The development of the predisposition to dehydration questionnaire

Area of Science:

• Physiology
• Public Health
• Psychology

Background:

• Hydration is crucial for health, yet population-level monitoring tools are scarce.
• Understanding individual responses to heat stress is vital for public health.
• Dehydration can impact cognitive function and mood.

Purpose of the Study:

• To develop and validate a questionnaire assessing individual differences in dehydration tendency.
• To investigate the relationship between self-reported hydration habits and physiological responses to heat.
• To explore the impact of heat exposure on mood and cognitive function in relation to hydration status.

Main Methods:

• Fifty-three subjects underwent a four-hour heat exposure (30°C).
• Physiological measures (body mass, urine osmolality) and mood assessments were recorded.
• Questionnaires captured habitual fluid intake and perceived heat response.

Main Results:

• Significant individual variations in body mass loss (0.24%-2.39%) were observed.
• Higher habitual fluid intake correlated with lower baseline urine osmolality and increased urine production post-heat exposure.
• Females reporting poor heat response experienced increased confusion, uncertainty, and depression.
• In males, higher habitual intake and poor heat response were linked to increased drinking.

Conclusions:

• Questionnaire-based assessments can predict hydration changes in warm environments, particularly in females.
• Individual hydration habits and perceived heat response are significant factors in heat tolerance.
• The findings highlight the need for personalized hydration strategies for public health.