Dioxin exposure associated with fecundability and infertility in mothers and daughters of Seveso, Italy.

STUDY QUESTION: Is there an association between 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure and fecundability and infertility among Seveso women and their daughters? SUMMARY ANSWER: TCDD exposure is associated with a decrease in fecundability and increased risk of infertility in women, as well as their daughters. WHAT IS KNOWN ALREADY: In animal studies, maternal exposure to TCDD is associated with decreased fertility in offspring. Effects of TCDD are mediated by activation of the aryl hydrocarbon receptor (AHR) pathway. STUDY DESIGN, SIZE, DURATION: The Seveso Women's Health Study (SWHS) has followed 981 women exposed to TCDD in a 1976 accident since 1996. In 2014, we initiated the Seveso Second Generation Study to follow-up their children. PARTICIPANTS/MATERIALS, SETTING, METHODS: We obtained information on pregnancy history including time of trying to conceive from SWHS women and their daughters who were 18 years or older. We considered TCDD exposure as initial 1976 serum TCDD concentration and estimated TCDD at pregnancy. We examined relationships of TCDD exposure with time to pregnancy (TTP, the monthly probability of conception within the first 12 months of trying) and infertility (≥12 months of trying to conceive). We also assessed contributions of polymorphisms in the AHR pathway via genetic risk score. MAIN RESULTS AND THE ROLE OF CHANCE: Among SWHS women (n = 446), median TTP was 3 months and 18% reported taking ≥12 months to conceive. Initial 1976 TCDD (log10) was associated with longer TTP (adjusted fecundability odds ratio = 0.82; 95% CI 0.68-0.98) and increased risk of infertility (adjusted relative risk = 1.35; 95% CI 1.01-1.79). TCDD at pregnancy yielded similar associations. Among SWHS daughters (n = 66), median TTP was 2 months and 11% reported taking ≥12 months to conceive. Daughters showed similar, but non-significant, associations with maternal TCDD exposure. LIMITATIONS, REASONS FOR CAUTION: A limitation of this study is time to pregnancy was reported retrospectively, although previous studies have found women are able to recall time to conception with a high degree of accuracy many years after the fact. The number of SWHS daughters who had a live birth was small and we were unable to examine fecundability of SWHS sons. WIDER IMPLICATIONS OF THE FINDINGS: Consistent with previous findings in animal studies, our study found that TCDD exposure may be associated with decreased fertility in Seveso mothers and potentially in their daughters exposed in utero. There may be susceptible genetic subgroups. The literature has largely considered the genetics of the AHR pathway in the context of male fertility but not female fertility, despite strong biological plausibility. These findings should be replicated in larger populations and of different ancestry. Future studies in Seveso should examine the sons and the grandchildren of exposed mothers given the animal literature suggesting potential heritable epigenetic effects. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by grant numbers F06 TW02075-01 from the National Institutes of Health, R01 ES07171 and 2P30-ESO01896-17 from the National Institute of Environmental Health Sciences, R82471 from the U.S. Environmental Protection Agency and #2896 from Regione Lombardia and Fondazione Lombardia Ambiente, Milan, Italy. J.A. was supported by F31ES026488 from the National Institutes of Health. The authors declare they have no actual or potential competing financial interests. TRIAL REGISTRATION NUMBER: N/A.

Age at menarche in Seveso daughters exposed in utero to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

In utero exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is associated with delayed pubertal development in animal studies. No epidemiologic study has investigated this association. We examined the relationship of in utero exposure to TCDD with reported age at onset of menarche in female children born to a unique cohort of TCDD-exposed women resulting from an explosion in Seveso, Italy, on 10 July 1976. METHODS: In 2014, nearly 40 years after the explosion, we enrolled postexplosion offspring, 2 to 39 years of age, in the Seveso Second Generation Study. Age at onset of menarche (years) was collected for 316 daughters by maternal report or self-report at interview. In utero TCDD exposure was defined by maternal TCDD serum concentrations extrapolated to the pregnancy. RESULTS: At interview, 287 daughters were postmenarche and reported age at menarche averaged 12.1 years (±1.3 years). Overall, we found no change in risk of menarche onset with a 10-fold increase in in utero TCDD exposure (hazard ratio [HR] = 0.86; 95% confidence interval [CI] = 0.71, 1.04). When we considered maternal menarche status in 1976 as a potentially sensitive developmental exposure window, in utero TCDD (log10) was associated with later age at menarche among daughters whose mothers were premenarche (HR = 0.71; 95% CI = 0.52, 0.97) but not postmenarche (HR = 0.89; 95% CI = 0.71, 1.12) at the time of the explosion (P int = 0.24). CONCLUSIONS: These results suggest that in utero TCDD exposure may alter pubertal timing among daughters of women who were prepubescent at the time of the Seveso accident.

