Association between combined lifestyle factors and healthy ageing in Chinese adults: the Singapore Chinese Health Study.

BACKGROUND To examine the relations of individual lifestyle factors and its composite score with healthy ageing among Chinese. METHODS We included 14,159 participants aged 45-74 years at baseline from the Singapore Chinese Health Study, a population-based prospective cohort. A protective lifestyle score (0-5 scale) was calculated at baseline (1993-1998) and updated at the second follow-up visit (2006-2010) on the basis of optimal body mass index (18.5-22.9 kg/m2), healthy diet (upper 40% of the Alternative Healthy Eating Index score), being physically active (≥2 hours/week of moderate activity or ≥0.5 hours/week of strenuous activity), non-smoking (never smoking), and low-to-moderate alcohol drinking (>0 to ≤14 drinks/week for men and >0 to ≤7 drinks/week for women). Healthy ageing was assessed at the third follow-up visit (2014-2016), and was defined as absence of specific chronic diseases, absence of cognitive impairment and limitations in instrumental activities of daily living, good mental and overall self-perceived health, good physical functioning, and no function-limiting pain. RESULTS About 20.0% (2,834) participants met the criteria of healthy ageing after a median follow-up of 20 years. Each one-point increase in the protective lifestyle score computed at baseline and second follow-up visits was associated with higher likelihood of healthy ageing by 25% (95% CI: 20%-30%) and 24% (18%-29%), respectively. The population-attributable risk percent of adherence to 4-5 protective lifestyle factors was 34.3% (95% CI: 25.3%-42.3%) at baseline and 31.3% (23.0%-38.7%) at second follow-up visits for healthy ageing. In addition, positive increase in lifestyle scores from baseline to second follow-up visits was also significantly associated with a higher likelihood of healthy ageing with an odds ratio of 1.18 (95% CI: 1.12-1.24) for each increment in protective lifestyle score. CONCLUSIONS Our findings confirmed that adopting healthy lifestyle factors, even after midlife, was associated with healthy ageing at old age.