Distribution characteristics of staghorn calculi bacteria and metabolic differences in patients of different genders.

Objective: The objective of this study was to examine the distribution patterns of bacteria and to elucidate the distinctions in stone composition and metabolism.

Methods: A review of 205 cases of staghorn stones treated at Beijing Tsinghua Changgung Hospital from January 2016 to June 2024 was conducted. Data on preoperative mid-course urine culture, blood biochemistry, 24-hour urine and postoperative stone composition were collected. Stones with > 50% mixed stone components or single components were defined as main stone components. According to the main components, patients with staghorn calculi were divided into infectious and non-infectious stone groups, and the distribution of bacteria among different stone groups was analyzed. The metabolic differences between patients with staghorn calculi of different genders were analyzed according to the results of blood biochemistry and 24-hour urine metabolism.

Results: The study population consisted of 88 males and 117 females with an average age of 53 ± 12 years. The most common components were magnesium ammonium phosphate hexahydrate and carbonated apatite (40%). The prevalence of calcium oxalate stones (16.6%) and uric acid stones (9.3%) was significantly higher in males (P < 0.05), while infectious stones (42.9%) were more prevalent in females (P < 0.05). The detection rate of Proteus mirabilis was more prevalent in the infectious stone group (26.2%), whereas the detection rate of Ureaplasma urealyticum (9%) and Enterococcus faecalis (6.9%) were more prevalent in non-infectious stone group (P<0.05). The levels of serum uric acid, serum creatinine, urinary calcium, urinary sodium, urinary phosphorus, urinary chloride and urinary uric acid were found to be significantly higher in males than in females (P < 0.05).

Conclusion: The biochemical metabolism of patients with staghorn stones exhibits gender-specific differences, with a notable discrepancy in the distribution of bacteria. It is therefore necessary to refine the biochemical metabolic indicators and mid-stream urine culture tests.