This thesis examined the role of lifestyle behaviours to healthy ageing in Latin American settings. The investigations were conducted in several stages. Older people constitute a considerable proportion of the total population, with more than 900 million people aged 60 years old living worldwide and their number is projected to grow. This demographic transition is having a societal and economic impact. Several studies suggest a beneficial effect of a healthy lifestyle behaviour to healthy ageing. Nevertheless, a recent systematic review reporting on the longitudinal associations of physical activity, smoking and alcohol consumption was not available. To fill this knowledge gap, in the first stage of this thesis, a systematic review was conducted together with meta-analysis to provide aggregated results of the associations. Physical activity and non-smoking were positively associated with better ageing. Associations with alcohol consumption were equivocal and pooled results showed a slight beneficial effect of limited alcohol consumption. This first line of research indicated the heterogeneity in the definition and measurement of healthy ageing, in the assessment of lifestyle behaviours and the limited research in Latin American and Caribbean countries. Considering the findings from the systematic review and the fact that projections show that Latin American countries are going to experience the fastest growth of the older population in the next years, the second line of research examined healthy ageing among older adults in Latin American settings (10/66 study). Healthy ageing was conceptualised within the functional ability framework provided by the World Health Organization. Latent variable modelling was employed to build a healthy ageing index. Analyses in the 10/66 study produced a latent construct reflecting healthy ageing with good psychometric properties (reliability, replicability, and measurement invariance among countries and 4 men and women). The latent metric of healthy ageing showed associations with mortality and onset of dependence. The third line of investigations informed on the longitudinal associations of lifestyle behaviour with healthy ageing in populations from Latin American countries. This research was conducted in two separate studies: the 10/66 study with a median follow-up duration of four years (using the healthy ageing index produced in the second stage of this thesis and logistic regression to estimate the associations) and the Mexican Health and Aging Study (MHAS) with four available waves of follow-up across 14 years (using a Bayesian multilevel Item Response Theory model to quantify healthy ageing across the four waves and Growth Mixture Modelling to identify heterogeneous ageing trajectories and the impact of lifestyle behaviour on those). Findings from the 10/66 cohort suggested that participants engaging in physical activity and in fruits and vegetable consumption have increased odds of ageing by maintaining good health. Participants engaging in all four healthy lifestyle habits (physical activity, non-smoking, moderate alcohol consumption and fruits and vegetable consumption) showed the highest likelihood of healthy ageing. Four trajectories of ageing were identified in the MHAS cohort. Physically active participants, those with smoking abstinence and those endorsing in some alcohol consumption were associated with trajectories exhibiting better health and lowest risk of mortality. In conclusion, findings from this thesis show that lifestyle behaviours play a role in the way older participants from Latin American countries age in the short term (10/66 cohort) and in the long-term (MHAS cohort). In addition, healthy ageing metrics conceptualised within the functional ability framework can provide insight into vulnerable old populations from Latin American settings and contribute to the identification of those in higher risk of adverse health outcomes (onset of dependence, mortality).
An investigation of lifestyle behaviours and healthy ageing in Latin American countries
Daskalopoulou, C. (Author). 1 Apr 2019
Student thesis: Doctoral Thesis › Doctor of Philosophy