Olfactory Decline in Elderly at High Altitudes: A Narrative Review

Area of Science:

• Gerontology
• Environmental Medicine
• Neuroscience

Background:

• Olfactory dysfunction is common in the elderly, impacting quality of life and signaling neurodegenerative diseases.
• High-altitude environments (hypoxia, cold, low humidity) may exacerbate olfactory decline in older adults.
• Existing research on high-altitude olfactory dysfunction is fragmented, necessitating a systematic review.

Purpose of the Study:

• To systematically review epidemiological data, pathophysiological mechanisms, diagnostic tools, interventions, and health risks of olfactory decline in elderly high-altitude residents.
• To elucidate the combined effects of high-altitude stress and aging on the olfactory system.
• To identify unique patterns and intervention targets for this population.

Main Methods:

• Narrative review integrating existing epidemiological, mechanistic, and clinical evidence.
• Analysis of studies correlating altitude with olfactory function.
• Synthesis of research on hypoxia, aging, and olfactory system changes.

Main Results:

• A significant negative correlation exists between altitude and olfactory function, with aging effects amplified at high altitudes.
• Mechanisms include chronic hypoxia interacting with aging, damaging olfactory cells, suppressing neurogenesis, and altering brain plasticity.
• Olfactory testing, fMRI, and biomarkers offer diagnostic potential, but evidence for interventions like oxygen therapy and olfactory training is limited in this group.

Conclusions:

• High-altitude living significantly worsens age-related olfactory decline through complex environmental-aging interactions.
• Targeted interventions and altitude-specific diagnostic tools are needed.
• Future research should focus on longitudinal studies and precision medicine for hypoxic injury.