U of A Research Suggests Drinking Water Affects Glucose Regulation

University Relations

U of A graduate student Lisa Jansen, left, a co-author of a new research paper on glucose regulation, demonstrates blood collection for a glucose tolerance test.

If you have Type 2 diabetes, does the amount of water you drink affect the way your body regulates glucose?

That's the research question that faculty and students in Hydration Science Lab at the University of Arkansas explored for a paper recently published by the Nutrition Research journal. The lab, directed by Stavros Kavouras, a professor of exercise science, conducts research into many aspects of hydration and its effect on health and performance.

The project described in Nutrition Research suggested the answer was yes, water intake does affect glucose regulation. The bottom line was that hydration status should be considered when patients with Type 2 diabetes take oral glucose tolerance tests, the researchers said.

"What is interesting is that the majority of people do not meet the dietary guidelines for water both in the United States and around the world," Kavouras said. "Data from American kids indicate that most of them are underhydrated while one in every four do not drink plain water. It would be interesting to see how this behavior could influence their ability to regulate glucose."

Nine men between the ages of 44 and 62 who had previously been diagnosed with Type 2 diabetes and were considered sedentary completed the study. Type 2 diabetes can develop at any age but most commonly becomes apparent during adulthood. People with Type 2 diabetes cannot use insulin effectively. Type 1 diabetes is less common and was formerly called juvenile-onset diabetes. People with Type 1 diabetes either completely lack insulin or have too little of it. Insulin is a hormone that helps the body's cells use sugar, or glucose, for energy.

Each man came to the Hydration Science Lab facilities in the HPER building to take two identical two-hour oral glucose tolerance tests in which they drank a glucose substance before their blood was drawn for analysis. They took one test after drinking an amount of water sufficient for their bodies to be considered euhydrated, which means having normal body water content. They took the other test after drinking a smaller amount of water that would cause their bodies to be considered hypohydrated, which is another term for dehydrated or not having enough water in the body to carry out its normal functions.

Following each test, researchers collected blood from the men and analyzed it.

Their findings suggested that three days of low water intake in people with Type 2 diabetes acutely impairs blood glucose response during an oral glucose tolerance test. More specifically, the impairment was found to be related to stress hormones produced along the hypothalamic-pituitary axis that regulates many body processes. It was found not to be related to hormones produced in the renin-angiotensin-aldosterone system that regulates blood components and pressure.

The article being published in the July issue of Nutrition Research is co-authored by Evan Johnson, Costas Bardis, Lisa Jansen, J.D. Adams, Tracie Kirkland and Kavouras. It explained that only men were recruited because of the influence of menstrual cycle hormones on total body fluid balance. The researchers plan to include both genders in future projects so that findings will be applicable to both men and women.