Dysfunction in Olfactory Identification and Physical Function Decline in Older Adults.

Abstract

Few longitudinal studies have examined the association of olfactory dysfunction with future decline in physical function. To examine cross-sectional and longitudinal associations between olfaction and physical function among older adults (age ≥65 years). 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. 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). 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. 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). 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.