Olfactory Dysfunction in Aging Adults

PROJECT SUMMARY/ABSTRACT: Olfactory dysfunction (OD) has been reported in more than 50% of older adults and is strongly associated with 5 year mortality. Unfortunately, a key weakness of prior research on OD in aging is that it comes primarily from broad population health surveys using limited screening tests for OD. The result is that currently there are no methods for organizing patients with OD in aging based on either disease site or mechanism. Various anatomic sites along the olfactory pathway may be involved in OD in aging, including the nasal cavity, olfactory neuroepithelium, olfactory nerves, cribriform plate, and central olfactory structures. At these anatomic sites, OD then likely occurs through distinct mechanisms that will be associated with unique olfactory-specific biomarkers. Although prior studies have been instrumental in demonstrating that OD is highly prevalent in older individuals, most were not designed to comprehensively evaluate the olfactory- specific measures that would allow classification into subtypes of OD. Our hypothesis is that patients with OD in aging can be grouped into clinically relevant phenotypes based on anatomic sites of dysfunction that will provide important mechanistic insights. Our long term objective is to develop better diagnostic protocols and personalized treatments for patients with OD in aging. However, in order to develop targeted treatments one must first be able to classify patients based on the underlying site of disease and likely mechanism. This hypothesis will be tested using the following Aims: 1) Establish reliable and clinically relevant phenotypes of OD in older adults, 2) Determine the impact of OD on health and quality of life (QOL) in older adults, and 3) Determine which baseline factors predict olfactory changes over time in older adults. The National Institute on Deafness and Other Communication Disorders has a stated its interest in this area, “as the population ages, (to) determine how many more people report…smell problems that affect quality of life.” This proposal will improve our understanding of clinical classifications, mechanisms, QOL impact and natural history of OD in older adults and lay the groundwork for future studies examining therapeutic options to prevent, delay the onset or treat OD in aging.