Friedman et al., 2015. Inflammation Partially Mediates the Association of Multimorbidity and Functional Limitations in a National Sample of Middle-Aged and Older Adults: The MIDUS Study


Objective: Older adults are increasingly likely to have two or more chronic medical conditions (multimorbidity) and are consequently at greater risk of disability. Here we examine the role of inflammation in mediating the relationship between multimorbidity and disability. 

Method: Data are from the Survey of Mid-Life in the United States (MIDUS), a national sample of middle-aged and older adults. Structural equation models were used to assess direct relationships between multimorbidity and activities of daily living as well as indirect associations with a latent variable for inflammation (indicated by circulating levels of interleukin-6, C-reactive protein, and fibrinogen) as a mediator. 

Results: After adjustment for potential confounds, multimorbidity was positively associated with inflammation (p < .001) and functional limitations (p < .001), and inflammation partially mediated the link between multimorbidity and functional limitations (p < .01). 

Discussion: Inflammation may be an important biological mechanism through which chronic medical conditions are linked to disability in later life.