Public healthcare costs associated with long-term exposure to mixtures of persistent organic pollutants in two areas of Southern Spain: A longitudinal analysis.

BACKGROUND: Polychlorinated biphenyls and organochlorine pesticides are persistent organic pollutants (POPs) that had been banned or restricted in many countries, including Spain. However, their ubiquity still poses environmental and human health threats. OBJECTIVE: To longitudinally explore public healthcare costs associated with long-term exposure to a mixture of 8 POPs in a cohort of residents of two areas of Granada Province, Southern Spain. METHODS: Longitudinal study in a subsample (n = 385) of GraMo adult cohort. Exposure assessment was performed by analyzing adipose tissue POP concentrations at recruitment. Average primary care (APC) and average hospital care (AHC) expenditures of each participant over 14 years were estimated using the data from their medical records. Data analyses were performed by robust MM regression, weighted quantile sum regression (WQS) and G-computation analysis. RESULTS: In the adjusted robust MM models for APC, most POPs showed positive beta coefficients, being Hexachlorobenzene (HCB) significantly associated (ß: 1.87; 95% Confidence interval (95%CI): 0.17, 3.57). The magnitude of this association increased (ß: 3.72; 95%CI: 0.80, 6.64) when the analyses were restricted to semi-rural residents, where ß-HCH was also marginally-significantly associated to APC (ß: 3.40; 95%CI: -0.10, 6.90). WQS revealed a positive but non-significant mixture association with APC (ß: 0.14; 95%CI: -0.06, 0.34), mainly accounted for by ß-HCH (54%) and HCB (43%), that was borderline-significant in the semi-rural residents (ß: 0.23; 95%CI: -0.01, 0.48). No significant results were observed in G-Computation analyses. CONCLUSION: Long-term exposure to POP mixtures might represent a modifiable factor increasing healthcare costs, thus affecting the efficiency of the healthcare systems. However, and owing the complexity of the potential causal pathways and the limitations of the present study, further research is warranted to fully elucidate ascertain whether interventions to reduce human exposure should be considered in healthcare policies.

Trace elements concentration in adipose tissue and the risk of incident type 2 diabetes in a prospective adult cohort.

The aim of this work was to study the associations of adipose tissue trace element concentrations with type 2 diabetes (T2DM) incidence over a 16-year follow-up period in an adult cohort from Southern Spain. 16-year T2DM incidence was gathered from hospital records. Chemical analyses of Cr, V, Zn, Fe, Cu and Se in adipose tissue were performed using inductively coupled plasma mass spectrometry. Multivariable Cox-regression models were used. Complementary cross-sectional analyses with markers of glucose homeostasis at recruitment were performed by multivariable linear regression. Out of 214 participants, 39 developed T2DM during the follow-up. Adipose tissue concentrations of Fe (HR = 1.97, 95% CI: 0.99 to 2.58, p = 0.057), Cr (HR = 1.58, 95% CI: 1.07-2.33, p = 0.022) and Cu (HR = 1.61, 95% CI: 1.01-2.58, p = 0.046) were individually associated with T2DM incidence. When Fe, Cr and Cu were simultaneously entered in a model, only Cr was significantly associated with T2DM incidence (HR = 1.68, 95% CI: 1.02-2.76, p = 0.041). Furthermore, adipose tissue V (ß = 0.283, p = 0.004) and Zn (ß = 0.217, p = 0.028) concentrations were positively associated with ß-pancreatic cell function (HOMA-ß), while Se showed an inverse association (ß = -0.049, p = 0.027). Although further research is warranted on the potential mechanisms of action, our results suggest that adipose tissue concentrations of certain trace elements (particularly Fe, Cr and Cu) are associated with the risk of incident T2DM, while V and Zn might have a protective effect. These biomarkers might complement prediction algorithms and contribute to identify patients with an increased risk of T2DM.

Associations of serum phthalate metabolites with thyroid hormones in GraMo cohort, Southern Spain.

