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Testosterone therapy tied to kidney stone risk



Testosterone replacement therapy was associated with heightened risk for kidney stones, according to an analysis of more than 50,000 men with low testosterone.

When researchers compared hypogonadal men to age- and comorbidity-matched controls, they found a statistically significantly higher number of clinical diagnoses of a kidney stone, or of patients undergoing a kidney stone–related procedure.

Dr. Tyler McClintock, urology resident at Brigham and Women's Hospital, Boston Jim Kling/MDedge News

Dr. Tyler McClintock

Animal studies have suggested that testosterone replacement can increase oxalate and decrease citrate levels in the kidney, both of which may increase risk of stone formation.

The new study is the first large-scale analysis of the question in humans, according to Tyler McClintock, MD, who presented the findings at a poster session at the annual meeting of the American Urological Association. Dr. McClintock is a urology resident at Brigham and Women’s Hospital and Harvard Medical School in Boston.

Dr. McClintock and his colleagues analyzed data from the Military Health System Data Repository (MDR). The MDR includes beneficiaries of the TRICARE program for service members, retirees, and their families. They looked at 26,586 men aged 40-64 years who had been diagnosed with low testosterone and who had received continuous testosterone replacement therapy between April 2006 and March 2014. The researchers compared them to 26,586 controls with low testosterone who did not receive testosterone replacement therapy.

Stone events were significantly higher in the treatment group. There were 67 extracorporeal shock wave lithotripsy procedures in the treatment group, compared with 51 among controls. Similar trends were seen with ureteroscopy with lithotripsy (75 vs. 46) and clinical diagnoses of kidney stone (1,059 vs. 794).

The researchers also broke down stone events by type of testosterone replacement therapy. A total of 5.4% of patients who received pellets (9 of 167) experienced an event (P = .27), compared with 5.1% of those who received injections (218 of 4,259; P = .004) and 3.5% of those who received it topically (655 of 18,895; P less than .0001).

At 2 years, Dr. McClintock reported that there were significantly more kidney stone events in the testosterone-treated group than in the untreated group (659 and 482, respectively; P less than .001). Two years after starting testosterone replacement therapy, significantly more of the treatment group had experienced a stone episode, compared with the matched controls during the same time period (3.9% and 3%, respectively; P less than .001).

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