Kidney stones and acute kidney injuries caused by trauma, illness, or surgery may predispose patients to end-stage renal disease (ESRD), two new cohort studies suggest.

These findings indicate that close follow-up is important for these patients, researchers said. Lifestyle changes and medication can help slow the progression of chronic kidney disease (CKD) and may reduce the incidence of ESRD.

The first study (J Am Soc Nephrol. E-pub ahead of print. Accessed December 3, 2008). focused on elderly patients aged ≥67 years (median 79.2). Allan J. Collins, MD, of the U.S. Renal Data System in Minneapolis, led a team that used Medicare claims to create a cohort of 233,803 patients who were hospitalized for any reason in 2000. None had a previous history of kidney injury or ESRD before admission.

The incidence of kidney injury at baseline was 3.1%, but almost three quarters of these patients (72.1%) developed CKD within two years. They were also almost seven times more likely to progress to ESRD than patients who had never been injured.

The likelihood of ESRD rose steadily after hospital discharge among patients with a history of injury but no CKD. It was 0.96% within 30 days, 2.69% within 180 days, 4.08% within 365 days, and 6.96% at the end of 2 years of follow-up. The likelihoods for patients without an injury were 0.04%, 0.14%, 0.25%, and 0.49%, respectively.

“Acute kidney injuries have been considered self-limiting, with a good prognosis. These findings suggest that CKD may be unrecognized or that injury can initiate CKD,” which can progress to ESRD, the researchers concluded.

Meanwhile, researchers at the Mayo Clinic in Rochester, Minn., found that people who have had kidney stones are 60% more likely to develop CKD and 40% more likely to progress to ESRD than people who have never formed stones. Patients who have kidney stones plus other CKD risk factors may be at even greater risk for progression, said Mayo investigator John Lieske, MD.

The study was presented at the American Society of Nephrology annual meeting and used data on residents Olmsted County, Minn., between 1984 and 2003.