Oxidants and antioxidants as targets for cardiovascular disease prevention: evidence from observational and causal inference studies

Abstract

The prevalence of cardiovascular diseases has increased in the last decennia. This thesis studied the potential relationship between oxidative stress and cardiovascular diseases. The first part of the thesis focused on anti-oxidants, which are scavengers that protect against oxidative damage. We studied the association between several lifestyle factors, diet, physical activity, sleep, alcohol intake and smoking, and antioxidant levels both in blood and urine. Subsequently, we investigated whether a higher concentration of antioxidants leads to a decrease in ischaemic stroke occurrence. Next, we aimed to study a possible cause of oxidative damage and its effect on cardiovascular disease. Mitochondrial dysfunction is one of the mechanisms that may underly this effect. Mitochondria are an important source of Reactive Oxygen Species (ROS), as an inevitable byproduct of their essential role in energy production. A disbalance in ROS production and scavenging might result in oxidative damage. Thus, we investigated the causal association between mitochondrial dysfunction and stroke using the Mendelian Randomization method. Finally, we studied how socio-demographic traits could modify the causal association between CVD risk factors and coronary artery disease.