The study, conducted by the
researchers from UCLA and the RAND Corp, is based on the analysis of the
National Health and Nutrition Examination Survey (NHANES) data regarding kidney
Scales and his colleagues found that amongst 12,110
responses reviewed, one out of every eleven people had a kidney stone as
compared with one in 20 in 1994. Although the researchers did expect an
increase in the prevalence of kidney stones, 'the size of the increase was
surprising' they said.
The results also showed that in
Men were more likely to report kidney stone disease than
Kidney stones increased with
age in, both, men and women.
Increase in stone disease was
seen particularly in black, non-Hispanic, and Hispanic individuals.
Obesity and diabetes were
strongly associated with a history of kidney stones since kidney stones were
more common in obese than normal-weight people.
According to the lead researcher
Dr. Charles D. Scales Jr., from the Departments of Urology and Medicine,
University of California, USA, 'Our findings suggested that the increase is
due, in large part, to the increase in obesity and diabetes among Americans.'
The link between metabolic syndrome and kidney stones can be explained thus -
obesity increases renal excretion of calcium and uric acid, as well as urine
acidity, and this in turn increases the risk of stone formation.
Dr. Christopher S. Saigal, senior
co-author and principal investigator within RAND Health for the Urologic
Diseases in America project, commented - 'People should consider the increased
risk of kidney stones as another reason to maintain a healthy lifestyle and
body weight'. He also added, 'But physicians need to rethink how to treat and,
more importantly, prevent kidney stones'. The authors noted that, currently,
treatment consisted of surgical intervention rather than management of
metabolic syndrome that leads to recurrence of stones within 5 years in more
than 50 percent of patients.
Dr. Brian Matlaga, associate
professor of urology at Johns Hopkins University School of Medicine, too,
warned that since one-tenth of the American people have kidney stones, greater
emphasis on preventive measures is essential.
The authors concluded - 'This
increase (in the prevalence of kidney stones) is likely related to dietary and
lifestyle factors. Given the temporary disability imposed by a symptomatic
stone event, these findings have important implications for a disease that
burdens a primarily working-age population. These findings suggest that the
direct and indirect costs of kidney stones will continue to rise in the United
States, and efforts should be directed toward ameliorating the burden of
urinary stone disease'.
Scales, C. D., et al. Prevalence of Kidney Stones in the
United States. European Urology, Volume 62, issue 1, pages e1-e30, July 2012