Chemical components of urinary stones according to age and sex of adult patients.

OBJECTIVE Report the relationship of composition with age and sex of the patients. MATERIAL AND METHOD A series of 426 urinary stones, 33 from the lower (LUT) and 393 from the upper urinary tract (UUT) of adults, were analyzed for their chemical composition using infrared spectroscopy. The majority of LUT stones were from males (n = 26) and in the age group beyond 60 years (n = 20). RESULTS Calcium oxalate (CaOx) and uric acid and urate (UA-UR) were the main constituents in LUT stones of males and UA-UR and magnesium ammonium phosphate (MAP) of females. While UA-UR was distributed in all age group of males, it was only detected in elderly females. In cases of UUT stones, the peak finding for both sexes was for the 50-59-year-olds (age class). The MAP component was found more commonly in UUT stones of females, particularly in the younger age groups. CaOx and calcium phosphate (CaP) were the main components of UUT stones in both sexes (CaP was slightly more common in females) with the highest proportion in the 30-49-year-olds (age class), thereafter they declined and were replaced with UA-UR. CONCLUSION Although the proportion of LUT stones in the present study was small, the present findings agree with previous studies on the role of both age and sex in the etiopathogeny of urinary stones.