Older Stone Patients May Present Atypically, Study Shows
The clinical presentation of kidney stones differs by age, a study shows. Older individuals, for example, are less likely to have renal colic and more likely to have non-calcium stones compared with younger patients.
A team led by Amy E. Krambeck, MD, of Mayo Clinic in Rochester, studied 753 residents of Olmstead County, Minnesota, who had validated incident kidney stones. Subjects had a mean age of 44 years (range 7 months to 96 years).
At presentation, 83% had renal colic, 12% had atypical pain, and 6% had no pain. The mean age of patients with these presentations varied significantly (43, 47, and 51 years, respectively) Dr. Krambeck reported at the World Congress of Endourology in Chicago. In addition, the 7% of patients who presented with urinary tract infections were significantly older than those who did not (55 vs. 42 years). A total of 259 patients (34%) underwent surgery, and they were significantly older than those who did not (48 vs. 41 years, respectively). Each decade of life increase was associated with a 1.3-fold increased risk of requiring surgery. More specifically, those patients who were over age 60 years were 2.5 times more likely to require surgery and 3.9 times more likely to present with a urinary tract infection than those patients younger than 60.
Furthermore, of the 458 patients who had their stones' composition analyzed, the primary component was calcium oxalate monohydrate (64%), hydroxyapatite (18%), calcium oxalate dehydrate (12%), uric acid (4%), and other components (2%). The mean ages of patients with these types of stones were 45, 37, 38, 59, and 49 years, respectively.
“Due to the atypical presentation, a higher index of suspicion may be needed to diagnose urolithiasis in the aging population,” Dr. Krambeck's group concluded.