Twin research and environmental geocoding to unravel nature vs nurture

Abstract

This research was conducted to investigate the effect of the early-life environment of twins, i.e. residential exposure to air pollution, traffic and greenness, on outcomes at birth and at adulthood. We investigated the exposure at the maternal residential address during pregnancy and its effect on birth weight and biomarkers of ageing in placental tissue, i.e. mitochondrial DNA content and telomere length. Next, we intend to unravel the nature-nurture contribution to these biomarkers of ageing. Twin research provides this opportunity to gain insight in the relative importance of genes and environment. In addition, we also studied the relation between of the early-life environment and blood pressure or telomere length in young adulthood. Both parameters are associated with the development of cardiovascular disease. We hypothesize that an adverse early-life environment will increase the risk of disease later in life. Although numerous studies have investigated the health effects of air pollution exposure in adults, knowledge on the effects of the early-life environment on birth outcomes, ageing, and disease outcome later in life is limited. The overall hypothesis of this doctoral dissertation is that exposure in the early-life environment of twins affects outcomes both early and later in life. Our results indicates that residential greenness during the early-life environment has persistent effects on blood pressure. We observed that prenatal exposure to air pollution and traffic was respectively associated with a suboptimal fetal growth and a change in placental biomarkers of ageing. Besides these outcomes at birth, we noted that exposure to traffic early in life was associated with shorter telomere length in young adulthood and that surrounding greenness in early-life is associated with a lower blood pressure in adulthood.