2025 年 62 巻 2 号 p. 71-77
Cardiovascular dysfunction has been suggested as a risk factor for olfactory dysfunction in older adults; however, the details remain unclear. This study investigated whether older adults with reduced cardiac autonomic function during orthostatic stress exhibit a lower olfactory discrimination ability. In total, 100 community-dwelling older adults living independently, and aged 60 years or older participated in this study. The cardiac autonomic function, which contributes to the baroreflex response, was assessed by evaluating the heart rate increase during the postural change from sitting to standing (i.e., ∆HRmax). Subsequently, the participants were divided into small and large response groups based on the average ∆HRmax. The olfactory function was evaluated by testing the ability to discriminate between similar-smelling odorants. The study compared the olfactory function of the participants with declining cardiac autonomic function, separately in the young-old (age < 75) and old-old (age ≥ 75) groups. The mean ∆HRmax was 8.1 ± 3.5 (mean ± SD) beats per minute. A significantly higher number of participants in the smaller ∆HRmax group than in the larger ∆HRmax group could not discriminate between odorants. This trend was evident in both age groups but was more pronounced in the old-old group. The present results revealed that older adults with a smaller heart rate response to standing have impaired olfactory function, especially after 75 years of age.
