Increased serum creatinine associated with testicular microlithiasis in adult Japanese men: A retrospective cohort study.

Background: Testicular microlithiasis (TM) is thought to be associated with testicular tumors and impaired spermatogenesis; however, its etiology remains unclear.
Objectives: To identify factors, other than testicular function, that are associated with testicular microlithiasis.
Materials and Methods: We enrolled males who underwent ultrasound examination of the scrotum at Tokyo Dental College Ichikawa General Hospital. The patients were categorized into two groups: those with or those without testicular microlithiasis. Background and blood test data were compared between the groups.
Results: Testicular microlithiasis was observed in 72 of the 828 (8.7%) patients enrolled. Ages ranged from 15 to 87 years (mean age, 40.0 years). A history of germ cell tumor was significantly more prevalent in patients with testicular microlithiasis than in those without (1.3 vs. 16.7%; p < 0.001). Blood test data showed that, patients with testicular microlithiasis had significantly higher serum creatinine levels (0.91 vs. 1.04 mg/dL; p = 0.046) and lower calcium levels (9.4 vs. 9.3 mg/dL; p = 0.031) than those without. Serum creatinine levels (> 1.00 mg/dL) and germ cell tumors were significantly associated with testicular microlithiasis in both univariate and multivariate analyses. The prevalence of testicular microlithiasis increased in patients older than 50 years. Age (> 50 years) was associated with testicular microlithiasis in univariate analysis. The mean body weight tended to be heavier (70.7 vs. 72.2 kg; p = 0.051) and epididymitis was observed more frequently (3.2 vs. 8.3%; p = 0.056) in patients with testicular microlithiasis than in those without.
Discussion and Conclusion: A history of testicular tumors and elevated serum creatinine levels were associated with testicular microlithiasis. Testicular microlithiasis was observed across all age groups, with a tendency to increase in patients older than 50 years. Patients with testicular microlithiasis were slightly heavier and had a higher prevalence of epididymitis than those without. Our findings suggest that, in addition to testicular dysgenesis, other factors are involved in the development of testicular microlithiasis.
(© 2023 American Society of Andrology and European Academy of Andrology.)