Body Water Dehydration, Water Stress
Conditions
Keywords
Vasopressin, Heart Rate Variability, Cardiovascular Function, Autonomic Function
Brief summary
The regulation of total body water that defines human hydration status is a complex and dynamic process. Current methods of assessing hydration status (e.g. hematologic and urinary analyses) lack the ability to track changes in hydration status in real-time due to whole-body homeostatic physiologic processes required to maintain central pressure and cardiovascular function. This project will address this problem by assessing the relationship between autonomic function (measured using heart rate variability), a brain-derived process that regulates cardiovascular function, and changes in the hydration-mediated hormone vasopressin.
Interventions
OTHERHypertonic Saline
Infusion of hypertonic saline to induce an osmotic secretion of the hormone vasopressin
OTHERNormal Saline
Infusion of normal saline to inhibit the secretion of the hormone vasopressin
Sponsors
University of North Carolina, Greensboro
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
NONE
Intervention model description
Participants will complete two trials under two different hydration states: isovolemic increase in plasma osmolality and isovolemic control (maintain normal plasma osmolality)
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Males and Females between the ages of 18 - 35
Exclusion criteria
* 1\) evidence of clinically relevant diseases that may alter body water regulation (e.g., diabetes, kidney disease, metabolic disorders, cardiovascular disease, and other potential fluid balance covariates such as habitual use of non-steroidal anti-inflammatory drugs or serotonin reuptake inhibitors, 2\) previous surgery on the digestive tract that may impair the body's ability to normally regulate body water, 3\) regular drug treatment within the previous 15 days, 4\) actively attempting to gain or lose body weight, 5\) For female participants, testing will take place during the early follicular phase of their menstrual cycle (days 1-8) to maintain consistency in the hydration status measures as total body water fluctuates over the course of the menstrual cycle. Females who are currently using contraceptives (e.g., IUD) that limit the number of menstrual cycles occurring in a given year will be excluded from this study to ensure accuracy in the testing periods for this study.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in autonomic function | 0, 15, 30, 45, 60, 75, 90, 105, 120 minutes of saline infusion period | Changes in parasympathetic and sympathetic tone as measured by heart rate variability |
Countries
United States
Outcome results
None listed