The effect of selenium supplementation on cystine crystal volume in patients with cystinuria

Background: Cystinuria as an autosomal recessive sickness is a relatively rare disease. Formation of cystine stones indicates cystinuria. Few studies are considered the cysteine crystal volume in management of cystinuria. Selenium may inhibit organization of crystal stone, growth and stone aggregation. Since the role of selenium on inhibition of cystine crystal formation is not known, the aim of this study was to evaluate the effect of selenium supplementation on cystine crystals volume in patients with cystinuria. Materials and methods: This double-blind clinical trial study was conducted on 48 patients in Al-Zahra hospital, Isfahan, Iran from 2015 to 2017. These patients received selenium (200 mg/ daily) for 6 weeks. The urine crystal volume was evaluated before and after treatment. Data were entered SPSS and analyzed by Paired sample T test, Spearman and Pearson coefficient correlation. P- value < 0.05 was considered significant. Results: In current study, mean cystine crystal volume before and after treatment was 6787.4 ± 11902.6 and 3110.9 ± 7225.4, respectively. Significant difference was observed before and after treatment in terms of cystine crystal volume (p < 0.001). No relation was observed between the mean cystine crystal volume with sex, age and type of medical procedures (p > 0.05). Conclusion: In this study, selenium treatment affected cystine crystal volume. It seems that selenium had the potential value to alleviate the volume of cystine crystal. Therefore, since reducing of cystine crystal volume decreases crystal formation, selenium may be effective to cure patients with cystinuria. However, age, sex and type of medical procedures did not affect cysteine crystal volume.