Study tests methods to prevent kidney stone recurrence

Dr. Naim Maalouf, left, Dr. Jodi Antonelli, Dr. Yair Lotan, and Dr. Linda Baker will lead the UT Southwestern arm of a study to identify the best options for preventing kidney stones.
Dr. Naim Maalouf, left, Dr. Jodi Antonelli, Dr. Yair Lotan, and Dr. Linda Baker will lead the UT Southwestern arm of a study to identify the best options for preventing kidney stones.

DALLAS – Sept. 13, 2017 – A national clinical trial at UT Southwestern Medical Center will test the best methods to encourage people to drink water to reduce the recurrence of kidney stones.

The Prevention of Urinary Stones with Hydration (PUSH) study is part of a large-scale, multi-center series of studies, which combined are expected to be among the largest kidney stone studies ever conducted. The studies seek answers to how to prevent kidney stones and reduce pain associated with treatments.

“While our understanding of the mechanisms leading to kidney stone formation has greatly improved in the last 30 years, we have not been able to effectively reduce the stone recurrence rate in many patients. And stent-related pain remains a significant problem for patients and doctors. If we can better understand the underlying causes, then we can treat it better,” said Dr. Naim Maalouf, Associate Professor of Internal Medicine at UT Southwestern and the principal investigator at UT Southwestern.

The PUSH study

Urinary Stone Disease Research Network logo

The first of the group of kidney stone studies to get underway is the Prevention of Urinary Stones with Hydration, or PUSH study, which begins enrolling participants in mid-September.

How to join:

Prevention of Urinary Stones with Hydration (PUSH) will enroll about 1,600 people, half in the intervention group and half in the control group.

Who can enroll:

  • Must be at least 12 years old
  • Have had at least 1 symptomatic stone in the past 3 years
  • Meet other eligibility criteria

How to enroll:

  • Adults can call 214-645-8787
  • Parents of adolescents can call 214-456-0279

For more information:

Five medical centers, including UT Southwestern Medical Center, will participate in the studies by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health (NIH), funded through grant DK110986.

Participants include both adolescents and adults who previously had kidney stones.

“Drinking more water helps to prevent kidney stone recurrence by diluting the urine, and making minerals more soluble in urine. However, increasing fluid intake and maintaining a high urine volume on a daily basis is challenging in both children and adults,” Dr. Maalouf said.

“Barriers to drinking water vary. Some patients may not like the taste of water. Some, such as teachers and drivers, may be in occupations that limit bathroom breaks. Some may simply forget. We will use a combination of interventions including direct counseling, smart water bottle and smart phone technology, and financial rewards, to help individual patients consume more water,” said Dr. Maalouf, who holds The Frederic C. Bartter Professorship in Vitamin D Research and is with the division of Mineral Metabolism.

The program will include modest financial incentives and individualized coaching over the two-year course of the study.

Kidney stones tend to be a recurring problem, with nearly 50 percent of people who had a kidney stone experiencing a second stone, according to the American Urological Association. The water trial will follow participants for two years, comparing recurrence rates in those who are prompted to drink more fluids with a control group who receive routine clinical care.

The second clinical trial will look at pain associated with stents, which are hollow plastic tubes that are temporarily inserted in the ureter following stone removal to facilitate urination and passage of stone fragments. The ureter is a duct through which urine passes from the kidney to the bladder.

Not all patients experience pain from stents, and among those who do, the degree of discomfort can vary greatly. The stent study will identify factors that predict which patients are likely to experience stent pain, and then intervene, with various treatments.

Stents pain can be particularly problematic for pediatric patients, whose ureters can be so small that they may need to have a stent inserted prior to surgery to empty the kidneys and then a second stent following stone removal.

Kidney stones are common. In the United States, 9 percent of the population has had a stone, according to NIDDK. Men are more likely to experience a kidney stone than women, though this gender gap is closing. Kidney stones are also increasing in children.  

About kidney stones disease

Three kidney stones
  • Urinary Stone Disease (USD) affects about 1 out of 11 Americans
  • People who have one stone are more likely to have another
  • The number of people in the US with USD has nearly doubled in the last 15 years
  • The annual cost of USD is estimated at $10 billion, making it the most expensive nonmalignant urologic condition in the U.S.

“There are multiple factors that we think are contributing to the increase in stones among kids. For many children who form stones, there’s a genetic component,” said Dr. Linda Baker, Professor of Urology and in the Eugene McDermott Center for Human Growth and Development at UT Southwestern.

“But it’s also about diet. Salt – sodium – consumption is increasing heavily in our diets. A lot of the junk foods that kids eat are heavily salted. And then, instead of drinking water, more people drink sodas. That’s a source of oxalate. High salt plus high oxalate equals calcium oxalate stones,” said Dr. Baker, who will work with pediatric patients who participate in the trials. 

Other UT Southwestern investigators who will participate in the studies include Dr. Jodi Antonelli, Assistant Professor of Urology; Dr. Margaret Pearle, Professor of Urology and Internal Medicine, and holder of the Dr. Ralph C. Smith Distinguished Chair in Urologic Education; Dr. Yair Lotan, Professor of Urology and holder of the Helen J. and Robert R. Strauss Professorship in Urology;  Dr Khashayar Sakhaee, Professor of Internal Medicine and holder of the Laura Kim Pak Professorship in Mineral Metabolism Research and the BeautiControl Cosmetics Inc. Professorship in Mineral Metabolism and Osteoporosis; Dr. Orson Moe, Professor of Internal Medicine and Physiology;  Dr. Marlyn Allicock, Adjunct Assistant Professor of Clinical Sciences; and Dr. Lakshmi Ananthakrishnan, Assistant Professor of Radiology.      

The UT Southwestern studies are funded by a $3.5 million grant from the NIH and the NIDDK. Other participating medical centers are Duke University; University of Washington in Seattle; University of Pennsylvania and Children’s Hospital of Philadelphia; and Washington University in St. Louis.

About UT Southwestern Medical Center

UT Southwestern, one of the premier academic medical centers in the nation, integrates pioneering biomedical research with exceptional clinical care and education. The institution’s faculty includes many distinguished members, including six who have been awarded Nobel Prizes since 1985. The faculty of almost 2,800 is responsible for groundbreaking medical advances and is committed to translating science-driven research quickly to new clinical treatments. UT Southwestern physicians provide medical care in about 80 specialties to more than 100,000 hospitalized patients and oversee approximately 2.2 million outpatient visits a year.


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