Persistent hematologic and immunologic disturbances in 8-year-old Dutch children associated with perinatal dioxin exposure.

Perinatal exposure to Dutch "background" dioxin levels in 1990 was high, but comparable with that of other industrialized Western European countries. Exposure during the sensitive perinatal period may cause permanent disturbances. Therefore, we assessed the health status and various hematologic and immunologic parameters among our longitudinal cohort. A medical history was taken and venipuncture performed in a longitudinal cohort of 27 healthy 8-year-old children who had documented perinatal dioxin exposure. Linear regression revealed a decrease in allergy in relation to prenatal (p = 0.02) and postnatal (p = 0.03) dioxin exposure. Increases in CD4+ T-helper cells (p = 0.006) and in CD45RA+ cells (p = 0.02) were seen in relation to postnatal exposure. A persistently decreased platelet count (p = 0.04) and increased thrombopoietin concentration (p = 0.03) were seen in relation to postnatal exposure. This follow-up has shown a decrease in allergy, persistently decreased thrombocytes, increased thrombopoietin, and increased CD4+ T-helper and increased CD45RA+ cell counts. This study provides indications of effects at the stem cell level of perinatal dioxin exposure, persisting until minimally 8 years after birth

Thyroid hormone metabolism and environmental chemical exposure

<p>Abstract</p> <p>Background</p> <p>Polychlorinated dioxins and –furans (PCDD/Fs) and polychlorinated-biphenyls (PCBs) are environmental toxicants that have been proven to influence thyroid metabolism both in animal studies and in human beings. In recent years polybrominated diphenyl ethers (PBDEs) also have been found to have a negative influence on thyroid hormone metabolism. The lower brominated flame retardants are now banned in the EU, however higher brominated decabromo-diphenyl ether (DBDE) and the brominated flame retardant hexabromocyclododecane (HBCD) are not yet banned. They too can negatively influence thyroid hormone metabolism. An additional brominated flame retardant that is still in use is tetrabromobisphenol-A (TBBPA), which has also been shown to influence thyroid hormone metabolism.</p> <p>Influences of brominated flame retardants, PCDD/F’s and dioxin like-PCBs (dl-PCB’s) on thyroid hormone metabolism in adolescence in the Netherlands will be presented in this study and determined if there are reasons for concern to human health for these toxins. In the period 1987-1991, a cohort of mother-baby pairs was formed in order to detect abnormalities in relation to dioxin levels in the perinatal period. The study demonstrated that PCDD/Fs were found around the time of birth, suggesting a modulation of the setpoint of thyroid hormone metabolism with a higher 3,3’, 5,5’tetrathyroxine (T4) levels and an increased thyroid stimulating hormone (TSH). While the same serum thyroid hormone tests (- TSH and T4) were again normal by 2 years of age and were still normal at 8-12 years, adolescence is a period with extra stress on thyroid hormone metabolism. Therefore we measured serum levels of TSH, T4, 3,3’,5- triiodothyronine (T3), free T4 (FT4), antibodies and thyroxine-binding globulin (TBG) in our adolescent cohort.</p> <p>Methods</p> <p>Vena puncture was performed to obtain samples for the measurement of thyroid hormone metabolism related parameters and the current serum dioxin (PCDD/Fs), PCB and PBDE levels.</p> <p>Results</p> <p>The current levels of T3 were positively correlated to BDE-99. A positive trend with FT4 and BDE-99 was also seen, while a positive correlation with T3 and dl-PCB was also seen. No correlation with TBG was seen for any of the contaminants. Neither the prenatal nor the current PCDD/F levels showed a relationship with the thyroid parameters in this relatively small group.</p> <p>Conclusion</p> <p>Once again the thyroid hormone metabolism (an increase in T3) seems to have been influenced by current background levels of common environmental contaminants: dl-PCBs and BDE-99. T3 is a product of target organs and abnormalities might indicate effects on hormone transporters and could cause pathology. While the influence on T3 levels may have been compensated, because the adolescents functioned normal at the time of the study period, it is questionable if this compensation is enough for all organs depending on thyroid hormones.</p

Findings on prenatal, lactational and later childhood exposure to dioxins and dioxin-like compounds: a review of the Amsterdam-Zaandam cohort 1987–2005

The Amsterdam-Zaandam cohort has been studied intermittently since 1987. The cohort was selected for optimal pregnancy and birth, in whom prenatal, lactational and more recently current dioxin exposures were measured. In the perinatal period and during the years thereafter, effects on various organ systems have been documented: thyroid, metabolism, immunity, haematology, motor development, brain development, lung function and puberty. We present a review of the endpoints studied, from the perinatal period into adolescence

Exposure to environmental contaminants and lung function in adolescents—Is there a link?

