Leading Determinants of Healthy Ageing in Community-Dwelling Middle-Aged Men and Women: A Cohort Study

Abstract

Background: Identifying leading determinants of healthy ageing may provide evidence for action priorities, which is imperative for public health with an expanding aged population worldwide. Methods: We included 52,036 participants aged 45-64 years from the 45 and Up Study who were free of 13 predefined chronic conditions at baseline (2006-2009). Healthy ageing was defined as the absence of developing any of these chronic conditions during follow-up until 2016. We used machine learning methods to evaluate the importance of potential predictors and analyzed the association between the number of leading modifiable healthy factors and healthy ageing. Findings: Healthy ageing was found in about half of both men and women during a mean nine-year follow-up. The five most common leading predictors were body mass index (6·4-9·5% of total variance), self-rated health (5·2-8·2%), self-rated quality of life (4·1-6·8%), red meat intake (4·5-6·5%), and chicken intake (4·5-5·9%) in both genders. Modifiable behavioral factors including body mass index, diets, smoking, alcohol consumption and physical activity, contributed to 37·2-40·3% of total variance. Participants having six or more modifiable healthy factors were 1·63-8·76 times more likely to remain healthy ageing and had 0·60-2·49 more healthy ageing years (out of nine-year follow-up) than those having two or fewer. Non-behavioral factors including low levels of education, income and relative socioeconomic disadvantage, were leading risk factors for healthy ageing. Interpretation: Body mass index, diets, smoking, alcohol consumption and physical activity are key factors for healthy ageing promotion. Individuals with low socioeconomic status are more in need of care. Funding: Professor Mingguang He receives support from the University of Melbourne at Research Accelerator Program and the Centre for Eye Research Australia Foundation. The Centre for Eye Research Australia receives Operational Infrastructure Support from the Victorian State Government. The specific project is funded by Australia China Research Accelerator Program at Centre for Eye Research Australia. Professor Mingguang He is also supported by the Fundamental Research Funds of the State Key Laboratory in Ophthalmology, National Natural Science Foundation of China (81420108008). The sponsor or funding organization had no role in the design or conduct of this research. Declaration of Interest: We declare no competing interests. Ethical Approval: The 45 and Up study has ethical approval from the UNSW Human Research Ethics Committee. The study protocol was approved by the Royal Victorian Eye and Ear Hospital Human Research Ethics Committee. Participants provided consent to follow-up and link their data to routine health datasets.