Determinants of PFOA Serum Half-Life after End of Exposure: A Longitudinal Study on Highly Exposed Subjects in the Veneto Region.

BACKGROUND: Perfluoroalkyl substances (PFAS) are widely used, ubiquitous, and highly persistent man-made chemicals. Groundwater of a vast area of the Veneto Region (northeastern Italy) was found to be contaminated by PFAS from a manufacturing plant active since the late 1960s. As a result, residents were overexposed to PFAS through drinking water until 2013, mainly to perfluorooctanoic acid (PFOA). OBJECTIVES: The aim of the present study was to estimate the rates of decline in serum PFOA and their corresponding serum half-lives, while characterizing their determinants. METHODS: We investigated 5,860 subjects more than 14 years of age who enrolled in the second surveillance round of the regional health surveillance program. Two blood samples were collected between 2017 and 2022 (average time between measurements: 4 years). Serum PFOA excretion rates and half-lives were estimated based on linear mixed effect models, modeling subject-specific serum PFOA concentrations over time and correcting for background concentrations. For modeling determinants of half-life [age, sex, body mass index (BMI), smoking-habit, alcohol consumption, and estimated glomerular filtration rate (eGFR)], we added interaction terms between each covariate and the elapsed time between measurements. Perfluorooctanesulfonate (PFOS) and perfluorohexanesulfonic acid (PFHxS) apparent half-lives were also estimated. A separate analysis was conducted in children (n=480). All analyses were stratified by sex. RESULTS: Median initial serum concentrations of PFOA was 49 ng/mL (range: 0.5-1,090), with a median reduction of 62.45%. The mean estimated PFOA half-life was 2.36 years [95% confidence interval (CI): 2.33, 2.40], shorter in women (2.04; 95% CI: 2.00, 2.08) compared to men (2.83; 95% CI: 2.78, 2.89). Half-lives varied when stratified by some contributing factors, with faster excretion rates in nonsmokers and nonalcohol drinkers (especially in males). CONCLUSIONS: This study, to our knowledge the largest on PFOA half-life, provides precise estimates in young adults whose exposure via drinking water has largely ceased. For other PFAS, longer half-lives than reported in other studies can be explained by some ongoing exposure to PFAS via other routes. https://doi.org/10.1289/EHP13152.

Estimation of per- and polyfluoroalkyl substances (PFAS) half-lives in human studies: a systematic review and meta-analysis.

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) constitute a heterogeneous group of synthetic compounds widely used in industrial applications. The estimation of PFAS half-life (t1/2) is essential to quantify their persistence, their toxicity and mechanism of action in humans. OBJECTIVES: The purpose of this review is to summarize the evidence on PFAS half-lives in humans from the available literature, and to investigate the limitations and uncertainties characterizing half-life estimation. METHODS: The search was conducted on PubMed, Scopus, and Embase databases up to July 03, 2023 and was aimed at identifying all papers that estimated PFAS half-life in human populations. We excluded studies on temporal trends or providing estimates of half-life based solely on renal clearance. As persistent and ongoing exposures can influence half-life estimation, we decided to include only studies that were conducted after the main source of exposure to PFAS had ceased. A random-effects meta-analysis was conducted on studies that reported perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS) or perfluorohexanesulfonic acid (PFHxS) half-life estimation. Risk of bias was evaluated using the OHAT tool. RESULTS: A total of 13 articles were included in the review, with 5 studies conducted in exposed general populations and 8 studies conducted in exposed workers; the estimated mean half-life ranged from 1.48 to 5.1 years for PFOA, from 3.4 to 5.7 years for total PFOS, and from 2.84 to 8.5 years for PFHxS. High heterogeneity among studies was observed; potential reasons include the variability among the investigated populations, discrepancies in considering ongoing exposures, variability in PFAS isomeric compositions, accounting for background exposure, time since exposure stopped and methods used for half-life estimation. DISCUSSION: Despite the efforts made to better understand PFAS toxicokinetics, further studies are needed to identify important characteristics of these persistent chemicals. Biomonitoring studies should focus on persistent and unaccounted sources of exposure to PFAS and on individual characteristics potentially determining half-life, to ensure accurate estimates.

Migrant status disparities in blood pressure: a multiple mediation analysis of modifiable factors.

