Combined impact of lifestyle-related factors on total mortality among the elder Chinese: a prospective cohort study

BACKGROUND: The combined impact of healthy lifestyle factors on total mortality among elder Chinese is unclear. This study aimed to investigate the overall impact of lifestyle factors on total mortality in a senior Chinese population, and determine whether these associations were consistent in the presence of different characteristics, including physical comorbidities. METHODS: The Chinese Longitudinal Healthy Longevity Survey (CLHLS) is a large population-based prospective cohort study in 22 of 31 provinces from mainland China. We included 15,163 adults aged ≥65 years recruited from 1998- to 2002 and followed-up until 2014. A healthy lifestyle score was calculated considering five lifestyle factors (exercise, smoking, dietary diversity, body mass index and drinking). The scores ranged from zero to five points and were classified into the following three categories: unhealthy (0-1 point), intermediate (2-3 points) and healthy (4-5 points). Cox proportional hazards regression analyses were used to assess the associations between the combined healthy lifestyle score and total mortality, adjusting for demographic characteristics and physical comorbidities, as appropriate. Stratification analyses and interaction analyses were further performed. RESULTS: Among the 15,163 participants, the mean age (SD) was 86.2 (11.6) years. During an average follow-up period of 12.5 (SD = 3.9) years, 9655 deaths occurred. The adjusted hazard ratios (HRs) of total mortality decreased as the number of healthy lifestyle factors increased. Compared to the unhealthy lifestyle group, the healthy lifestyle group had a HR and 95% CI of 0.78 and 0.72-0.83. The population attributable risk of total death among those without a healthy lifestyle was 25.2%. A healthier lifestyle pattern was associated with a lower total mortality risk among individuals with different severities of physical comorbidities, although the associations were stronger among those with fatal physical comorbidities (p(-interaction) < .001). CONCLUSIONS: In this large-scale study, a healthier lifestyle measured by regular exercise participation, never smoking, never drinking, good dietary diversity and normal weight, was inversely associated with total mortality, regardless of physical comorbidity status. These findings support the necessity of multiple lifestyle modifications to prevent premature death in both general elderly populations and those with physical comorbidities. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-022-02982-z.