Update: Exertional hyponatremia, active component, U.S. Armed Forces, 2006-2021.

Area of Science:

• Military Medicine
• Environmental Health
• Sports Medicine

Background:

• Exertional hyponatremia is a serious condition linked to excessive water intake during physical activity.
• Understanding incidence trends and risk factors is crucial for prevention in active populations.

Purpose of the Study:

• To analyze the incidence and trends of exertional hyponatremia among active component service members from 2006 to 2021.
• To identify demographic and military-specific risk factors associated with exertional hyponatremia.

Main Methods:

• Retrospective analysis of incident diagnoses of exertional hyponatremia.
• Surveillance data from active component service members between 2006 and 2021.
• Calculation of crude incidence rates per 100,000 person-years.

Main Results:

• A total of 1,669 diagnoses were recorded, with an overall incidence rate of 7.8 per 100,000 person-years.
• Higher incidence rates were found in female, younger (<20 years), and recruit service members.
• Incidence varied by military branch (highest in Marine Corps) and ethnicity (highest in non-Hispanic White service members).
• Rates peaked in 2010, decreased by 2013, and fluctuated thereafter, with a notable increase in 2020.

Conclusions:

• Exertional hyponatremia poses a significant risk to active service members, particularly specific demographic groups.
• Awareness of excessive water consumption dangers and intake limits is essential for service members and leaders.
• Targeted prevention strategies may be needed for high-risk populations and during periods of increased incidence.