Prenatal dioxin exposure and thyroid hormone levels in the Seveso second generation study.

BACKGROUND: In animal studies, perinatal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) alters thyroid homoeostasis and thyroid hormone concentrations; epidemiologic evidence is limited. OBJECTIVES: We aimed to determine the association of prenatal exposure to TCDD with thyroid hormone concentrations in the Seveso Second Generation Study, a unique cohort of children born to TCDD-exposed women resulting from a 1976 chemical factory explosion in Seveso, Italy. METHODS: We included 570 children (288 female, 282 male) with complete follow-up data, including a fasting blood draw. Serum levels of total and free thyroxine (T4), free triiodothyronine (T3), and thyroid stimulating hormone (TSH) were measured using immunoassays. We defined prenatal TCDD exposure as: 1) maternal initial TCDD concentration measured in serum collected soon after the explosion and 2) maternal TCDD estimated at pregnancy. RESULTS: Compared to the lowest quartile (Q1), maternal initial serum TCDD was associated with lower free T3 (Q2: adj-ß = -0.13, 95%CI -0.26, 0.00; Q3: adj-ß = -0.22, 95%CI -0.35, -0.09; Q4: adj-ß = -0.14, 95%CI -0.28, 0.00; p-trend = 0.02). In participants with high thyroid antibody status, inverse associations between maternal initial serum TCDD and free T3 were significantly stronger than in participants with normal antibody status (p-interaction = 0.02). We also observed a positive association between maternal initial serum TCDD and TSH concentrations in participants with high thyroid antibody status (Q2: adj-ß = 11.4%, 95%CI -25.2, 66.1; Q3: adj-ß = 49.0%, 95%CI 3.0, 115.5; Q4: adj-ß = 105.5, 95%CI 36.6, 209.2; p-trend < 0.01) but not in those participants with normal antibody status (p-interaction < 0.01). Similar results were found for TCDD estimated at pregnancy. DISCUSSION: Our results suggest prenatal exposure to TCDD, a potent endocrine-disrupting compound, may alter thyroid function later in life. Populations with additional thyroid stress may be particularly susceptible to in utero exposure of thyroid disrupting chemicals.

Prenatal dioxin exposure and glucose metabolism in the Seveso Second Generation study.

BACKGROUND: Exposure to endocrine disrupting compounds such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during susceptible developmental windows may alter risk of metabolic disease later in life. Animal studies of in utero and lactational TCDD exposure report associations with alterations in insulin sensitivity and energy homeostasis, but epidemiologic evidence is limited. We examined the relationship of prenatal TCDD exposure with markers of glucose homeostasis in the Seveso Second Generation study, a unique cohort of children born to TCDD-exposed women resulting from a 1976 explosion in Seveso, Italy. METHODS: We included 426 children who were 18 years or older with complete follow-up data including a fasting blood draw. Insulin and glucose were measured and the updated homoeostatic model assessment was used to estimate insulin resistance (HOMA2-IR) and beta-cell function (HOMA2-B). Prenatal TCDD exposure was defined in two ways, as initial maternal serum TCDD concentration and TCDD estimated at pregnancy. RESULTS: The children (222 female, 204 male) averaged 28.6 (±6.0) years. We found a 10-fold increase in TCDD estimated at pregnancy was inversely associated with insulin (adj-ß = -1.24 µIU/mL, 95% confidence interval (CI): -2.38, -0.09) and HOMA2-B (adj-ß = -10.2% decrease, 95% CI: -17.8, -1.9) among daughters, but not sons (insulin: adj-ß = 0.57 µIU/mL, 95% CI: -0.84, 1.98, P for interaction = 0.04; and HOMA2-B: adj-ß = 0.8% increase, 95% CI -10.7, 13.9, P for interaction = 0.11). Similar effect modification was observed for TCDD estimated at pregnancy and HOMA2-IR (P for interaction = 0.13). The models for initial maternal serum TCDD showed similar effect modification by child sex. The observed associations in daughters showed evidence of mediation by body mass index, which we have previously found to be associated with prenatal TCDD exposure in female offspring. CONCLUSION: These results suggest prenatal exposure to TCDD is associated with lower insulin resistance and beta compensation in female offspring, and show evidence of mediation by body mass index.

