\\(Background:\\) Understanding the epidemiology of alcohol consumption across the life course is important for better estimating the associations between alcohol and diseases. There is a need for more studies of how alcohol consumption, including alcohol use disorders, evolves over time and the factors influencing any changes. \\(Aims:\\) This thesis aimed to address novel aspects of the epidemiology of alcohol consumption and related health effects across the life course. \\(Methods:\\) Data were from a large population-based cohort study, the Childhood Determinants of Adult Health (CDAH) study. Around 2,500 Australians aged 7‚Äö-15 years in 1985, aged 26‚Äö-36 years in 2004‚Äö-06 and aged 31-41 years in 2009-10 were assessed over time. Measurements included alcohol consumption, alcohol use disorders, anthropometry, blood biochemistry, metabolic syndrome (MetS) and its individual risk factors, carotid-intima media thickness, insulin resistance, metabolomics signatures, physical activity, cardiorespiratory fitness, and other covariates. \\(Results:\\) Alcohol consumption was very common in this cohort of young adults. People consuming light to moderate amounts of alcohol also had a host of other concurrent health behaviours such as better diet quality, greater amounts of total physical activity, lower prevalence of depression/anxiety compared to their non-drinker or heavy drinker counterparts. A summary of the key findings for each study are below. Study 1: Cross-sectional analyses in 2,220 participants aged 26 to 36 years in 2004-06 showed that moderate alcohol consumption was associated with a lower prevalence of metabolic syndrome compared to light drinkers, but higher levels of blood pressure and glucose. Alcohol consumption was associated with both favourable and unfavourable effects on cardio-metabolic risk factors in young adults. Study 2: Cross-sectional analyses in 2,220 participants aged 26 to 36 years in 2004-06, found three patterns of alcohol consumption. These patterns were not associated with carotid intima media thickness or insulin resistance, suggesting that the most common way that younger people consume alcohol was not associated with cardiovascular or metabolic health benefits. Study 3: Cross-sectional analyses in 1,785 participants aged 26 to 36 years in 2004-06 showed that a diverse range of metabolomics signatures potentially associated with benefits and harms to health were associated with alcohol consumption. Associations with the metabolomic profile were similar between total alcohol and types of alcohol consumed (beer and wine) and also with adjustment for a range of covariates. Study 4: Longitudinal analyses in 2,031 participants aged 26 to 36 at baseline in 2004-06 showed that greater levels of physical activity at baseline predicted an increase in alcohol consumption 5 years later in 2009-11. In 1,322 participants at baseline in 2004-06, higher alcohol consumption predicting a decrease in total physical activity over 5 years of follow-up. There were therefore bidirectional associations between physical activity and alcohol consumption in adulthood were found. Study 5: Longitudinal analyses in 2,239 participants showed that childhood physical activity and sport participation in 1985 was positively associated with adulthood alcohol consumption 20 years later in 2004-06. People in the middle and highest thirds of cardiorespiratory fitness (CRF) in childhood had a higher risk of being diagnosed with an alcohol use disorder (AUD) in adulthood. \\(Conclusions:\\) The inter-relationships across the life course between alcohol consumption and other risk behaviours, particularly physical activity and cardiorespiratory fitness, are highly relevant to current debates regarding the nature of the association between alcohol and a range of health outcomes. The findings support recent publications demonstrating that alcohol consumption has fewer benefits for traditional cardiovascular risk factors than previous thought once potential confounders are considered. There did, however, appear to be a range of beneficial and harmful metabolic pathways associated with alcohol consumption independent of covariates. These findings may aid interpretation of recent data showing the alcohol consumption decreased the risk of myocardial infarction but increases the risk of strokes. These findings strengthen the case for modifying guidelines and public health messages regarding alcohol consumption to better acknowledge its favourable and adverse effects in relation to cardiovascular risk.
Copyright 2018 the author Chapter 3 appears to be the equivalent of a pre-print version of an article published as: Du, D., Bruno, R., Dwyer, T., Venn, A., Gall, S. 2017. Associations between alcohol consumption and cardio-metabolic risk factors in young adults, European journal of preventive cardiology, 24(18), 1967-1978 Chapter 5 appears to be the equivalent of a pre-print version of an article published as: Du, D., Bruno, R., Blizzard, T., Venn, A., Dwyer, T., Smith, K. J., Magnussen, C. G., Gall, S. 2019. The metabolomic signatures of alcohol consumption in young adults, European journal of preventive cardiology, published online March 11 2019, https://doi.org/10.1177/2047487319834767