BACKGROUND: We examined differences in blood pressure (BP) levels between first-generation immigrants and natives in adult residents in Northeast Italy, and investigated the role of lifestyle behaviors, body mass index (BMI), and education as potentially modifiable mediating factors. METHODS: We included 20-69-year-old participants from the Health Surveillance Program of the Veneto Region (n = 37,710). Immigrants born in a high migratory pressure country (HMPC) were further grouped into geographical macro-areas. The outcomes were systolic BP (SBP) and hypertension. Multiple mediation analyses were performed to determine the contribution of each mediator of the SBP/migrant status association. RESULTS: Of the 37,380 subjects included, 8.7% were born in an HMPC. BMI, education, alcohol, sweets and meat consumption were included as potential mediators. A small advantage in SBP was seen for immigrants compared to natives (ß = - 0.71,95%CI - 1.30; - 0.10). The direct effect (net of the covariates) of immigrant status on SBP was a reduction of 1.62 mmHg (95%CI - 2.25; - 0.98). BMI played the highest suppressive role (ß = 1.14,95%CI 0.99; 1.35), followed by education. Alcohol consumption amplified the health advantage of immigrants. The suppressing effect of BMI was particularly evident among women and North Africans compared to natives. Similar results were seen for hypertension rates. CONCLUSIONS: Although causation cannot be proven given the cross-sectional design, our findings identify BMI as the most effective target to preserve the health advantage of immigrants with respect to BP levels.

Adult first-generation immigrants and cardiovascular risk factors in the Veneto Region, Northeast Italy.

Introduction: The health condition of immigrants traditionally follows a transition from a low disease occurrence to the epidemiological profile of the deprived groups in the host country. In the Europe, studies examining differences in biochemical and clinical outcomes among immigrants and natives are lacking. We examined differences in cardiovascular risk factors between first-generation immigrants and Italians, and how migration pattern variables could affect health outcomes. Material and methods: We included participants between 20 and 69 years recruited from a Health Surveillance Program of the Veneto Region. Blood pressure (BP), total cholesterol (TC) and LDL cholesterol levels were measured. Immigrant status was defined by being born in a high migratory pressure country (HMPC) and subdivided by geographical macro-areas. We used generalized linear regression models to investigate differences between these outcomes among immigrants compared to native-born, adjusting for age, sex, education, BMI, alcohol consumption, smoking status, food consumption, salt consumption in the BP analysis and the laboratory in charge for cholesterol analysis. Within immigrant subjects, the results were stratified by variables of the migration pattern: age at immigration and length of residence in Italy. Results: Thirty seven thousand three hundred and eighty subjects were included in the analysis, 8.6% were born in an HMPC. Heterogeneous results were seen by the macro-areas of origin and sex, with male immigrants from CE Europe (ß = 8.77 mg/dl) and Asia (ß = 6.56 mg/dl) showing higher levels of TC than native-born, while female immigrants from Northern Africa showed lower levels of TC (ß = -8.64 mg/dl). BP levels were generally lower among immigrants. Immigrants residing in Italy for more than 20 years had lower levels of TC (ß = -2.9 mg/dl) than native-born. In contrast, immigrants who arrived <20 years ago or arrived older than 18 years had higher levels of TC. This trend was confirmed for CE Europeans and was inverted for Northern Africans. Conclusions: The large heterogeneity in the results depending on sex and macro-area of origin indicates the need for targeted intervention in each specific immigrant group. The results confirm that acculturation leads to a convergence toward the epidemiological profile of the host population that depends on the starting condition of the immigrant group.

The Association Between Pediatric COVID-19 Vaccination and Socioeconomic Position: Nested Case-Control Study From the Pedianet Veneto Cohort.

