Prevalence and Correlates of Olfactory Dysfunction in Old Age: A Population-Based Study

Area of Science:

• Gerontology and Neuroscience
• Epidemiology
• Public Health

Background:

• Olfactory dysfunction (OD) in older adults is linked to adverse health outcomes.
• Understanding the factors associated with OD is crucial for identifying underlying mechanisms.
• Interrelationships among OD correlates remain understudied in aging populations.

Purpose of the Study:

• To investigate the prevalence of OD in older adults.
• To examine associations between OD and demographic, genetic, vascular, clinical, and behavioral factors.
• To explore interactions among these factors in relation to OD.

Main Methods:

• Studied odor identification and self-reported olfactory functioning in 2,234 individuals aged 60-90 years (SNAC-K study).
• Defined OD as the inability to identify more than 10 out of 16 odors.
• Utilized multiple logistic regression to analyze associations and interactions.

Main Results:

• OD prevalence was 24.8%; self-reports had low sensitivity (35%) but high specificity (87%).
• Advancing age and coronary heart disease history increased OD probability.
• Female gender and higher education decreased OD probability; APOE ε4 carriers who were obese had elevated OD, while physical activity mitigated cerebrovascular disease impact.

Conclusions:

• Demographic, genetic, and health factors are associated with OD in older adults.
• Behavioral factors like physical activity can modulate OD risk.
• These findings highlight potential targets for OD prevention in aging populations.