Lay summary

Early life is considered a period of amplified susceptibility to adverse effects of exogenous and endogenous causes of diseases. Many chronic diseases, such as cardiovascular and respiratory diseases, occurring in later life may in part be explained by priming factors experienced in early life and tracking of risk factors into older age.

Within the frame of the Swiss Study on Air Pollution and Health In Adults cohort (SAPALDIA) the  SAPALDIA Youth Study, a retrospective cohort, recruited 360 offspring or of SAPALDIA participants.

The SAPALDIA Youth Study  can bridge time periods, early life and adolescence, by using the parental data as proxies for the early life environment of the offspring. The study aims at investigating the impact of early life and cumulative life-time ETS exposure on vascular health in childhood, measured by intima media thickness. The intima media thickness is considered an early marker of atherosclerosis in all ages. An increasing body of evidence documents the importance of childhood risk factors on the development of atherosclerosis in adults. Most studies in children have focused on metabolic and hemodynamic factors of early arterial injury. Early exposure to tobacco smoke, a major predictor of adult atherosclerosis, has only scarcely been studied, although ETS is known to be associated with adverse birth outcomes, respiratory disease in childhood and cardio-metabolic risk factors.

The SAPALDIA Youth Study is based on the hypothesis that ETS exposure in pregnancy and childhood is associated with an increased intima media thickness, and further that the effect is amplified by recurrent childhood infectious diseases and chronic subclinical inflammation. These hypotheses will be tested in the collected data in offspring, aged 10-20 years. Parental smoking status and home ETS exposure, collected prospectively in 1991 and 2001, will serve as proxy for the youth's ETS exposure in childhood.

The SAPALDIA Youth Study aims at a better understanding of the complex exogenous and endogenous risk factors of chronic diseases. ETS exposure in children continues to be highly prevalent and a major public health concern. Hence, the main aim of the proposed study is to investigate the role of early life ETS exposure in atherogenesis and thereby to contribute to the knowledge of adverse ETS effects on children's health and essentially to the prevention of cardiovascular disease.