Effects of polypharmacy on sensory, oral, and dietary functions in older adults

Aim: Polypharmacy is a major health concern among older adults and is associated with increased vulnerability and adverse health outcomes. However, limited evidence exists regarding its association with sensory, oral, and dietary functions. This study examined the effects of polypharmacy on these functions using nationally representative data from the 2023 Korean Elderly Survey. Methods: A total of 10,078 community-dwelling adults aged ≥ 65 years were analyzed. Polypharmacy was defined as the use of five or more medications. Sensory function (vision and hearing), oral function (chewing difficulty, swallowing difficulty, denture use, unmet dental needs), and dietary intake (meal frequency, fruit and vegetable consumption) were assessed using structured questionnaires. Chi-square tests and logistic regression analyses were performed. Model 1 adjusted for demographic factors, and Model 2 additionally adjusted for the number of chronic diseases. Results: Older adults with polypharmacy showed substantially poorer sensory and oral function than those without polypharmacy. Higher prevalence was observed for vision difficulty (60.5% vs. 40.6%), hearing difficulty (48.7% vs. 20.6%), chewing difficulty (58.9% vs. 30.1%), swallowing difficulty (20.9% vs. 6.7%), and unmet dental care needs (9.6% vs. 3.0%) (all p < 0.001). In the fully adjusted model, polypharmacy remained significantly associated with hearing difficulty, chewing difficulty, swallowing difficulty, denture use, and unmet dental care needs. However, associations between polypharmacy and dietary intake indicators were not statistically significant after adjustment. Conclusions: Polypharmacy is significantly associated with hearing and oral functional impairments among older adults, and these associations were attenuated but not fully explained after adjusting for chronic disease burden. These findings highlight the importance of comprehensive geriatric assessment and multidisciplinary care that integrates medication management and oral health. Strategies promoting rational prescribing and monitoring of functional outcomes are essential to mitigate the adverse effects of polypharmacy and support healthy aging.