Cardiovascular Effects of Pioglitazone or Sulfonylureas According to Pretreatment Risk: Moving Toward Personalized Care.

CONTEXT: Hypoglycemic drugs with proven cardiovascular (CV) benefits are recommended for patients with type 2 diabetes and CV disease. Whether the beneficial effects extend to those at lower risk remains unclear. AIM: We investigated the long-term CV effects of pioglitazone or sulfonylureas (SUs) across the spectrum of pretreatment CV risk. METHODS: Among 2820 participants of the TOSCA.IT trial, four subgroups with different risk of outcome-a composite of all-cause death, nonfatal myocardial infarction, nonfatal stroke, urgent coronary revascularization-were identified by the RECursive Partitioning and AMalgamation (RECPAM) method. Within each group, the effect of SUs or pioglitazone on the outcome was evaluated. RESULTS: Sex was the first splitting variable, followed by urinary albumin-to-creatinine ratio (UACR) (>9 mg/g or ≤9 mg/g) and body mass index (BMI) (>28.7 or ≤28.7 kg/m2). Female patients had the lowest risk (reference); male patients with UACR >9 mg/g and BMI >28.7 kg/m2 had the highest risk [hazard ratio (HR), 5.58; 95% CI, 3.32 to 9.69]. Patients in this group present a cluster of conditions suggestive of marked insulin resistance (higher BMI, waist circumference, triglycerides, blood pressure, and UACR and lower high-density lipoprotein cholesterol) than the other groups. Treatment with pioglitazone in this group was associated with a significantly lower occurrence of the outcome than SUs (HR, 0.48; 95% CI, 0.25 to 0.76). No significant difference between study treatments was observed in the other RECPAM classes. CONCLUSIONS: It is possible to identify patients with type 2 diabetes early in the stage of their disease and who are largely free from evident CV disease in whom add-on pioglitazone to metformin confers CV protection as compared with SUs.

The 2nd to 4th digit length ratio (2D:4D) among children of Seveso women exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

BACKGROUND: Exposure to endocrine-disrupting chemicals (EDCs) during sensitive developmental windows, such as in utero, may influence disease later in life but direct measurement of fetal hormones is not feasible. The ratio of the length of the second finger digit to the fourth digit (2D:4D), a sexually dimorphic trait, is a biomarker of androgen levels and the androgen/estrogen balance in utero. However, it is unclear whether in utero EDC exposure might alter 2D:4D ratio. AIMS: We examined 2D:4D ratio in Seveso children in relation to in utero exposure to a potent EDC, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) using linear regression. STUDY DESIGN: The Seveso Women's Health Study (SWHS) is a historical cohort study, following the health of women exposed to TCDD during a 1976 explosion in Seveso, Italy. Individual-level TCDD was measured for SWHS in serum collected soon after the accident. In 2014, the SWHS children born after the explosion were enrolled in the Seveso Second Generation Study. SUBJECTS: 594 SWHS children born post-explosion to 397 mothers. OUTCOME MEASURES: Right hand 2D:4D ratio. RESULTS: On average, 2D:4D ratio for males was significantly lower than for females (p < 0.05). Overall, in utero TCDD exposure, either as maternal initial serum TCDD concentration or as TCDD extrapolated to pregnancy was not significantly associated with 2D:4D ratio in Seveso children. Results from all adjusted sensitivity analyses remained non-significant. CONCLUSIONS: Our results suggest in utero exposure to TCDD is not associated with alteration in 2D:4D ratio.

Prenatal dioxin exposure and neuropsychological functioning in the Seveso Second Generation Health Study.

