Metabolic risk factors and the formation of urinary stones. Study X: Lithogenic properties of phosphaturia in men and women.

Introduction. The role of hyperphosphaturia in calcium phosphate stones formation, including gender-specific features of its lithogenic properties in male and female patients, is still unclear. In this study, we investigated the effect of varying degrees of phosphaturia in stone formers men and women on metabolic parameters and the urinary stones frequency. Materials and methods. We examined 981 stone formers (438 men and 543 women aged 18 to 79 years). To assess the lithogenic activity of phosphaturia in stone formers men and women, the values of phosphate excretion (in mmol/day) were ranked in ascending order and divided into 10 equal parts (ten 10%-х percentilesей). In each of the ranges, the percentage distribution of types of urinary stones and biochemical parameters of urine and blood were determined. Results. As the degree of phosphaturia increased from minimum to maximum values the number of calcium oxalate stones among male patients increased 1,3-2,3 times (p=0,0001), and the frequency of detection of oxalate stones increased 1,61 times (p=0,0247), in contrast to women. In women, the proportion of carbonatapatite stones increased by 1,3-2,9 times (p<0,0001), and the c