The impact of hearing loss on cognitive impairment: The mediating role of depressive symptoms and the moderating role of social relationships

Abstract

Background: Given the potentially negative effects of hearing loss on mental health and cognitive function, it is critical to gain a better understanding of the mechanisms underlying the link between hearing loss and cognitive impairment. This study aimed to investigate the moderating effects of social relationships, including their components in the role of depressive symptoms as a mediator between hearing loss and cognitive impairment.

Methods: Cross-sectional analyses were conducted with 8,094 Chinese older adults (aged ≥65 years) from the Chinese Longitudinal Healthy Longevity Survey in 2018. Simple mediation analysis and moderated mediation analysis were conducted to examine the roles of depressive symptoms and social relationships in the association between hearing loss and cognitive impairment.

Results: There is a significant correlation between hearing loss, depressive symptoms, social relationships, and cognitive function. Depressive symptoms partially mediated the association between hearing loss and cognitive function [standardized regression B-coefficient (B) = -0.114; 95% confidence interval (CI): (-0.158, -0.076)]. Social relationships moderated the effect of hearing loss on cognitive function through both path b (depressive symptoms - cognitive function) [B = 0.021; 95% CI: (0.008, 0.034)], and path c' (hearing loss-cognitive function) [B = 0.597; 95% CI: (0.463, 0.730)]. Furthermore, social activities and social networks moderated both the direct and indirect effects of moderated mediation. However, there appeared to be no moderated effect of social support for both the direct and indirect paths.

Conclusion: Social relationships moderated both the direct and indirect effects of depressive symptoms on the association between hearing loss and cognitive impairment. These findings shed light on the mechanisms underlying the relationship between hearing loss and cognitive impairment in Chinese older adults. It might be worthwhile to recommend multidimensional health and social interventions aimed at improving mental health and social inclusion among older adults with hearing loss.

Keywords: cognitive impairment; depressive symptoms; hearing loss; older adults; social relationships.

Figure 1

Flow chart of the selection of study participants.

Figure 2

The final moderated mediation model: social relationships as moderator of the mediation model of depression between hearing loss and cognitive function (Andrew Hayes’s mediation-moderation Model 15, ^*p < 0.05; ^**p < 0.01; ^***p < 0.001). The moderated mediation model was controlled for covariates (age, gender, education level, marital status, lifestyle scores, ADL scores, and physical comorbidities).

Figure 3

The final moderated mediation model: social activities and social networks as moderators of the mediation model of depression between hearing loss and cognitive function (Andrew Hayes’s mediation-moderation Model 76, ^*p < 0.05; ^***p < 0.001). The moderated mediation model was controlled for covariates (age, gender, education level, marital status, lifestyle scores, ADL scores, and physical comorbidities).

Figure 4

The simple plot of path A and B indicating the relationship between hearing loss, depressive symptoms, and cognitive impairment among different levels of social relationships.

Figure 5

The simple plot of path A, B, and C indicating the relationship between hearing loss, depressive symptoms, and cognitive impairment among different levels of social activities and social networks groups.