Understanding the pathways linking childhood trauma to cardiometabolic risk among low-and-middle-income youth: a mixed methods investigation

Individuals who have been exposed to trauma in childhood are at increased risk of poor physical health in later life, particularly including heart problems, high blood pressure and type 2 diabetes. Together these problems are known as 'cardiometabolic diseases'. The development of cardiometabolic disease is strongly related to lifestyle, with certain 'health risk behaviours' being important - for example, smoking, poor diet, poor sleep and lack of exercise. However, how and why childhood trauma leads to health risk behaviours and cardiometabolic disease is not well understood. We propose to complete an in-depth analysis of the potential role of mental health problems in linking childhood trauma to cardiometabolic disease. Childhood trauma exposure has been found to contribute to risk for multiple different mental health problems and is one of the most significant risk factors for poor mental health that has been identified to date, accounting for nearly half of all childhood-onset and a quarter of all adult-onset mental disorders. We also know that some risky behaviours (e.g., problematic drug or alcohol use) are much more common in people who have mental health problems. We want to learn more about whether poor mental health is a factor that links childhood trauma to cardiometabolic disease risk. We will carry out our research in Brazil, building on a study that already exists there. It is important to carry out research in countries like Brazil as most research on childhood trauma focuses on wealthier countries like the UK and the USA, where trauma exposure is less common and tends to be less severe. Cardiometabolic disease is also a major problem in Brazil and other middle and low income countries. The Pelotas 2004 Birth Cohort Study has been tracking more than 4000 individuals since birth, with trauma exposure, mental and physical health, and health risk behaviours each being measured repeatedly since childhood. Participants in this study are now approaching 21 years of age and we will be able to use the data that have already been collected to examine whether trauma exposure leads to poor mental health, and whether this in turn increases risk for cardiometabolic disease. Because participants are still only young adults, very few will have clear signs of cardiometabolic disease, so we will be focusing on the health risk behaviours that lead to those problems (e.g., smoking or physical inactivity). In addition to examining whether and how childhood trauma, mental health and health risk behaviours are associated with each other across childhood and adolescence, we will be carrying out in-depth interviews with a small group of study participants who have experienced these problems, in order to learn about their personal perspectives on why and how they have been affected. Because our research will help us to understand when and how childhood trauma leads to risk of cardiometabolic disease, it will also tell us what we might do to prevent this outcome and when might be a good time to do it. As mental health problems and health risk behaviours are each possible to change, we may ultimately find new ways to break the link between childhood trauma and poor physical health.