Dysfunction in Olfactory Identification and Physical Function Decline in Older Adults

Importance: Few longitudinal studies have examined the association of olfactory dysfunction with future decline in physical function. Objective: To examine cross-sectional and longitudinal associations between olfaction and physical function among older adults (age ≥65 years). Design, Setting, and Participants: This cohort study used data from the Atherosclerosis Risk in Communities (ARIC) study, a prospective cohort study that enrolled 15 792 adults aged 45 to 64 years from 4 US communities. In the present study, we used data from visits 5 (2011-2013), 6 (2016-2017), and 7 (2018-2019). Data were analyzed July 16, 2025. Exposure: Olfaction was measured using the 12-item Sniffin' Sticks Odor Identification Test (total score range, 0-12) at visit 5 and categorized as good (11-12 [reference]), moderate (9-10), and poor (0-8). Main Outcomes and Measures: Physical function was assessed using the Short Physical Performance Battery (SPPB) overall score (range, 0-12); SPPB subscale scores (range, 0-4) for balance, 4-m usual pace walk, and chair stand; and gait speed at visits 5 (baseline), 6, and 7. Grip strength was assessed at visits 5 and 7. Results: In the analytic sample of 5474 participants (mean [SD] age, 75.3 [5.0] years; 3163 [57.8%] female), the estimated mean difference in total SPPB scores was -0.14 (95% CI, -0.28 to -0.01) among those with moderate vs good olfaction and -0.49 (95% CI, -0.63 to -0.35) among those with poor vs good olfaction. In longitudinal analyses, compared with participants with good olfaction, the estimated mean annual difference in SPPB score was -0.05 (95% CI, 0.08 to -0.02) among those with moderate olfaction and -0.11 (95% CI, -0.14 to -0.08) among those with poor olfaction. Consistent trends were observed across SPPB subscales (eg, balance score: estimated mean difference in poor vs good olfaction, -0.18 [95% CI, -0.02 to -0.12]), gait speed (-0.06 [95% CI, -0.07 to -0.04] m/s), and grip strength (-1.50 [95% CI, -1.98 to -1.01] kg). Conclusions and Relevance: In this cohort study, poor olfaction in older adults was associated with a decline in physical functioning. These findings may have clinical implications for identifying older adults at elevated risk. Future research should investigate biologic mechanisms linking olfactory dysfunction with functional aging.