BACKGROUND: Prenatal 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure has been shown to alter sexual differentiation of the brain in animal models, impacting pubertal development, behavior, cortical dominance, and cognition. The effects of early life exposure to dioxin-like compounds on human neurodevelopment, however, are less clear and warrant further investigation. METHODS: The Seveso Women's Health Study (SWHS), initiated in 1996, is a well-characterized cohort of 981 Italian women who lived in proximity to an industrial accident in July 1976 that resulted in one of the highest residential TCDD exposures on record. In 2014-2016, we enrolled offspring born after the accident into the Seveso Second Generation Health Study. Children aged 7-17 years old (n = 161) completed a neuropsychological assessment spanning executive function and reverse learning (Wisconsin Card Sort), non-verbal intelligence (Raven's Progressive Matrices), attention and hyperactivity (Connor's Continuous Performance (CPT), and memory (Rey's Auditory Verbal Learning). We used multivariate regression with robust standard error estimates accounting for clustering of siblings to model the associations between these outcomes and prenatal exposure defined as TCDD measured in maternal serum collected soon after the explosion and estimated to pregnancy. RESULTS: The children (82 male, 79 female) averaged 13.1 (±2.9) years of age. Adjusting for covariates, a 10-fold increase in maternal serum TCDD was not adversely associated with reverse learning/set-shifting, memory, attention/impulsivity, or non-verbal intelligence. In sex-stratified models, prenatal TCDD was associated with more non-perseverative errors in boys but not in girls (pint = 0.04). TCDD was also associated with attention deficits on the CPT but only among children with the shortest breastfeeding histories. CONCLUSIONS: While overall, there were no significant associations, the observed differential neurotoxic sensitivities to TCDD by sex and lactation history may warrant confirmation in future studies.

In utero dioxin exposure and cardiometabolic risk in the Seveso Second Generation Study.

BACKGROUND/OBJECTIVES: In utero exposure to endocrine-disrupting compounds such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) may alter risk of obesity and related metabolic disease later in life. We examined the relationship of prenatal exposure to TCDD with obesity and metabolic syndrome (MetS) in children born to a unique cohort of TCDD-exposed women resulting from a 1976 explosion in Seveso, Italy. SUBJECTS/METHODS: In 2014, nearly 40 years after the explosion, we enrolled 611 post-explosion offspring, 2 to 39 years of age, in the Seveso Second Generation Study. In utero TCDD exposure was defined primarily as TCDD concentration measured in maternal serum collected soon after the explosion and alternately as TCDD estimated at pregnancy. We measured height, weight, waist circumference, body fat, blood pressure, and fasting blood levels of lipids and glucose, which were combined to assess body mass index (BMI) and MetS. RESULTS: Children (314 female, 297 male) averaged 23.6 (±6.0) years of age. Among the 431 children ≥18 years, a 10-fold increase in initial maternal TCDD concentration was inversely associated with BMI in daughters (adj-ß = -0.99 kg/m2; 95% CI -1.86, -0.12), but not sons (adj-ß = 0.41 kg/m2; 95% CI -0.35, 1.18) (p-int = 0.02). A similar relationship was found in the younger children (2-17 years); a 10-fold increase in initial maternal TCDD was inversely associated with BMI z-score (adj-ß = -0.59 kg/m2; 95% CI -1.12, -0.06) among daughters, but not sons (adj-ß = 0.04 kg/m2; 95% CI -0.34, 0.41) (p-int = 0.03). In contrast, in sons only, initial maternal TCDD was associated with increased risk for MetS (adj-RR = 2.09, 95% CI 1.09, 4.02). Results for TCDD estimated at pregnancy were comparable. CONCLUSIONS: These results suggest prenatal TCDD exposure alters cardiometabolic endpoints in a sex-specific manner. In daughters, in utero TCDD is inversely associated with adiposity measures. In sons, in utero TCDD is associated with increased risk for MetS.

The Seveso accident: A look at 40 years of health research and beyond.

A 1976 chemical factory explosion near Seveso, Italy exposed residents to high levels of 2,3,7,8-tetracholorodibenzo-p-dioxin (TCDD or dioxin). Dioxin is a known human carcinogen and potent endocrine disruptor. It is highly lipophilic and has a long half-life in humans. Much of what we know and can learn about the risks of dioxin exposure on human health arose from the tragic circumstances of Seveso. This review aims to describe the Seveso accident, summarize the results of 40 years of research on the health of the Seveso population since the accident, and discuss next-stage research on the health of Seveso residents, their children, and grandchildren.

AHR gene-dioxin interactions and birthweight in the Seveso Second Generation Health Study.

