INMA: “Exposure to persistent organic pollutants during pregnancy may affect cardiometabolic health in preadolescents”

26/07/2023

Prevalence of childhood obesity has been increasing in the past decade, and today 33% of the European children are considered overweight or obese. Childhood obesity is a major public health concern, since it has been linked to higher risk of adult obesity and poorer cardiometabolic health in later life.

Some persistent organic pollutants (POPs) are suspected to alter hormonal metabolisms and may affect human cardiometabolic health. POPs include organochlorine pesticides (e.g., p,p’-DDT, HCB, β-HCH), as well as industrial chemical (PCB). The production and use of these chemicals have been banned under the Stockholm Convention decades ago. However, due to their high persistence in the environment, they are still detected in human bodies, including pregnant women and children. Populations are mostly exposed by contaminated food. During pregnancy, maternal levels of POPs are transmitted to the child through the placenta, and postnatally, via breast milk.

In previous studies, prenatal exposure to POPs has been associated with a risk of elevated body mass index (BMI) and elevated blood pression in childhood. Nevertheless, few studies have investigated whether these associations persist into preadolescence. Also, previous literature has mostly assessed single POPs exposures and did not consider POPs exposure as a mixture.

The main objective of the study was to determine whether prenatal exposure to POPs could affect cardiometabolic health in preadolescents, using adiposity markers and blood pressure data from two birth cohorts in Europe.

A total of 1667 children from the INMA-Gipuzkoa, -Sabadell, -Valencia study (Spain) and the PELAGIE cohort (France) were included. POPs levels were assessed in maternal serum collected at 12 weeks of gestation and in umbilical cord serum, for the INMA study and the PELAGIE cohort, respectively. When children reached 11-13 years, clinical examinations were carried out to measure BMI, percentage of fat mass, abdominal obesity, overweight/obese status, and systolic and diastolic blood pressure.

The results suggest that higher prenatal exposure to POPs mixture was associated with higher BMI and body fat, and higher risk of being overweight/obese at preadolescence, with no evidence of sex difference. HCB was the main contributor to these effects, followed by β-HCH and p,p’-DDE. β-HCH and p,p’-DDE were also associated with higher systolic blood pressure, especially in girls.

Charline Warembourg, last author of the study, say that “these findings confirm that prenatal exposure to organochlorine pesticides is associated with an increased risk of obesity, until adolescence.” She adds that “it is necessary to study whether or not these effects persist in later life”.

Reference: Rouxel E, Costet N, Monfort C, Audouze K, Cirugeda L, Gaudreau E, Grimalt JO, Ibarluzea J, Lainé F, Llop S, Lopez-Espinosa MJ, Rouget F, Santa-Marina L, Vrijheid M, Chevrier C, Casas M, Warembourg C. Prenatal exposure to multiple persistent organic pollutants in association with adiposity markers and blood pressure in preadolescents. Environ Int. 2023 Jun 22;178:108056. doi: 10.1016/j.envint.2023.108056. Epub ahead of print. PMID: 37379720.

Link to scientific article: https://doi.org/10.1016/j.envint.2023.108056