The general population is continuously exposed to phthalates via various consumer products. Epidemiological research relating phthalate exposure to thyroid function during non-developmental periods is limited. This study aimed to investigate the associations between specific serum phthalate metabolites and indicators of thyroid function in adults. We measured 10 serum phthalate metabolites and thyroid hormones - total triiodothyronine (TT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH) - in a subsample of 207 adults from the GraMo cohort. This subsample was made up of men and women (in equal proportions) of middle age (49 ± 17 years) and from Southern Spain (province of Granada). Data on age, sex, body mass index, residence area, tobacco use, alcohol consumption and attained education were obtained from a questionnaire. Phthalate metabolites were log-transformed and categorized into tertiles. Cross-sectional associations of each metabolite with thyroid hormones were analyzed using multivariable-adjusted linear regression models. The mixture effect of metabolite phthalates was assessed using weighted quantile sum regression. After multivariable-adjustment, the following phthalate metabolites were significantly associated with TT3 in a dose-response manner: MMP (ß = 0.90: 95% confidence interval 0.68,1.12), MEP (ß = 0.67: 0.44, 0.90), MiBP (ß = 0.49: 0.21, 0.77), MiDP (ß = 0.27: 0.03, 0.52), MBzP (ß = 0.51: 0.28, 0.73), MEHP (ß = -0.59: -0.82, -0.35) and MiNP (ß = -0.43: -0.71, -0.14), when comparing highest vs. lowest exposed. The sum of all metabolites was also linked to FT4 levels. No significant associations were observed for TSH except for MiNP. Although phthalate metabolites with different molecular weight showed opposite associations, overall metabolite concentrations seem to associate with increased TT3 and FT4 serum levels. The cross-sectional nature of this analysis limits causal inference.

Historical exposure to persistent organic pollutants and cardiovascular disease: A 15-year longitudinal analysis focused on pharmaceutical consumption in primary care.

BACKGROUND: Despite restrictions on their production and use, most of the population is still exposed to Persistent Organic Pollutants (POPs), including organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). These chemicals are thought to contribute to the aetiology of highly prevalent chronic conditions, such as cardiovascular diseases (CVDs), although current evidences are still controversial. OBJECTIVES: To explore the potential contribution of historical POP exposure to 15-year pharmaceutical consumption in relation to CVD. METHODS: This study is framed within GraMo adult cohort. Participants (n = 387) were recruited in two hospitals in Granada province, Southern Spain (2003-2004). Historical exposure to 5 OCPs and 3 non-dioxine-like PCBs was estimated by analysing adipose tissue concentrations at recruitment. Pharmaceutical consumption from recruitment until year 2017 was quantified by reviewing dispensation databases. Average consumption increase (ACI) in CVD medication was calculated by subtracting average consumption in 2002 to the average yearly consumption during follow-up. ACI was expressed as Defined Daily Dose (DDD)/year units. Data analyses were carried out using a multivariable multinomial logistic regression and weighted quantile sum regression (WQS), with ACI categorized in quartiles (Q) as the dependent variable. RESULTS: Concentrations of most pollutants showed a positive trend with the quartiles of ACI. Particularly, PCB-153 showed increasing and statistically significant odds ratios (ORs) for Q2 (OR: 1.27, 95% confidence interval (CI): 1.07-1.52), Q3 (OR: 1.49, 95 %CI: 1.17-1.88) and Q4 (OR: 1.42, 95 %CI: 1.13-1.78) vs Q1. Similarly, beta-hexachlorocyclohexane (ß-HCH) also showed increasing ORs, that reached statistical significance in Q4 (OR: 1.36, 95 %CI: 1.06-1.74) vs Q1. These findings were corroborated by WQS analyses, that revealed a significant mixture effect, predominantly accounted for by PCB-153 and ß-HCH. DISCUSSION: Our results suggest that long-term POP exposure might represent a modifiable risk factor for CVD. These findings are relevant for public health campaigns and management, since pharmaceutical consumption is considered an indicator of both morbidity and health expenditure.

Adipose Tissue Redox Microenvironment as a Potential Link between Persistent Organic Pollutants and the 16-Year Incidence of Non-hormone-Dependent Cancer.

We aimed to assess the relationships among the adipose tissue's (AT) oxidative microenvironment, in situ accumulated persistent organic pollutant (POP) concentrations, and cancer development. POP and oxidative stress levels were quantified in AT samples from 382 adults recruited within the GraMo cohort (2003-2004) in Granada (Spain). The 16-year cancer incidence was ascertained by reviewing health/administrative databases. Cox-regression models and mediation analyses were performed. The enzymes superoxide dismutase (SOD) and glutathione reductase (GRd) were positively associated with the risk of non-hormone-dependent (NHD) cancer [adjusted hazard ratio (HR) 1.76; 95% confidence interval (CI): 1.17, 2.64 and HR 2.35; 95% CI: 1.41, 3.94, respectively]. After adjustment for covariates, polychlorinated biphenyl-138 (PCB-138) (HR 1.78; 95% CI: 1.03, 3.09), ß-hexachlorocyclohexane (ß-HCH) (HR 1.70; 95% CI: 1.09, 2.64), and hexachlorobenzene (HR 1.54; 95% CI: 1.02, 2.33) were also positively associated with the risk of NHD cancer. Although confidence intervals included the null value, probably because of the modest number of cancer cases, we observed a potential mediation effect of SOD and GRd on the associations between ß-HCH and the risk of NHD tumors (percent mediated = 33 and 47%, respectively). Our results highlight the relevance of human AT's oxidative microenvironment as a predictor of future cancer risk as well as its potential mediating role on POP-related carcinogenesis. Given their novelty, these findings should be interpreted with caution and confirmed in future studies.