Background: 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) is proposed to interfere with fetal growth via altered activity of the aryl hydrocarbon receptor (protein: AHR; gene: AHR) pathway which regulates diverse biological and developmental processes including xenobiotic metabolism. Genetic variation in AHR is an important driver of susceptibility to low birthweight in children exposed to prenatal smoking, but less is known about these genetic interactions with TCDD, AHR's most potent xenobiotic ligand. Methods: The Seveso Women's Health Study (SWHS), initiated in 1996, is a cohort of 981 Italian women exposed to TCDD from an industrial explosion in July 1976. We measured TCDD concentrations in maternal serum collected close to the time of the accident. In 2008 and 2014, we followed up the SWHS cohort and collected data on birth outcomes of SWHS women with post-accident pregnancies. We genotyped 19 single nucleotide polymorphisms (SNPs) in AHR among the 574 SWHS mothers. Results: Among 901 singleton births, neither SNPs nor TCDD exposure alone were significantly associated with birthweight. However, we found six individual SNPs in AHR which adversely modified the association between maternal TCDD and birthweight, implicating gene-environment interaction. We saw an even stronger susceptibility to TCDD due to interaction when we examined the joint contribution of these SNPs in a risk allele score. These SNPs were all located in noncoding regions of AHR, particularly in proximity to the promoter. Conclusions: This is the first study to demonstrate that genetic variation across the maternal AHR gene may shape fetal susceptibilities to TCDD exposure.

Prenatal exposure to TCDD and atopic conditions in the Seveso second generation: a prospective cohort study.

BACKGROUND: 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a toxic environmental contaminant that can bioaccumulate in humans, cross the placenta, and cause immunological effects in children, including altering their risk of developing allergies. On July 10, 1976, a chemical explosion in Seveso, Italy, exposed nearby residents to a high amount of TCDD. In 1996, the Seveso Women's Health Study (SWHS) was established to study the effects of TCDD on women's health. Using data from the Seveso Second Generation Health Study, we aim to examine the effect of prenatal exposure to TCDD on the risk of atopic conditions in SWHS children born after the explosion. METHODS: Individual-level TCDD was measured in maternal serum collected soon after the accident. In 2014, we initiated the Seveso Second Generation Health Study to follow-up the children of the SWHS cohort who were born after the explosion or who were exposed in utero to TCDD. We enrolled 677 children, and cases of atopic conditions, including eczema, asthma, and hay fever, were identified by self-report during personal interviews with the mothers and children. Log-binomial and Poisson regressions were used to determine the association between prenatal TCDD and atopic conditions. RESULTS: A 10-fold increase in 1976 maternal serum TCDD (log10TCDD) was not significantly associated with asthma (adjusted relative risk (RR) = 0.93; 95% CI: 0.61, 1.40) or hay fever (adjusted RR = 0.99; 95% CI: 0.76, 1.27), but was significantly inversely associated with eczema (adjusted RR = 0.63; 95% CI: 0.40, 0.99). Maternal TCDD estimated at pregnancy was not significantly associated with eczema, asthma, or hay fever. There was no strong evidence of effect modification by child sex. CONCLUSIONS: Our results suggest that maternal serum TCDD near the time of explosion is associated with lower risk of eczema, which supports other evidence pointing to the dysregulated immune effects of TCDD.

Neurocognitive and physical functioning in the Seveso Women's Health Study.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is neurotoxic in animals but few studies have investigated its effects on the human brain. Related dioxin-like compounds have been linked to poorer cognitive and motor function in older adults, with effects more pronounced in women, perhaps due to the loss of neuro-protective estrogen in menopause. On 10 July 1976, a chemical explosion in Seveso, Italy, resulted in one of the highest known residential exposures to TCDD. In 1996, we initiated the Seveso Women's Health Study, a retrospective cohort study of the health of the women who were newborn to 40 years old in 1976. Here, we investigate whether TCDD exposure is associated with physical functioning and working memory more than 20 years later. Individual TCDD concentration (ppt) was measured in archived serum collected soon after the explosion. In 1996 and 2008, we measured physical functioning (n=154) and working memory (n=459), respectively. We examined associations between serum TCDD and motor and cognitive outcomes with multivariate linear regression and semi-parametric estimators. A 10-fold increase in serum TCDD was not associated with walking speed (adjusted ß=0.0006ft/s, 95% Confidence Interval (CI): -0.13, 0.13), upper body mobility (adjusted ß=-0.06, 95% CI: -0.36, 0.23), or manual dexterity (adjusted ß=0.34, 95% CI: -0.65, 1.33). We observed an inverted U-shaped association in grip strength, with poorer strength in the lowest and highest TCDD exposure levels. There was no association between TCDD and the Wechsler digit and spatial span tests. Neither menopause status at assessment nor developmental timing of exposure modified associations between TCDD and working memory. Our findings, in one of the only studies of TCDD's effects on neuropsychological and physical functioning in women, do not indicate an adverse effect on these domains, with the exception of a U-shaped relationship with grip strength. Given the limited assessment and relative youth of the women at this follow-up, future work examining additional neuropsychological outcomes is warranted.

