Statistical analysis of amino acidcomposition of uroliths in residents of the Komi Republic

The purpose of the paper was to identify, by statistical analysis, differences in the amino acid composition of uroliths in residents of the Komi Republic. Onedimensional (Kruskel Wallis and Mann Whitney criteria, unpaired Student’s t test) and multidimensional (discriminant analysis, classification trees) methods of statistical analysis were used. The amino acid composition of 28 samples of uroliths differing in chemical types (urate, oxalate and phosphate) was studied. Onedimensional statistical methods revealed statistically significant differences in the contents of Gly, Glu, Asp, and Lys for various types of uroliths in their paired comparison. It was found that phosphates and oxalates are statistically significantly different from urates by relative contents of Gly and Glu, but do not differ from each other. Only urates and phosphates have statistically significant differences in Asp content. By the content of Lys, only phosphates and oxalates differ statistically significantly, but other pairs of urinary stones do not differ. It should be noted that none of the amino acids distinguish between pairs of all three types of urinary stones. The applied multidimen sional classification methods (discriminant analysis and classification trees) made it possible to graphically demonstrate the differences between different types of uroliths by amino acid composition. Statistical analysis of the amino acid composition of uroliths (oxalate, phosphate and urate) revealed distinctions in their protein component and its relationship with the basic mineral components (whewellite and weddellite, struvite and apatite, uric acid). The obtained results confirm the important role of proteins in the processes of formation and growth of urinary stones.