Weight gain and obesity linked to higher risk of kidney stones
Obese women have a 90 percent greater risk of kidney stones; obese men have a 33 percent increased risk
Boston, MA— Kidney stones are one of the most painful conditions to afflict adults and lead to almost two million physician visits each year. Striking 10 percent of men and five percent of women, kidney stones cost the United States healthcare system approximately $2 billion annually. Now, researchers from Brigham and Women’s Hospital (BWH) have found that obesity and weight gain are both associated with a significant increase in the risk of developing kidney stones. The findings are published in the January 26, 2004 issue of the Journal of the American Medical Association.
“Our study demonstrated that multiple measures of larger body size, including larger waist circumference, higher weight, and higher body mass index, were related to an elevated risk of kidney stones,” said Eric Taylor, MD, a BWH researcher and nephrologist. “In addition, weight gain over time was associated with an increased risk of stones. These new findings provide the latest evidence that maintaining a healthy weight should be encouraged.”
The data is based on a study of approximately 45,000 men and more than 200,000 women enrolled in the Health Professionals Follow-up Study and the Nurses’ Health Studies who were followed for up to 20 years.
The researchers, who accounted for difference in diet, fluid intake, and medications in the study participants, report the following evidence linking measures of larger body size to kidney stone risk:
· Women in the highest weight category had an 89 percent greater risk of kidney stones compared to those in the lowest weight category. Men had a 44 percent greater risk.
· Women who were obese had a 90 percent greater risk of kidney stones compared to women in a lower category of body mass index (BMI).
· Men who were obese had a 33 percent greater risk of kidney stones compared to men in a lower category of BMI.
· Women with the largest waist circumferences had a 71 percent greater risk of kidney stones compared to those with the lowest waist circumferences. Men had a 48 percent greater risk.
· Men who gained more than 35 pounds since age 21 had a 39 percent greater risk of kidney stones.
· Women who gained more than 35 pounds since age 18 had a 70 percent greater risk of kidney stones.
“Obesity and weight gain appear to increase the risk of kidney stones. Fat tissue may decrease the body’s ability to respond to insulin, which could cause changes to the urine that favor the growth of kidney stones, but more research needs to be done to confirm this hypothesis,” said Taylor, who is also an instructor in Medicine at Harvard Medical School. “Additionally, because our study found such a dramatic link between weight gain and kidney stones, the next step is to see if weight loss provides an effective strategy to decrease kidney stone recurrence.”
Please contact BWH Media Relations for more information at (617) 534-1600 or BWHMediaRelations@partners.org.
BWH is a 747-bed nonprofit teaching affiliate of Harvard Medical School and a founding member of Partners HealthCare System, an integrated health care delivery network. BWH is committed to excellence in patient care with expertise in virtually every specialty of medicine and surgery. The BWH medical preeminence dates back to 1832 and today that rich history in clinical care is coupled with its national leadership in quality improvement and patient safety initiatives, dedication to educating and training health care professionals, and strength in biomedical research. With $370M in funding and more than 500 research scientists, BWH is an acclaimed leader in clinical, basic and epidemiological investigation - including the landmark Nurses Health Study, Physicians Health Studies, and the Women's Health Initiative. For more information visit www.brighamandwomens.org
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