Effects on the incidence of cardiovascular events of the addition of pioglitazone versus sulfonylureas in patients with type 2 diabetes inadequately controlled with metformin (TOSCA.IT): a randomised, multicentre trial.

BACKGROUND: The best treatment option for patients with type 2 diabetes in whom treatment with metformin alone fails to achieve adequate glycaemic control is debated. We aimed to compare the long-term effects of pioglitazone versus sulfonylureas, given in addition to metformin, on cardiovascular events in patients with type 2 diabetes. METHODS: TOSCA.IT was a multicentre, randomised, pragmatic clinical trial, in which patients aged 50-75 years with type 2 diabetes inadequately controlled with metformin monotherapy (2-3 g per day) were recruited from 57 diabetes clinics in Italy. Patients were randomly assigned (1:1), by permuted blocks randomisation (block size 10), stratified by site and previous cardiovascular events, to add-on pioglitazone (15-45 mg) or a sulfonylurea (5-15 mg glibenclamide, 2-6 mg glimepiride, or 30-120 mg gliclazide, in accordance with local practice). The trial was unblinded, but event adjudicators were unaware of treatment assignment. The primary outcome, assessed with a Cox proportional-hazards model, was a composite of first occurrence of all-cause death, non-fatal myocardial infarction, non-fatal stroke, or urgent coronary revascularisation, assessed in the modified intention-to-treat population (all randomly assigned participants with baseline data available and without any protocol violations in relation to inclusion or exclusion criteria). This study is registered with ClinicalTrials.gov, number NCT00700856. FINDINGS: Between Sept 18, 2008, and Jan 15, 2014, 3028 patients were randomly assigned and included in the analyses. 1535 were assigned to pioglitazone and 1493 to sulfonylureas (glibenclamide 24 [2%], glimepiride 723 [48%], gliclazide 745 [50%]). At baseline, 335 (11%) participants had a previous cardiovascular event. The study was stopped early on the basis of a futility analysis after a median follow-up of 57·3 months. The primary outcome occurred in 105 patients (1·5 per 100 person-years) who were given pioglitazone and 108 (1·5 per 100 person-years) who were given sulfonylureas (hazard ratio 0·96, 95% CI 0·74-1·26, p=0·79). Fewer patients had hypoglycaemias in the pioglitazone group than in the sulfonylureas group (148 [10%] vs 508 [34%], p<0·0001). Moderate weight gain (less than 2 kg, on average) occurred in both groups. Rates of heart failure, bladder cancer, and fractures were not significantly different between treatment groups. INTERPRETATION: In this long-term, pragmatic trial, incidence of cardiovascular events was similar with sulfonylureas (mostly glimepiride and gliclazide) and pioglitazone as add-on treatments to metformin. Both of these widely available and affordable treatments are suitable options with respect to efficacy and adverse events, although pioglitazone was associated with fewer hypoglycaemia events. FUNDING: Italian Medicines Agency, Diabete Ricerca, and Italian Diabetes Society.

A comparative assessment of major international disasters: the need for exposure assessment, systematic emergency preparedness, and lifetime health care.

