‘Smart’ water bottle may help with stone prevention

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Despite the excruciating nature of kidney stones, many people can't manage to lower their risk by simply drinking more liquid. Now, a new study finds that one potential tool-a water bottle with a built-in consumption sensor and smartphone link-accurately tracks how much people drink.

Dr. Borofsky"This opens doors to use this not only as a tool that might benefit our patients but also as a research instrument," said study co-author Michael S. Borofsky, MD, who's begun using the water bottle himself to boost his own hydration.

At issue: The perennial inability of many people, including veterans of kidney stones, to increase fluid intake in their daily lives.

Research suggests that water consumption is an inexpensive, easy, and generally safe way to reduce kidney stones. A 2016 meta-analysis linked high fluid consumption to much lower rates of incident kidney stones and recurrent kidney stones than in people with inadequate fluid intake, with risks falling by as much as 59%. However, the amount of liquid needed to make a difference may be hefty: The report suggests that 2.9 liters per day or more may be needed to show a preventive effect (JNephrol 2016; 29: 211–9).

The Hidrate Spark water bottle can sync with smartphones and some other devices, track water intake, and be programmed to glow when it's time to take a drink. (Images courtesty of Hidrate Inc.)

Kidney stone patients often fail to drink enough fluid despite encouragement from urologists, said Dr. Borofsky, assistant professor of urology at the University of Minnesota, Minneapolis, who started the study while at Indiana University.

"Most commonly, I would say it seems to be a lifestyle issue. Some people don't like the taste of water or feel like they're going to the bathroom too much. But most of the time, people don't realize how much they're supposed to be drinking, or they just forget,” he said.

The new study, which was presented at the 2016 World Congress of Endourology in Cape Town, South Africa, was born when Dr. Borofsky heard about the Hidrate Spark, a "smart" water bottle developed by a Boulder, CO company. The $54.95 bottles, which sync with smartphones and some other devices, track water intake and can be programmed to glow when it's time to take a drink.

"The bottle automatically takes measurements and saves them, updating your smartphone periodically when it's nearby. When you drink the bottle to completion, it registers zero and resets itself when you refill it,” Dr. Borofsky said.

Dr. Borofsky and his co-authors hope to test the water bottles in stone formers, but first they decided to test its accuracy. For the study, they received free 24-ounce sample bottles from Hidrate Inc., the Hidrate Spark manufacturer, and recruited eight subjects to drink out of the bottles for 24-hour periods.

The subjects, who took part in the experiment for 62 24-hour periods, hand-measured the liquid they consumed in order to validate whether the bottles provided accurate numbers.

Next: Bottle's measurements 'very accurate'

Bottle’s measurements ‘very accurate’

The authors found that the bottles underestimated actual liquid consumption by a mean of 0.5 oz (95% CI: 1.9, 0.9); the mean 24-hour measurement was 57.2 oz (21-96).

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"We found out that it was very accurate," Dr. Borofsky said. The bottles’ high reliability raises the prospect that the bottles could become more than a hydration aid. They could also serve as a research tool since they could provide more reliable details about the liquid intake of subjects than questionnaires, he said.

What's next?

"We're currently working on a multicenter study and will be enrolling patients shortly. We'll try to implement the water bottle for patients with a recognized fluid deficiency who are forming kidney stones. We'll see if the smart water bottle increases urine output compared to standard of care,” Dr. Borofsky said.

As for now, Dr. Borofsky says he's been using the smart water bottle himself.

"I'm certain that I'm not meeting the recommended hydration goals. It’s encouraged me to be more aware of how much I'm drinking and influenced me to be a little more proactive about staying hydrated,” he said.

Hidrate Inc. provided free smart water bottles for the study.