tributyltin (TBT), on the development of obesity. We discuss evidence linking the obesogenic effects of TBT with its ability to activate the peroxisome proliferator-activated receptor gamma and stimulate adipogenesis. We also discuss how TBT and other environmental obesogens may lead to epigenetic changes that predispose exposed individuals to subsequent weight gain and obesity. This suggests that humans, who have been exposed to obesogenic chemicals during sensitive windows of development, might be pre-programmed to store increased amounts of fat, resulting in a lifelong struggle to maintain a healthy weight and exacerbating the deleterious effects of poor diet and inadequate exercise.

Predicting the risk of cardiovascular disease in people exposed to moderate to high levels of dioxin

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality worldwide. Dioxins can cause cardiovascular toxicity in experimental animals. The potential role of dioxin exposure as a preventable risk factor has attracted the attention of public health services, especially because dioxin exposure is a ubiquitous problem. We aimed to investigate and clarify the effect on CVD risk of moderate-to-high exposure to dioxins. This cross-sectional study investigated 914 residents without CVD near a deserted pentachlorophenol factory. CVD-related factors were measured to examine their associations with serum dioxin. We also investigated associations between serum dioxins and the Framingham risk score. Serum PCDD/F levels were significantly positively associated with CVD risk in both genders (Men: b=0.023, P<0.001; Women: b=0.005, P<0.001; All: b=0.013, P<0.001). After adjusting for confounding factors, participants with higher serum PCDD/F levels had a higher risk for CVD than did the reference group (serum PCDD/levels<9.8 pg WHO(98)-TEQ(DF)/g lipid) (25th to <50th percentile, adjusted odds ratio (AOR)=2.96 [95% confidence interval (CI)=1.13-7.75]; 50th to<75th percentile, AOR=3.37 [1.32-8.59]; ≥75th percentile, AOR=6.22 [2.47-15.63]). We hypothesize that accumulated dioxins heightens the cardiovascular risk.