Drinking More Water Reduces Repeat Urinary Tract Infections

Marcia Frellick

October 09, 2017

SAN DIEGO — Premenopausal women prone to urinary tract infections who drink less than 1.5 liters (about 6.25 cups) of water daily can halve the number of repeat infections they experience by increasing their intake of water by approximately 6 cups, a new randomized controlled study suggests.

It is likely that the number of infections decreases because frequent flushing means that the bacteria don't have time to attach in the bladder and that the concentration of bacteria is diminished, said Thomas Hooton, MD, clinical director of the division of infectious diseases at the University of Miami School of Medicine.

The 6-cup level was the only increase tested, he reported during a press conference here at IDWeek 2017.

Although only water was tested, other fluids would likely have the same result, Dr Hooton told Medscape Medical News. However, water has the benefit of adding no cost or calories, he explained.

He also suggested that the results would probably be the same in postmenopausal women.

Dr Hooton and his colleagues asessed 140 healthy premenopausal women who had experienced at least three urinary tract infections in the previous year and self-reported daily fluid intake below 1.5 liters. The 70 women in the intervention group were instructed to drink an additional 1.5 liters each day, whereas the 70 in the control group were instructed not to change their usual intake.

During the 1-year study period, the researchers followed the women with in-person visits and phone calls.

The average daily increase was 1.15 liters (about 5 cups) in the intervention group, for a daily total of 2.8 liters (12 cups). The average daily intake was 1.2 liters (5 cups) in the control group.

At 1 year, there were 48% fewer urinary tract infections in the intervention group than in the control group (1.6 vs 3.1; odds ratio, 0.52; 95% confidence interval, 0.46 - 0.60; < .0001).

In addition, the number of days to the first recurrent episode of acute uncomplicated cystitis was longer in the intervention group than in the control group (148 vs 93;= .0005), as was the average number of days between episodes (143 vs. 85; < .0001).

Fewer Infections, Fewer Antibiotics

There were 47% fewer courses of antibiotics in the intervention group than in the control group (1.8 vs 3.5; < .0001).

This reduction could have a worldwide impact, given the prevalence of urinary tract infections and the global increase in antibiotic resistance, Dr Hooten said.

Up to 60% of women will develop a urinary tract infection in their lifetime, and one in four women will have a repeat infection, according to the National Institute of Diabetes and Digestive and Kidney Diseases. And urinary tract infections lead to more than 10 million doctor visits a year, the National Kidney Foundation reports.

It makes intuitive sense and it validates a lot of the things we already do.

It is good to have a prospective trial backing a recommendation that can help such a common problem, said Sovrin Shah, MD, assistant professor of urology at the Icahn School of Medicine at Mount Sinai in New York City.

He said he sees three to five new patients a day with recurring urinary tract infections.

"As far as I know, I don't think we've had a really good trial that shows that this is helpful," he told Medscape Medical News. "It makes intuitive sense and it validates a lot of the things we already do."

Not a Solution for Everyone

But this easy solution might not work for everyone. For women with overactive bladder, increased water intake could exacerbate the urgency to urinate and increase urinary incontinence, Dr Hooton explained.

"The women in the study were very compliant, in general, but no doubt some women will be resistant," he said. However, "women with recurrent urinary tract infections are often highly motivated to try things," and many would find this approach "more attractive than taking antibiotics."

The study is supported by Danone Nutricia Research. Dr Hooton reports consulting for or serving on advisory boards for GSK, Achaogen, Ocean Spray, and Paratek; receiving travel reimbursement from Danone when he helped plan this study; and being a cofounder of Fimbrion Therapeutics, a start-up biotech company that is developing antimicrobial-sparing approaches to prevent urinary tract infections. Dr Shah disclosed no relevant financial relationships..

IDWeek 2017: Abstract LB-7. Presented October 5, 2017.

Follow Medscape on Twitter @Medscape and Marcia Frellick @mfrellick


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