New McGill University study sheds light on dehydration

New research from scientists at the Research Institute of the McGill University Health Centre and Duke University advances our understanding of what happens to our bodies when we get thirsty. And the solution isn’t to grab another bottle of Gatorade.

The article, called “DN-TRPV1: A Molecular Co-detector of Body Temperature and Osmotic Stress” was published in the journal Cell Reports. The key finding was the identification of the structure of a key protein in the brain that is involved in body hydration and may control temperature.

“We have identified what we think is the first protein that could allow the brain to monitor physiological temperature and it is important because this protein contributes to how the brain detects heat and triggers adaptive responses such as thirst,” said the study’s lead author, Dr. Charles Bourque, who is a researcher at the Centre for Research in Neuroscience at the RI-MUHC and at the Faculty of Medicine of McGill University.

Bourque says the protein has a wide-ranging affect on how our body handles hydration.

“This protein, which is an ion channel, that regulates the flow of ions across the cell membrane, is thought to play a crucial role in balancing body fluids (water, blood, etc.) and sodium (salts) levels, and changes in its regulation could be involved in linking salt to hypertension, and provoking fluid retention following cardiac failure, sepsis or brain trauma,” adds Bourque.

The researchers say the study is important because body fluid imbalances are a major cause of hospital visits, and understanding the protein could help scientists develop tools to treat various conditions related to dehydration before they end up in an expensive trip to the ER.

In the United States, dehydration is estimated to be the cause of about three-million million visits to the doctor and more than 220,000 hospitalizations each year. And dehydration is responsible for about 10% of all hospital visits by children.

New data suggest hydration may play a bigger role in many health conditions than previously thought. A study of patients admitted to the Comprehensive Stroke Center at Johns Hopkins Hospital in Baltimore, Maryland between July 2013 and April 2014 found that the stroke condition worsened or stayed the same in 42% of dehydrated patients, compared to just 17% of hydrated patients. The study also found that dehydrated stroke patients had an approximately four times higher risk of their conditions worsening than hydrated patients did.

Another study conducted at Loughborough University in England and published in the journal Physiology and Behaviour, says dehydration may be as bad as drinking and driving for those who get behind the wheel. The study separated participants into two groups. One group was given 200 millilitres of water every hour, the other just 25 millilitres. The study found the driving error rate more than doubled for the latter.

“Our findings highlight an unrecognized danger and suggest that drivers should be encouraged to make sure they are properly hydrated,” said Ron Maughan, emeritus professor of sport and exercise nutrition at Loughborough. “The levels of driver errors we found are of a similar magnitude to those found in people with a blood alcohol content of 0.08 per cent.”