The regulatory roles of socio-economic status, social and intellectual activity in the relationship between alcohol consumption and cognitive decline trajectory in middle-aged and elderly Chinese: A prospective cohort study.

OBJECTIVES

To determine the relationship between alcohol consumption and cognitive decline, and to further explore the potential regulatory role of education, socio-economic status (SES), and social or intellectual activity in this relationship.

METHODS

6197 participants aged 45-75 years with four repeated measures data from 2011 to 2018 were included. A mixed-effect model was used to explore the relationship between alcohol consumption and the rate of change in cognitive decline, a latent class growth mixed model (LCGMM) was applied to determine the potential trajectory of cognitive decline, and finally, the mediating and moderating analyses were used to determine the regulatory effect of all four variables on the relationship between alcohol consumption and potential trajectory.

RESULTS

Compared to never-drinkers, moderate alcohol consumption was a protective factor for overall cognitive function (β = 0.13, 95% CI: 0.04-0.20, p < 0.001), but there was no statistical correlation with the decline rate of cognitive function. And this protective effect was no longer significant after additional adjustments for education, SES, social and intellectual activity. The LCGMM model divided participants into two trajectories, a high-level-to-decline group including 79.75% of participants (quadratic: β [SE]: -0.90 [0.07], p < 0.001), and a low-level-to-decline group including 20.25% participants (linear: β [SE]: -3.05 [0.49], p < 0.001). With the latter as the reference, SES played a reverse regulation role in the harmful effect of heavy drinking on cognitive trajectories (odd ratio [OR] = 0.46, 95% CI: 0.23-0.93, p < 0.05). Social and intellectual activities played a negative mediating role in the harmful effect of alcohol consumption on cognitive trajectories (light: OR = 0.96, p < 0.001; moderate: OR = 0.96, p < 0.001; heavy: OR = 0.97, p < 0.01).

CONCLUSIONS

Alcohol itself has no protective effect on the decline of longitudinal cognitive trajectory. But the regulatory effect of SES, social and intellectual activities slows down the harm of alcohol consumption on the decline of cognitive function.

CLINICAL TRIAL REGISTRATION

The data used in this study are from publicly available databases. They are retrospective cohort studies without any intervention. Therefore, no clinical trial registration has been conducted.