Associations of accumulated selected persistent organic pollutants in adipose tissue with insulin sensitivity and risk of incident type-2 diabetes.

Continuous exposure to low doses of persistent organic pollutant (POPs), such as those occurring in the general population, might contribute to the burden of type 2 diabetes mellitus (T2DM). However, evidences from longitudinal studies are scarce. We aimed to explore the associations of accumulated POP exposure with the development of T2DM by means of 1) longitudinal associations with the 16-year incidence of the disease, and 2) complementary cross-sectional analyses with markers of glucose homeostasis at recruitment. Organochlorine pesticide and polychlorinated biphenyl (PCB) concentrations were analyzed in adipose tissue samples and incident T2DM cases were retrieved from clinical records. Homeostatic model assessment values of insulin sensitivity/resistance and ß-cell function at recruitment were calculated. Linear and Cox-regression models were performed. In individuals with normal weight/overweight (n = 293), we observed positive dose-response relationships between the studied POPs and T2DM risk, particularly for hexachlorobenzene (HCB) [hazard ratio (HR): 3.96 for 4th quartile versus 1st quartile (Q1); confidence interval (CI) 95%: 0.79, 19.71]. PCB-180 showed a positive but seemingly non-linear association with T2DM risk [HR of 3er quartile (Q3) versus Q1: 6.48; CI 95%: 0.82, 51.29]. Unadjustment for body mass index considerably increased the magnitude of the associations. In the cross-sectional study (n = 180), HCB and PCB-180 were inversely associated with insulin sensitivity and positively associated with insulin resistance parameters. Our results suggest that a higher burden of specific POPs in adipose tissue may disrupt glucose homeostasis, possibly contributing to increase T2DM risk, especially in non-obese adults.

Adipose tissue cadmium concentrations as a potential risk factor for insulin resistance and future type 2 diabetes mellitus in GraMo adult cohort.

Adipose tissue has been recently highlighted as a promising matrix for evaluation of cadmium's (Cd) long-term exposure although not frequently considered in epidemiological studies. The association between Cd exposure and type 2 Diabetes Mellitus (T2DM) remains unclear. This work aimed to explore the association between adipose tissue Cd levels and T2DM incidence over a 16-year follow-up in an adult cohort from Southern Spain considering smoking status. We also performed complementary cross-sectional analyses focused on subclinical markers of glucose homeostasis at recruitment. Clinical information was obtained from hospital databases. Socio-demographic characteristics, lifestyle and diet were collected by face-to-face interviews. Homeostatic model assessment (HOMA) values of insulin sensitivity/resistance and ß-cell function were calculated using fasting serum glucose, insulin, and C-peptide levels at recruitment. Adipose tissue Cd concentrations were quantified by inductively coupled plasma mass spectrometry. Statistical analyses were performed by means of Cox-regression and multivariable linear regression models. Participants in the 4th quartile (Q4) of Cd concentrations showed a non statistically-significant increased T2DM risk (Hazard Ratio (HR) Q4 vs Q1: 1.97; 95% Confidence Interval (CI): 0.69, 5.66). This association was particularly strong and suggestive in current smokers (HR: 2.19; 95% CI: 0.98, 4.98). Interestingly, smokers in the 2nd tertile (T2) of adipose tissue Cd levels showed increased log-transformed insulin resistance (beta T2 vs T1: 0.52; 95% CI: 0.07, 0.97), as well as higher log-transformed insulin levels (beta T2 vs T1: 0.52; 95% CI: 0.08, 0.95). We found evidences supporting that Cd exposure, particularly from tobacco smoking, could be a risk factor for T2DM. In addition, our results support the potential relevance of adipose tissue as a matrix for Cd exposure assessment.

Associations of residential and occupational history with the distribution of persistent pollutant mixtures in adipose tissue samples.

