Associations of Polypharmacy and Anticholinergic Burden With Inflammation Among US Older Adults: A Population-Based...

Polypharmacy and anticholinergic burden (AB) are highly prevalent among older adults and have been linked to adverse health outcomes. However, their associations with systemic inflammation remain insufficiently characterized.

Population-based cross-sectional study.

Data were obtained from the US National Health and Nutrition Examination Survey (1999-2020). A total of 11,647 adults aged 65 years or older who reported prescription medication use were included.

Polypharmacy was defined by prescription medication count, and AB was evaluated using multiple established AB scales. Systemic inflammation was evaluated using C-reactive protein (CRP), high-sensitivity CRP, fibrinogen, and 6 composite indices derived from blood cell counts. Correlation matrices and weighted multivariable linear regression models were used to examine associations.

After full adjustment, hyperpolypharmacy was associated with approximately 40% higher CRP levels (P < .001), whereas polypharmacy alone was not independently associated with CRP (P = .113). Higher AB assessed using the Anticholinergic Cognitive Burden Scale, Anticholinergic Drug Scale, and Anticholinergic Risk Scale, as well as anticholinergic medication use, was associated with approximately 16% to 44% higher CRP levels (all P < .050). Associations with high-sensitivity CRP were observed primarily for the Anticholinergic Cognitive Burden Scale (P = .004), whereas associations with fibrinogen were most evident for the Anticholinergic Drug Scale (P = .030). Joint-effect analyses further showed that polypharmacy without AB was not associated with CRP, whereas the co-occurrence of polypharmacy and AB was associated with the highest CRP levels.

Among US older adults, AB was consistently associated with elevated systemic inflammation, particularly in the context of polypharmacy. These findings underscore the importance of considering anticholinergic properties in geriatric pharmacotherapy.