BACKGROUND: The success of pediatric COVID-19 vaccination strongly depends on parents' willingness to vaccinate their children. To date, the role of socioeconomic position (SEP) in pediatric COVID-19 vaccination has not been thoroughly examined. OBJECTIVE: We evaluated the association between COVID-19 vaccination and SEP in a large pediatric cohort. METHODS: A case-control study design nested into a pediatric cohort of children born between 2007 and 2017, living in the Veneto Region and followed up to at least January 1, 2022, was adopted. Data on children were collected from the Pedianet database and linked with the regional COVID-19 registry. Each child vaccinated with at least one dose of any COVID-19 vaccine between July 1, 2021, and March 31, 2022, was matched by sex, year of birth, and family pediatrician to up to 5 unvaccinated children. Unvaccinated children with a positive outcome on the swab test within 180 days before the index date were excluded from the analyses. Children were geo-referenced to determine their area deprivation index (ADI)-a social and material deprivation measure calculated at the census block level and consisting of 5 socioeconomic items. The index was then categorized in quintiles based on the regional ADI level. The association between ADI quintiles and vaccination status was measured using conditioned logistic regression models to estimate odds ratios and the corresponding 95% CIs. Quantile-g-computation regression models were applied to develop a weighted combination of the individual items to estimate how much each component influenced the likelihood of vaccination. All analyses were stratified by age at vaccination (5-11 and 12-14 years). RESULTS: The study population consisted of 6475 vaccinated children, who were matched with 32,124 unvaccinated children. Increasing area deprivation was associated with a lower probability of being vaccinated, with approximately a linear dose-response relationship. Children in the highest deprivation quintile were 36% less likely to receive a COVID-19 vaccine than those with the lowest area deprivation (95% CI 0.59-0.70). The results were similar in the 2 age groups, with a slightly stronger association in 5-11-year-old children. When assessing the effects of the weighted combination of the individual items, a quintile increase was associated with a 17% decrease in the probability of being vaccinated (95% CI 0.80-0.86). The conditions that influenced the probability of vaccination the most were living on rent, being unemployed, and being born in single-parent families. CONCLUSIONS: This study has shown a significant reduction in the likelihood of receiving a COVID-19 vaccine among children living in areas characterized by a lower SEP. Findings were robust among multiple analyses and definitions of the deprivation index. These findings suggest that SEP plays an important role in vaccination coverage, emphasizing the need to promote targeted public health efforts to ensure global vaccine equity.

Associations between Mixture of Perfluoroalkyl Substances and Lipid Profile in a Highly Exposed Adult Community in the Veneto Region.

BACKGROUND: Residents of a large area in the Veneto Region (Northeastern Italy) were exposed to drinking water contaminated by perfluoroalkyl substances (PFAS) for decades. While exposure to PFAS has been consistently associated with elevated serum lipids, combined exposures to multiple PFASs have been poorly investigated. Utilising different statistical approaches, we examine the association between chemical mixtures and lipid parameters. METHODS: Cross-sectional data from the regional health surveillance program (34,633 individuals aged 20-64 years) were used to examine the combined effects of PFAS mixture (Perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA) and perfluorohexane sulfonate (PFHxS)) on total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). Weighted Quantile Sum (WQS) regression, Quantile-based G-computation (Q-Gcomp) and Bayesian Kernel Machine Regression (BKMR) were used based on their ability to handle highly correlated chemicals. RESULTS: We observed that each quartile increase in the WQS index was associated with an increase in the levels of TC (ß: 4.09, 95% CI: 3.47-4.71), HDL-C (ß: 1.13, 95% CI: 0.92-1.33) and LDL-C (ß: 3.14, 95% CI: 2.65-3.63). Q-Gcomp estimated that a quartile increase in the PFAS mixture was associated with increased TC (ψ: 4.04, 95% CI 3.5-4.58), HDL-C (ψ: 1.07, 95% CI 20.87-1.27) and LDL-C (ψ: 2.71, 95% CI 2.23-3.19). In the BKMR analysis, the effect of PFAS mixture on serum lipids increased significantly when their concentrations were at their 75th percentiles or above, compared to those at their 50th percentile. All methods revealed a major contribution of PFOS and PFNA, although the main exposure was due to PFOA. We found suggestive evidence that associations varied when stratified by gender. CONCLUSIONS: The PFAS mixture was positively associated with lipid parameters, regardless of the applied method. Very similar results obtained from the three methods may be attributed to the linear positive association with the outcomes and no interaction between each PFAS.

Perfluoroalkyl substance mixtures and cardio-metabolic outcomes in highly exposed male workers in the Veneto Region: A mixture-based approach.