This research aims to explore clusters of a mixture of 15 Persistent Toxic Substances (PTSs) in the adipose tissue of 227 individuals of an adult cohort from Granada Province (Southern Spain). Information about residence and occupation during participants lifetime was gathered by means of validated questionnaires. Clusters of pollutants in the study population were identified by Principal Component Analyses (PCA). PCA analyses revealed three major clusters of pollutants: PC1, representing predominantly an assortment of metal(loid)s, namely aluminium, arsenic, chromium, nickel and lead; PC2, including mostly Organochlorine Pesticides (OCPs), such as HCB, ß-HCH and p,p'-DDE; and PC3, gathering mainly a mixture of Polychlorinated Biphenyls (PCB-138, PCB-153 and PCB-180) and metals (cadmium, cobalt and chromium). The patterns of distribution of individual pollutants and their mixtures were explored through Geographic Information Systems and multivariable linear regression models. Living in rural areas was associated with decreased levels of the mixture of PCBs and metals. Residents of industrial and heavy traffic areas showed increased levels of the mixture of metal(loid)s. Those living in rural and semi-rural areas at recruitment had decreased levels of the OCP mixture. Occupational history related to agriculture and food industry was associated with increased levels of the mixture of metal(loid)s, whereas those who had been involved in motor and industrial activities showed increased levels of the OCP mixture. Participants who had worked in cleaning and housekeeping activities for long periods showed decreased levels of the mixture of PCBs and metals. Our research revealed suggestive clusters of exposure, that emphasized the need for further epidemiological studies to address the effect of environmental pollutants from a mixture perspective. Results also highlight the potential of adipose tissue as a matrix for exposure assessment to combinations of different families of contaminants.

Contribution of sociodemographic, occupational, lifestyle and dietary characteristics to the oxidative stress microenvironment in adipose tissue.

The present study was conceived on the basis of the few previous reports suggesting a potential relevance of the oxidative stress microenvironment in the adipose tissue, a biological matrix which is closely related to the development of several chronic pathologies. Thus, our aim was to describe the levels of enzymatic and non-enzymatic antioxidants and markers of oxidative damage in adipose tissue samples from a Spanish cohort, as well as their main sociodemographic, lifestyle, and dietary predictors. The study was conducted in a subsample (n = 271 adults) of GraMo cohort, recruited in Granada (Southern Spain). A face-to-face questionnaire was used to gather data regarding sociodemographic characteristics, lifestyle, dietary habits, health status, and perceived exposure to chemicals. We analyzed adipose tissue levels of lipid peroxidation (TBARS), total superoxide dismutase (SOD) activity, heme oxygenase-1 (HO-1) activity, and glutathione cycle biomarkers. Potential predictors of oxidative stress markers were assessed using stepwise multivariable linear regression analyses. SOD and TBARS levels were mainly related to sociodemographic and occupational characteristics, while the components of the glutathione cycle and HO-1 were predominantly associated with dietary habits. Men showed significantly lower levels of oxidative stress levels than women. In the regression models including only women, the use of oral contraceptive and hormonal therapy was associated with lower levels of oxidative stress, while the number of children was positively associated with increased oxidative biomarkers. Our results suggest that adipose tissue is potentially important matrix for the assessment of oxidative stress, which can be affected by specific environmental factors. These findings might be relevant for public health.

Influence of the HER2 Ile655Val polymorphism on trastuzumab-induced cardiotoxicity in HER2-positive breast cancer patients: a meta-analysis.

BACKGROUND: The HER2 655 A>G genetic variant has recently been associated with trastuzumab-induced cardiotoxicity in HER2 breast cancer patients. Considering previous results, the aim of our study was to validate the role of this polymorphism as a predictor of the cardiac toxicity of trastuzumab in breast cancer patients. METHODS: Our study population was composed of 78 HER2 breast cancer patients receiving trastuzumab. The HER2 655 A>G (rs1136201) genetic variant was genotyped using TaqMan allelic discrimination technology. Patients were classified on the basis of the occurrence of cardiotoxic events or the absence of cardiotoxic events during 1 year after the first infusion. RESULTS: The HER2 655 A>G polymorphism was significantly associated with cardiotoxicity: AG versus AA [P=0.012, odds ratio (OR)=5.12, 95% confidence interval (CI) 1.43-18.36], AG+GG versus AA (P=0.01, OR=5.72, 95% CI 1.50-21.76), AG versus AA+GG (P=0.005, OR=7.17, 95% CI 1.82-28.29). A meta-analysis combining these data with the results from previous studies confirmed this association. CONCLUSION: Our results support the role of the HER2 655 A>G polymorphism as a genetic marker of trastuzumab-induced cardiotoxicity in HER2-positive breast cancer patients.