The relationship between age and fever magnitude

Area of Science:

• Gerontology
• Infectious Diseases
• Clinical Medicine

Background:

• Infections pose significant risks for older adults, often presenting with atypical symptoms.
• Fever, a key infection indicator, is frequently blunted in the elderly, leading to the 'older, the colder' clinical observation.

Purpose of the Study:

• To investigate the impact of age on the febrile response to moderate-to-severe pneumonia.
• To adjust for the influence of temperature measurement site on the observed febrile response.

Main Methods:

• Retrospective cohort study involving 320 hospitalized patients with moderate-to-severe pneumonia.
• Data collected included daily highest temperatures, measurement sites (axillary, oral, rectal), and demographic information, particularly age.
• Linear regression analysis was used to assess the correlation between age and temperature.

Main Results:

• A significant inverse correlation was observed between patient age and temperature on the first two days of hospitalization (P < 0.001).
• Each decade increase in age was associated with a 0.15°C decrease in average temperature during the first three days of infection.
• Temperature at hospital discharge, as a proxy for baseline temperature, also showed a consistent decrease with advancing age.

Conclusions:

• Increasing age is associated with a diminished febrile response to infections.
• Older patients generally exhibit lower baseline body temperatures, complicating infection diagnosis.