BACKGROUND: Perfluoroalkyl substances (PFAS) have been consistently associated with cardio-metabolic traits. Occupational exposures to multiple PFAS with health outcomes have been poorly investigated. The aim of the present study was to examine these associations among former workers involved in PFAS production. METHODS: We considered 232 male ex-employees who had worked in a factory (Trissino, Veneto Region, Italy), which produced PFAS and other chemicals during 1968-2018. Out of twelve serum PFAS, only four (PFOA, PFOS, PFHxS, and PFNA) were quantifiable in at least 50% of samples. Non-fasting serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured. The associations between serum PFAS mixture and considered outcomes were assessed through linear regression mixed models and Weighted Quantile Sum (WQS) regression, adjusting for potential confounders. RESULTS: PFOA was detected at the highest level, with a median concentration (in ng/mL) of 80.8 (min-max: 0.35-13,033), followed by PFOS (median: 8.55, min-max: 0.35-343), PFHxS (median: 6.8, min-max: 0.35-597) and PFNA (median: 0.8, min-max: 0.35-5). We observed that each A quartile increase in the WQS index was positively associated with the levels of TC (ß: 8.41, 95% IC: 0.78-16.0), LDL-C (ß: 8.02, 95% IC: 1-15.0) and SBP (ß: 3.21, 95% IC: 0.82-5.60). No association of serum PFAS concentration on HDL cholesterol and DBP emerged. WQS analyses revealed a major contribution of PFNA and PFHxS for the cholesterol levels, although PFOA reported the highest concentration. PFOA and PFOS emerged as chemicals of concern regarding the association with SBP. CONCLUSIONS: The results showed a clear association between serum PFAS levels and markers of cardiovascular risk and support the importance of clinical surveillance of cardiovascular risk factors in population with a high exposure to PFAS, especially in the occupational setting.

How to investigate human health effects related to exposure to mixtures of per- and polyfluoroalkyl substances: A systematic review of statistical methods.

BACKGROUND: Humans are exposed to several per- and polyfluoroalkyl substances (PFAS) daily; however, most previous studies have focused on individual PFAS. Although attention to effects of exposure to mixtures of PFAS has grown in recent years, there is no consensus on the appropriate statistical methods that can be used to assess their combined effect on human health. OBJECTIVES: We aim to perform a comprehensive review of the statistical methods used in the existing studies which evaluate the association between exposure to mixtures of PFAS and any adverse human health effect. METHODS: The online databases PubMed, Embase and Scopus were searched for eligible studies, published during the last ten years (last search performed on April 08, 2021). Covidence software was used by two different reviewers to perform a title/abstract screening, followed by a full text revision of the selected papers. RESULTS: A total of 3640 papers were identified, and after the screening process, 53 papers were included in the current review. Most of the studies were published between 2019 and 2021 and were conducted mainly in North America and Europe; more than half of the studies (28 out of 53) were conducted on mother and child pairs. WQS (Weighted Quantile Sum) Regression and BKMR (Bayesian Kernel Machine Regression) were used in 36 out of 53 papers to model mixtures' effects. Health outcomes included in the studies are immunotoxicity (n = 8), fetal development (n = 7), neurodevelopment (n = 9), reproductive hormones (n = 6), thyroid hormones (n = 7), outcomes related to metabolic pathways (n = 16). CONCLUSION: Studies on human exposure to PFAS as complex mixtures and health consequences have substantially increased in the last few years. Based on our findings, we propose that addressing risk from PFAS mixtures will likely require combinations of approaches and implementation of constantly evolving statistical methods. Specific guidelines and tools for quality assessment and publication of mixture observational studies are warranted.

PFAS Concentrations and Cardiometabolic Traits in Highly Exposed Children and Adolescents.

BACKGROUND: Residents of a large area of north-eastern Italy were exposed for decades to high concentrations of perfluoroalkyl and polyfluoroalkyl substances (PFAS) via drinking water. Despite the large amount of evidence in adults of a positive association between serum PFAS and metabolic outcomes, studies focusing on children and adolescents are limited. We evaluated the associations between serum PFAS concentrations that were quantifiable in at least 40% of samples and lipid profile, blood pressure (BP) and body mass index (BMI) in highly exposed adolescents and children. METHODS: A cross-sectional analysis was conducted in 6669 adolescents (14-19 years) and 2693 children (8-11 years) enrolled in the health surveillance program of the Veneto Region. Non-fasting blood samples were obtained and analyzed for perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexanesulfonic acid (PFHxS), perfluorononanoic acid (PFNA), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and triglycerides. Low-density lipoprotein cholesterol (LDL-C) was calculated. Systolic and diastolic BP were measured, and BMI z-score accounting for age and sex was estimated. The associations between ln-transformed PFAS (and categorized into quartiles) and continuous outcomes were assessed using generalized additive models. The weighted quantile sum regression approach was used to assess PFAS-mixture effects for each outcome. Analyses were stratified by gender and adjusted for potential confounders. RESULTS: Among adolescents, significant associations were detected between all investigated PFAS and TC, LDL-C, and to a lesser extent HDL-C. Among children, PFOS and PFNA had significant associations with TC, LDL-C and HDL-C, while PFOA and PFHxS had significant associations with HDL-C only. Higher serum concentrations of PFAS, particularly PFOS, were associated with lower BMI z-score. No statistically significant associations were observed between PFAS concentrations and BP. These results were confirmed by the multi-pollutant analysis. CONCLUSIONS: Our study supports a consistent association between PFAS concentration and serum lipids, stronger for PFOS and PFNA and with a greater magnitude among children compared to adolescents, and a negative association of PFAS with BMI.