Dioxins (polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDF)), polychlorinated biphenyls (PCBs), and brominated flame retardants (BDEs) are well known toxic environmental contaminants. Their possible role in the incidence of respiratory disease is not yet well understood. Previous studies showed a negative effect on lung function in relation to prenatal and lactational dioxin exposure in pre-pubertal children. Effects of BDE exposure on the lung function have not previously been evaluated. As part of a longitudinal cohort study, the effects of perinatal dioxin (PCDD/F) exposure and serum PCDD/F, dl-PCB, and BDE levels on lung function in adolescents were assessed using spirometry, a body box, and diffusion measurements. Thirty-three children (born between 1986 and 1991) consented to the current follow-up study. Prenatal, lactational, and current dioxin, PCB, and BDE concentrations were determined using GC-MS. No relationship was seen between prenatal and lactational dioxin exposure, nor with current PCB body burden, and lung function. Indications of increasing airway obstruction were seen in relation to increasing current BDE exposure. This is a novel finding and certainly warrants further research

Alterations in the programming of energy metabolism in adolescents with background exposure to dioxins, dl-PCBs and PBDEs

Dioxins and PCBs are highly toxic and persistent environmental pollutants that are measurable in humans worldwide. These persistent organic pollutants are associated with a higher incidence of diabetes mellitus. We hypothesise that perinatal (background) exposure to industrial pollutants like dioxins also influences body mass development and energy metabolism in later life. In The Netherlands, the perinatal exposure (prenatal exposure and postnatal lactational intake) to dioxins has been studied prospectively since 1987. Fasting glucose, insulin, HbA1c and leptin were analysed in 33 children of the original cohort of 60. BMI, glucose:insulin and BMI:leptin ratios were calculated. Prenatal exposure, lactational intake and current serum levels of dioxins (PCDD/F), dl-PCBs and PBDE concentrations were determined using (HR)GC-MS. Prenatal dioxin (PCDD/F) exposure was positively correlated to the glucose:insulin ratio (p = 0.024) and negatively correlated to the fasting insulin concentration (p = 0.017) in adolescence. Postnatal lactational PCDD/F intake was also negatively correlated to fasting insulin concentration (p = 0.028). Current serum levels of PCDD/Fs and total TEQ (dl-PCBs+PCDD/Fs) were positively correlated to the fasting serum glucose concentration (p = 0.015 and p = 0.037, respectively).No metabolic effects were seen in association with current serum levels of PBDEs. A positive correlation between the insulin and leptin concentrations (p = 0.034) was observed. No effects were found on leptin levels, BMI:leptin ratio, HbA1c levels or BMI. This study indicates that prenatal and lactational exposure influences glucose metabolism in adolescents, presumably through a negative effect on insulin secretion by pancreatic beta cells. Additionally, the very low recent background exposure to dioxins in puberty possibly has an effect on the glucose leve

Current treatment practice of functional abdominal pain disorders in children: A multicenter survey

Background: Approximately 90% of the children with chronic abdominal pain are diagnosed as having functional abdominal pain disorder (FAPD). The Dutch guideline “functional abdominal pain” provides a stepwise approach to treat FAPD. The aim of this survey was twofold first, to determine adherence to the Dutch guideline, and second to determine current management of FAPDs in clinical practice. Methods: A multicenter survey was designed. The survey was sent to pediatricians and pediatric residents in December 2020. The study ran from October 2020 until March 2021. Participants in ten hospitals in the western region of The Netherlands were invited to complete this survey. Respondents who indicated not to treat children with FAPDs or respondents who completed less than 3 steps of the survey were excluded. Results: In total, 85/174 (48.9%) respondents completed the survey. We included 80 respondents, 68 pediatricians and 12 pediatric residents, for analysis. Overall, self-reported guideline adherence was 85%. Self-reported adherence was higher than actual adherence. Only 50% of all respondents followed the first three steps of the guideline. The reported non-pharmacological and pharmacological treatments were diverse and varied between different age groups. The average follow-up duration was between 2 and 6 months, and the most regularly used outcome measures were attendance at school, quality of life, and adequate pain relief/reassurance. Conclusion: We reportedly observed a large variation in the management of children with FAPDs, due to low guideline adherence among clinicians. Improved guideline adherence may be accomplished by updating the guideline with specific recommendations per subtype, follow-up and outcome measures as well measures to improve guideline implementation

Multi-centre study found that strict adherence to guidelines led to computed tomography scans being overused in children with minor head injuries

Aim: Our primary aim was to calculate the head computed tomography (CT) scan rate in children with a minor head injury (MHI) when the Dutch National guidelines were followed in clinical practice. The secondary aim was to determine the incidence of CT abnormalities and the guideline predictors associated with traumatic abnormalities. Methods: We performed a multi-centre, prospective observational cross-sectional study in the emergency departments of six hospitals in The Netherlands between 1 April 2015 and 31 December 2016. Results: Data on 1002 patients were studied and 69% of cases complied with the guidelines. The overall CT rate was 44% and the incidence of traumatic abnormal CT findings was 13%. CT scans were performed in 19% of children under two years of age, 48% of children between two and five years and 63% of children aged six years or more. Multivariate regression analysis for all age categories showed that CT abnormalities were predicted by a Glasgow Coma Scale of less than 15, suspicion of a basal skull fracture, vomiting and scalp haematomas or external lesions of the skull. Conclusion: Strict adherence to the Dutch national guidelines resulted in CT overuse. New guidelines are needed to safely reduce CT scan indications