To analyze the composition of urinary stones in Taizhou of Zhejiang province.

Clinical data of 1 022 patients with urinary stones admitted in Taizhou Hospital of Zhejiang province were retrospectively reviewed. The samples of urinary stones were collected and analyzed by infrared spectrophotometry.

There were 722 males and 300 females with a male to female ratio of 2.4∶1 and with a mean age of (53.4±13.6) years (14-88 years). Among 1 022 patients, the stones with single composition were found in 299 cases (29.3%); the most common single-component was anhydrous uric acid (15.9%), followed by calcium oxalate monohydrate (12.0%). The mixed stones were found in 723 cases (70.7%); the most common mixture was calcium oxalate monohydrate, calcium oxalate dehydrate and carbonate apatite mixture (316 cases, 30.9%). Calcium oxalate (58.9%, 602/1 022) was the most common major component and frequently seen in upper urinary tract stones, followed by uric acid (21.8%, 223/1 022). Uric acid calculi was predominant component in male patients(χ²=30.97, P=0.00), while the rate of infection stones was higher in women (χ²=60.69, P=0.00). The mean age of patients with uric acid stones was 59.4 years, which was older than that with other components (t=7.62, P=0.00). The uric acid stones were more common in upper urinary tract stones(χ²=42.97, P=0.00). The mean age of patients with infection stones was 49 years, which was younger than that with other types of stones(t=4.87, P=0.00).

Mixed stones with calcium oxalate monohydrate, calcium oxalate dehydrate and carbonate apatite are the predominant urinary stones in Taizhou of Zhejiang province, while the most common single-component stones are anhydrous uric acid stones. Location, age and sex are associated with the types of urinary stones.

Urinary calculi; Stone composition; Spectrum