Olfactory Ability in the Healthy Population: Reassessing Presbyosmia

A Mackay-Sim,T H J Burne,A N B Johnston,C Owen

doi:10.1093/chemse/bjl019

A Mackay-Sim, T H J Burne + Show 2 more

Open Access

https://doi.org/10.1093/chemse/bjl019

Copy DOI

Abstract

Age-associated loss of olfactory function, or presbyosmia, has been described in many studies of olfactory ability. Presbyosmia has been ascribed to idiopathic causes despite recognition that many neurodegenerative diseases also induce loss of olfactory function and increase in incidence in the aged population. Often this olfactory loss is unnoticed or unreported by affected individuals. More effective olfactory function in women compared with men is another common feature of many studies of olfactory function. Here we report on normative data from an Australian population study (n = 942) that has been divided into 2 subpopulations and reassessed as (included) a population of healthy, nonmedicated, nonsmokers with no history of nasal problems (n = 485) and (excluded) a population of participants who were either medicated, smokers or had a history of nasal problems (n = 457). The "included" data set shows a strong relationship between self-reporting of olfactory sensitivity and olfactory function score. The included data set shows a small but significant decline in olfactory ability after 65 years of age and better olfactory function in females compared with males. Data from the excluded population show a marked decline in olfactory ability after 65 years of age, no difference between males and females, and a weak relationship between self-reporting of olfactory function and actual olfactory function. The power of this approach is that it provides a normative data set against which many factors such as medication schedules and pathological conditions can be compared.

Highlights

The gradual, idiopathic, decrease in sensory function as humans age has been described in many studies and in many contexts (Nusbaum 1999)
On the basis of a questionnaire associated with that study, the data on olfactory function from the original study population were divided into subpopulations according to factors that, a priori, might reasonably be expected to alter olfactory ability, such as medication (MED; listed in Table 1), history of nasal problem, and smoking (SMOK) status
Our results suggest that the population of nonsmoking, nonmedicated people with no history of nasal problems should be taken as the appropriate normative population with which to compare other subpopulations

Summary

Introduction

The gradual, idiopathic, decrease in sensory function as humans age has been described in many studies and in many contexts (Nusbaum 1999). He recognized that ‘‘despite the likelihood of different physiological bases for these changes, the quality of suprathreshold sensory perception diminishes in these 3 (vision, audition, and olfaction) senses in the later years,’’ while recognizing that olfactory ability is extremely vulnerable to environmental insult and neurodegenerative change. Since this seminal work, increasing numbers of studies have recognized decreased olfactory function as a key diagnostic feature in, even representative of, a number of neurodegenerative disorders, most Parkinson’s Disease (Hawkes et al 1997; Kovacs 2004)

Objectives

Methods

Findings

Discussion

Conclusion