Early-life exposure to Persistent Organic Pollutants (POPs) and cardiometabolic risk

Over the past 20 years, a vast number of studies show a significant global increase in the prevalence of cardiometabolic diseases and their associated risk factors, such as hypertension, dyslipidemia, hyperinsulinemia, obesity, and type 2 diabetes. The prevalence of overweight and obesity in children has increased globally and concerns both developing and developed countries (Ng et al. 2014). Therefore, it is needed to identify and act as early as possible on the risk factors of cardiometabolic health disorders.
Exposure to different chemical compounds in the environment from fetal life and throughout the early life demonstrates health consequences over varying lengths of time. Because of this, it is essential to focus on early prenatal and childhood exposures as a determinant of future health status (Charles, Delpierre, et Bréant 2016). In addition, pregnant women and children are exposed to a large number of chemicals, which are suspected to have the potential to affect the cardiometabolic and endocrine system (Braun 2017). Among these chemicals, persistent organic pollutants (POPs), including organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs), were of particular concern. Even if most of them were banned several decades ago, POPs are present in many environmental compartments because their lipophilic characteristics cause bioaccumulation in living organisms and thus contaminate human food (Lee et al. 2014).
Many studies have demonstrated the effect of exposure to POPs on cardiometabolic health in the general population (Dusanov et al. 2018) (Lee 2012) and a number of epidemiological studies have investigated the effects of prenatal exposure to POPs on childhood growth and obesity (Stratakis et al. 2022). The strongest evidence relates to prenatal exposure to dichlorodiphenyldichloroethylene (DDE) and hexachlorobenzène (HCB) – but not PCBs – that were associated with a higher BMI z-score in childhood (Stratakis et al. 2022). However, for others obesity outcomes (e.g., % of fat mass) the results varied due to the limited number and methodological heterogeneity of the studies. Finally, only a limited number of studies stratified their analyses by sex, not allowing to conclude about potential sex-specific effect of POPs (Stratakis et al. 2022).
Current epidemiological knowledge of metabolic score and its indicatorssuch as dyslipidemia or insulin resistance is limited, inconsistent, and mainly based on cross-sectional studies (or not perinatal exposure)(Vrijheid et al. 2016). Indeed, among these few studies, some showed that maternal exposure to POPs was associated with decreased insulin, adiponectin and HDL-C and increased LDL-C/HDL-C ratio (Tang-Péronard et al. 2015; Berghuis et al. 2022; Debost-Legrand et al. 2016). But another study showed that maternal exposure to certain POPs was associated with lower levels of triglycerides, LDL-C and total lipid during childhood, suggesting increased accumulation of lipids in the liver (Boutot et al. 2021).
These previous findings demonstrate the interest to pursue research studies on the role of prenatal exposures to POPs in the cardiometabolic health of children, up to the adolescence, a key developmental period subjects to important physiological and endocrine changes. The large number of participants in the pooled cohorts of the ATHLETE project will make it possible to study the effect of POPs on cardiometabolic risk at different ages and by sex in an attempt to highlight heterogeneous responses. The question of POP mixture will also be explored in this analysis.