Independent and Joint Associations of Socioeconomic Status and Lifestyle behaviors with Cognitive Impairment among Elderly Chinese Population.

Abstract

Numerous studies have shown that there are socioeconomic disparities in people's health. Health behavior is considered to be an effective strategy to alleviate socio-economic differences. However, the independent or joint relationship between socioeconomic status (SES) and lifestyle behaviors (LBs) on the cognition of Chinese elderly are not clear. Therefore, this study aimed to reveal the impact of SES and LBs on cognitive impairment in elder Chinese. The data from the 2017-2018 wave of Chinese Longitudinal Healthy Longevity Survey was used. SES was created using latent class analysis based on annual per-capita household income, education level, and occupation. Six LBs were considered in calculating LB scores. Restricted cubic splines were used to model the association of LB scores and cognitive impairment to investigate the dose-response relationship. LB scores were divided into three groups: unhealthy, intermediate, and healthy lifestyle. Multivariate Logistic regression models were applied to explore both the independent and joint effects of SES and LB scores on cognitive impairment. Among 10,116 participants, 1,872 (18.51%) were recorded as having cognitive impariment. After adjusting for multivariable confounding factors, compared with participants of high SES, those of low SES had higher risks of cognitive impairment [Odds ratio (OR): 1.385; 95% confidence interval (CI): 1.137-1.689]. In contrast to those with unhealthy lifestyle, participants adhering to a healthy lifestyle were found to be associated with a reduced risk of cognitive impairment (OR: 0.198; 95%CI: 0.150-0.263). A non-linear relationship was observed between LB scores and cognitive impairment (Pnonlinearity =0.001), indicating a protective effect on cognitive impairment when having more than two LBs. Participants with high SES and engaged in healthy lifestyle had the lowest risk of cognitive impairment compared to those with low SES and unhealthy lifestyle (OR: 0.123; 95% CI 0.073-0.207). Cognitive impairment has socioeconomic disparities among the elderly Chinese population. A healthy lifestyle may attenuate the impact of socioeconomic inequality on cognitive impairment, emphasizing the important role of LBs modification in reducing the disease burden of cognitive impairment, especially in the elderly population with low SES.