Avoidable Hospitalization for Heart Failure Among a Cohort of 18- to 64-Year-Old Italian Citizens and Immigrants: Results From the Italian Network for Longitudinal Metropolitan Studies.

BACKGROUND: Heart failure (HF) represents a severe public health burden. In Europe, differences in hospitalizations for HF have been found between immigrants and native individuals, with inconsistent results. Immigrants face many barriers in their access to health services, and their needs may be poorly met. We aimed to compare the rates of avoidable hospitalization for HF among immigrants and native individuals in Italy. METHODS: All 18- to 64-year-old residents of Turin, Venice, Reggio Emilia, Modena, Bologna, and Rome between January 1, 2001 and December 31, 2013 were included in this multicenter open-cohort study. Immigrants from high migratory pressure countries (divided by area of origin) were compared with Italian citizens. Age-, sex-, and calendar year-adjusted hospitalization rate ratios and the 95% CIs of avoidable hospitalization for HF by citizenship were estimated using negative binomial regression models. The hospitalization rate ratios were summarized using a random effects meta-analysis. Additionally, we tested the contribution of socioeconomic status to these disparities. RESULTS: Of the 4 470 702 subjects included, 15.8% were immigrants from high migratory pressure countries. Overall, immigrants showed a nonsignificant increased risk of avoidable hospitalization for HF (hospitalization rate ratio, 1.26 [95% CI, 0.97-1.68]). Risks were higher for immigrants from Sub-Saharan Africa and for males from Northern Africa and Central-Eastern Europe than for their Italian citizen counterparts. Risks were attenuated adjusting for socioeconomic status, although they remained consistent with nonadjusted results. CONCLUSIONS: Adult immigrants from different geographic macroareas had higher risks of avoidable hospitalization for HF than Italian citizens. Possible explanations might be higher risk factors among immigrants and reduced access to primary health care services.

Retrospective survival analysis in patients with metastatic pancreatic ductal adenocarcinoma with insulin-treated type 2 diabetes mellitus.

INTRODUCTION: The association between pancreatic ductal adenocarcinoma (PDAC) and type 2 diabetes mellitus (DM2) has long been evaluated and the role of antidiabetic medications such as metformin has also been investigated. The objective of this study was to examine the association between insulin use and overall survival (OS) in patients with advanced PDAC and DM2. METHODS: We retrospectively collected data from 164 patients, including an exploratory cohort of 96 patients from Medical Oncology Unit, University Hospital and University of Cagliari, Italy, and a validation cohort of 68 patients from Medical Oncology of Modena University Hospital. Patients had metastatic disease and received a first-line gemcitabine-based chemotherapy and, subsequently, a second-line fluoropyrimidines-based chemotherapy. We performed univariate analysis to evaluate correlation between long-term diabetes and overall survival. Then we performed multivariate analysis, adjusting for sex, metastatic sites, Eastern Cooperative Oncology Group Performance Status, Ca19.9 levels, N/L ratio, and lactate dehydrogenase levels at diagnosis, to confirm the independence of the variable. RESULTS: In the exploratory cohort, DM2 was significantly associated with higher median OS at univariate analysis (16 vs 10 months; p = 0.004). This result was confirmed by validation cohort (11 months vs 6 months; p = 0.01). In multivariate analysis, insulin-treated patients compared with non diabetic patients showed a significantly increased survival of 4.6 months (p = 0.03). CONCLUSIONS: Patients with insulin-treated metastatic PDAC showed better OS than non diabetic patients, as demonstrated by both cohorts. The correlation between OS and insulin-treated DM2 should be investigated further through a prospective clinical trial.