BACKGROUND: The disasters at Seveso, Three Mile Island, Bhopal, Chernobyl, the World Trade Center (WTC) and Fukushima had historic health and economic sequelae for large populations of workers, responders and community members. METHODS: Comparative data from these events were collected to derive indications for future preparedness. Information from the primary sources and a literature review addressed: i) exposure assessment; ii) exposed populations; iii) health surveillance; iv) follow-up and research outputs; v) observed physical and mental health effects; vi) treatment and benefits; and vii) outreach activities. RESULTS: Exposure assessment was conducted in Seveso, Chernobyl and Fukushima, although none benefited from a timely or systematic strategy, yielding immediate and sequential measurements after the disaster. Identification of exposed subjects was overall underestimated. Health surveillance, treatment and follow-up research were implemented in Seveso, Chernobyl, Fukushima, and at the WTC, mostly focusing on the workers and responders, and to a lesser extent on residents. Exposure-related physical and mental health consequences were identified, indicating the need for a long-term health care of the affected populations. Fukushima has generated the largest scientific output so far, followed by the WTCHP and Chernobyl. Benefits programs and active outreach figured prominently in only the WTC Health Program. The analysis of these programs yielded the following lessons: 1) Know who was there; 2) Have public health input to the disaster response; 3) Collect health and needs data rapidly; 4) Take care of the affected; 5) Emergency preparedness; 6) Data driven, needs assessment, advocacy. CONCLUSIONS: Given the long-lasting health consequences of natural and man-made disasters, health surveillance and treatment programs are critical for management of health conditions, and emergency preparedness plans are needed to prevent or minimize the impact of future threats.

Serum dioxin concentrations and thyroid hormone levels in the Seveso Women's Health Study.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a persistent environmental contaminant. Although experimental evidence suggests that TCDD alters thyroid hormone levels in rodents, human data are inconsistent. In 1976, a trichlorophenol plant exploded in Seveso, Italy. Women living in highly exposed areas were followed through the Seveso Women's Health Study. TCDD concentrations were measured in 1976 (n = 981) and 1996 (n = 260), and levels of total thyroxine, free thyroxine, free triiodothyronine, and thyroid-stimulating hormone were measured in 1996 (n = 909) and 2008 (n = 724). We used conditional multiple linear regression and marginal structural models with inverse-probability-of-treatment weights to evaluate associations and causal effects. TCDD concentration in 1976 was inversely associated with total thyroxine level in 1996 but not in 2008. Associations were stronger among women who had been exposed before menarche. Among these women, associations between total thyroxine and concurrent 1996 TCDD were slightly weaker than those with 1976 TCDD. A model including both 1976 and 1996 measurements strengthened the relationship between 1976 TCDD and total thyroxine but drove the association with 1996 TCDD to the null. TCDD exposure was not associated with levels of other thyroid hormones. TCDD exposure, particularly exposure before menarche, may have enduring impacts on women's total thyroxine levels. Initial exposure appears to be more influential than remaining body burden.

Maternal dioxin exposure and pregnancy outcomes over 30 years of follow-up in Seveso.

Animal evidence suggests an association between exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and adverse pregnancy outcomes. Epidemiologic studies report inconsistent results, but are limited by narrow range of exposure, small sample size, and lack of a biologic measure of highest lifetime exposure. On July 10, 1976, a chemical explosion in Seveso, Italy resulted in the highest known residential exposure to TCDD. In 1996, we initiated the Seveso Women's Health Study (SWHS), a retrospective cohort of TCDD exposure and reproductive health. Individual-level TCDD was measured in serum collected soon after the explosion. After 20years of follow-up, we found no association between maternal TCDD in 1976 serum or estimated at pregnancy and spontaneous abortion (SAB), fetal growth, or gestational length. Here, we present an updated analysis of TCDD exposure and adverse pregnancy outcomes from a subsequent follow-up of the SWHS cohort in 2008-2009. SWHS women had 1211 post-explosion pregnancies through the 2008-2009 follow-up. We found no association between TCDD estimated at pregnancy and SAB, fetal growth, or gestational length. However, we found a non-significant inverse association between maternal 1976 serum TCDD and birthweight (adjusted ß=-22.8, 95% CI: -80.1, 34.6). The association was stronger among first post-explosion births, but remained non-significant (adjusted ß=-47.7, 95% CI: -107.3, 11.9). SWHS is the first study to be able to consider two potentially relevant measures of TCDD exposure: highest lifetime dose and in utero. Our results, although non-significant, suggest that highest dose may be more relevant in epidemiologic studies of TCDD and pregnancy outcomes.

Serum TCDD and TEQ concentrations among Seveso women, 20 years after the explosion.

