AUTHOR=Katayama Naomi , Yoshida Tadao , Nakashima Tsutomu , Ito Yasuki , Teranishi Masaaki , Iwase Takeshi , Sugiura Saiko , Goto Kensuke , Uchida Yasue , Taki Yosuke , Nakada Takafumi , Tada Ai , Suzuki Hirokazu , Nakano Yuta , Shimono Mariko , Saji Naoki , Kogure Anna , Shimizu Emiko , Sone Michihiko , Hamajima Nobuyuki 

TITLE=Relationship between tinnitus and olfactory dysfunction: audiovisual, olfactory, and medical examinations

JOURNAL=Frontiers in Public Health

VOLUME=Volume 11 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2023.1124404

DOI=10.3389/fpubh.2023.1124404

ISSN=2296-2565

ABSTRACT=Abstract
Introduction
Sensory dysfunctions and cognitive impairments are related to each other. A relationship between tinnitus and subjective olfactory dysfunction was reported, but there have been no reports about the relationship between tinnitus and olfactory test results. 

Methods
We investigated the relationship between tinnitus and olfactory test results, including other sensory tests: hearing and visual examinations. The subjects were 510 community-dwelling individuals (295 women and 215 men) who attended a health checkup in Yakumo town in Japan. Their ages ranged from 40 to 91 y (mean ± standard deviation, 63.8 ± 9.9 y). A self-reported questionnaire included subjective tinnitus, olfactory, and hearing functions with various lifestyles. Smell, hearing, vision, and blood examinations were performed during the health checkup. 

Results
After adjusting age and sex, tinnitus was significantly associated with subjective olfactory dysfunction, bad olfactory test results, hearing deterioration, vertigo, and headache. The high serum calcium level and low albumin/globulin ratio were also significantly associated with low physical activity and nutrition. Women scored higher than men in olfactory and hearing examinations, but there was no gender difference in vision examinations.

Conclusion
Subjective smell dysfunction and bad smell test results were associated significantly with tinnitus complaints. Hearing and vision were associated even after adjusting age and sex. Accordingly, we should consider mutual relationships among the sensory organs in evaluating the influence of sensory dysfunctions on cognitive function.