Delirium and the dexamethasone suppression test in the elderly

Area of Science:

• Geriatric Medicine
• Endocrinology
• Neuroscience

Background:

• Delirium in the elderly is potentially linked to high glucocorticoid levels or increased sensitivity.
• Understanding the endocrine basis of delirium is crucial for geriatric care.

Purpose of the Study:

• To investigate the relationship between dexamethasone suppression test (DST) results and the incidence of delirium in elderly patients with acute lower respiratory tract infections.
• To explore whether impaired cortisol suppression is a risk factor for delirium in this population.

Main Methods:

• A dexamethasone suppression test (DST) was administered to 16 elderly patients admitted for lower respiratory tract infection.
• Patients were monitored for the development of delirium during their hospital stay.
• DST results were analyzed in relation to delirium occurrence and clinical severity indicators.

Main Results:

• A significantly higher proportion of patients who developed delirium were non-suppressors on the DST (78%) compared to those without delirium (14%) (p=0.04).
• No significant differences in clinical or laboratory indicators of illness severity were observed between the groups.
• Abnormal DST results persisted in most non-suppressors even after delirium and infection resolution.

Conclusions:

• Impaired cortisol suppression, as indicated by an abnormal DST, may be a significant risk factor for delirium in elderly patients with acute illness.
• These findings suggest a potential role for glucocorticoid dysregulation in the pathophysiology of delirium in older adults.
• Identifying non-suppressors could aid in predicting and potentially preventing delirium in vulnerable elderly patients.