An Unhealthy Legacy: Modifiable Health Risks for Chronic Disease and The Role of Childhood Adversity

Abstract

Alcohol consumption, smoking, excess body weight and physical inactivity are modifiable lifestyle-related health risk factors that are regularly conceptualised as separate problems to be addressed. These lifestyle risks are cumulatively linked to increased likelihoods of chronic disease and all-cause mortality. Understanding lifestyle risks and their patterns of co-occurrence within individuals and populations is critical to maximizing interventions and public health action. This thesis seeks to improve our understanding of multiple co-occurring health risks for chronic disease and their determinants across the life-course.

Through a life-course perspective lenses, this thesis progressively unpacks the accumulation of multiple concurrent lifestyle risks over the lifespan. Starting with a cross-sectional surveillance snapshot across the adult life stage, this thesis describes co-occurrence patterns and examines clustering of lifestyle risks. It explores socio-demographic determinants of health harming lifestyle patterns and identifies vulnerable populations. The second half of this thesis examines the early life influence of adverse childhood experiences on the development of lifestyle risks in adulthood and the relation to adult life sociodemographic factors. Relative effects of specific forms of childhood adversity on concurrent lifestyles risks are examined to better understand the dose-response relations between adverse experiences and the accumulation of multiple lifestyle risks over time. This thesis uses data from the Personality and Total Health (PATH) through life study, a longitudinal health study which examines three narrow age-cohorts residing in the Australian Capital Territory and surrounding regions over 12 years. Results showed that lifestyle risk factors co-occur and cluster relative to age and gender. Specific demographic groups had greater likelihoods of multiple co-occurring lifestyle risks across the life-course. This thesis emphasises the need to consider a comprehensive lifestyle perspective which encompasses multiple unhealthy behaviours when developing health intervention strategies. Smokers should be considered as a key target group for multi-domain lifestyle interventions given the statistical interrelatedness of smoking with other health harming behaviours.

The impact of early life experiences of adversity were found to persist far into adulthood. Results showed that cumulative adverse childhood experiences appears to compound the acquisition of health risk factors in adulthood; and therefore disproportionately increases the risk of chronic disease among those who have experienced childhood adversity. Childhood adversity predicted a greater number of concurrent lifestyle risks in adulthood, but total risk factor trends did not significantly change over time, relative to the experience of childhood adversity. Increased years of education reduced the likelihood of concurrent health risks, but interactions suggest that the protective effects of education may be diminished among those who experienced childhood adversity. Protective childhoods are therefore a critical factor in the development of resilience to health harming lifestyles in adulthood and reinforces the necessity of adopting a life-course approach to chronic disease prevention.

Improving the health of a population requires understanding the interconnectedness of a complex array of factors, interactions and accumulations of effects and experiences across the lifespan. It is hoped that this work will improve understandings of modifiable health risks and contribute knowledge to promote a healthier population through a life-course perspective to chronic disease prevention.