The Seveso Women's Health Study (SWHS) is a historical cohort study of the female population residing near Seveso, Italy, on 10 July 1976, when a chemical explosion resulted in the highest known residential exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Individual TCDD concentration was measured in serum collected near the time of the explosion, and in 1996, we collected adequate blood for TCDD and total dioxin toxic equivalent (TEQ) measurement. Polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls were measured in 1996 serum for a sample (n=225, 23%) of the SWHS cohort and WHO 2005 TEQs were calculated. We examined characteristics that predict 1996 TCDD concentrations and estimated TCDD elimination half-life over the 20-year period since the explosion. Median lipid-adjusted TCDD and total TEQ concentrations in 1996 serum were 7.3 and 26.2 p.p.t., respectively. Initial 1976 TCDD and age at explosion were the strongest predictors of 1996 TCDD. The TCDD elimination half-life was 7.1 years for women older than 10 years in 1976, but was shorter in those who were younger. Twenty years after the explosion, TCDD concentrations in this SWHS sample, the majority of who were children in 1976, remain elevated relative to background. These data add to the limited data available on TCDD elimination half-life in children.

Serum dioxin concentrations and bone density and structure in the Seveso Women's Health Study.

BACKGROUND: 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a widespread environmental contaminant, is a known endocrine disruptor. In animal studies, TCDD exposure impairs bone metabolism and increases fragility. To our knowledge, no epidemiologic studies have examined this association. OBJECTIVES: On 10 July 1976, a chemical explosion in Seveso, Italy, resulted in the highest known residential exposure to TCDD. In 1996, we initiated the Seveso Women's Health Study, a retrospective cohort study of the health of the women. In 2008, we followed up the cohort. Here, we evaluated the association between TCDD exposure and bone structure and geometry in adulthood, and considered whether timing of TCDD exposure before achievement of peak bone mass (assumed to occur 2 years after onset of menarche) modified the association. METHODS: Individual TCDD concentration was measured in archived serum collected soon after the explosion. In 2008, 350 women who were <20 years old in 1976 underwent a dual-energy X-ray absorptiometry (DXA) bone scan. Bone mineral density was measured at the lumbar spine and hip, and hip geometry was extracted from hip DXA scans using the hip structural analysis method. RESULTS: Among premenopausal women, TCDD serum levels were associated with some indexes indicating better bone structure in women exposed before peak bone mass (n=219), with stronger associations in those exposed before 5 years of age (n=46). In contrast, among postmenopausal women, TCDD levels were associated with evidence of better bone structure in women exposed after peak bone mass (n=48) than in other women (n=18). CONCLUSIONS: Our current results do not support the hypothesis that postnatal TCDD exposure adversely affects adult bone health. Continued follow-up of women who were youngest at exposure is warranted. Future studies should also focus on those exposed in utero.

Diabetes, metabolic syndrome, and obesity in relation to serum dioxin concentrations: the Seveso women's health study.

BACKGROUND: In animal studies, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) alters glucose transport and increases serum lipid levels and blood pressure. Epidemiologic evidence suggests an association between TCDD and metabolic disease. OBJECTIVES: On 10 July 1976, a chemical explosion in Seveso, Italy, resulted in the highest known residential exposure to TCDD. Using data from the Seveso Women's Health Study (SWHS), a cohort study of the health of the women, we examined the relation of serum TCDD to diabetes, metabolic syndrome, and obesity > 30 years later. METHODS: In 1996, we enrolled 981 women who were newborn to 40 years of age in 1976 and resided in the most contaminated areas. Individual TCDD concentration was measured in archived serum that had been collected soon after the explosion. In 2008, 833 women participated in a follow-up study. Diabetes was classified based on self-report or fasting serum glucose and glycated hemoglobin levels. Metabolic syndrome was defined by International Diabetes Federation criteria. Obesity was defined as body mass index ≥ 30 kg/m2. RESULTS: A 10-fold increase in serum TCDD (log10TCDD) was not associated with diabetes (adjusted hazard ratio = 0.76; 95% CI: 0.45, 1.28) or obesity [adjusted odds ratio (OR) = 0.80; 95% CI: 0.58, 1.10]. Log10TCDD was associated with metabolic syndrome, but only among women who were ≤ 12 years of age at the time of the explosion (adjusted OR = 2.03; 95% CI: 1.25, 3.29; pinteraction = 0.01). CONCLUSIONS: We found an increased prevalence of metabolic syndrome associated with TCDD, but only among women who were the youngest at the time of the explosion. Continued follow-up of the SWHS cohort will be informative.