Not drinking enough water is a common but under-recognized problem among American seniors that puts their health at risk, researchers say.
"So many health issues are related to inadequate hydration," including urinary tract and respiratory infections, frequent falls and other problems, said study author Janet Mentes. She's a professor of nursing at the University of California, Los Angeles (UCLA).
One problem in determining seniors' hydration levels is a lack of a gold standard of assessment. In this study, the researchers investigated whether a method called salivary osmolality could be used to check hydration levels in older adults.
Salivary osmolality compares the ratio of water to certain chemicals that occur naturally in saliva. It can be measured using a simple, noninvasive device called an osmometer.
The study of 53 people, aged 65 or older, in Los Angeles found that, overall, seniors had higher osmolality (that is, greater dehydration) than younger adults. Seniors' dehydration was higher in the morning than the afternoon, and it was a bigger problem for those with limited mobility, the findings showed.
Interviews with participants pointed to a major reason for higher osmolality in the morning: Many avoid drinking water so they won't have to urinate during the night.
The study was recently published online in the journal SAGE Open Nursing.
"Many seniors are underhydrated for a period of time, and when they are exposed to a virus or bacteria they are more likely to develop an infection, such as urinary tract infections, pneumonia or other respiratory diseases," Mentes said in a UCLA news release.
"And they will be treated for the infection, but the underlying underhydration will not be recognized," she added. "Thus, an opportunity to educate the individual about adequate fluid intake is missed."
Up to 40 percent of older people who live in the community may be chronically underhydrated, the researchers said.
Dehydration accounted for a 5 percent increase in preventable emergency department visits between 2008 and 2012, and adults older than 65 have the highest hospital admission rates for dehydration, according to the U.S. Agency for Healthcare Research and Quality.
The U.S. National Institute on Aging has more about hydration.