Metabolic risk factors and urinary stones formation. VI: Сalciuria lithogenic features in men and women.

Introduction. Hypercalciuria is one of the main factors in the formation of the most common calcium-containing stones. Urolithiasis (UL) is more common in men than in women, which indicates the existence of gender lithogenic factors. In this work, the effect of varying degrees of calciuria in stone formers (men and women) on metabolic parameters and the frequency of detection of urinary stones of various chemical composition was investigated. Materials and methods. A total of 982 patients with UL (439 men and 543 women aged 18 to 79 years) were examined. To estimate lithogenic activity of calciuria in patients, the values of calcium excretion (mmol/day) were ranked in ascending order and divided into 10 equal parts (ten 10%-х percentilesей). In each of the calciuria ranges кальциурии, the percentage distribution of urinary stones types and biochemical blood and urine parameters were determined. Results. As the degree of calciuria increased from minimum to maximum values, the proportion of oxalate stones in men increased by 1.4-2 times, compared with women (χ2 test for trend p<0.02), and in women there was an increase in the proportion of carbonatapatite stones compared with men by 2-2.9 times (p<0.025, χ2 test). Increasing calciuria was accompanied by an increase in excretion, uric acid, phosphates and magnesium, which was more pronounced in men than in women (p<0.0001) and positively correlated in patients of both sexes with an increase in the frequency of detection of oxalate stones (p<0.05). The frequency of detection of carbonatapatite stones in men was directly dependent on calcium excretion (r=0.6783, p=0.0314). There was no such dependence in women, despite their high proportion of these stones, unlike men. Oxalate stones are more common in men in all age groups (20-70 years). In women, the greatest predominance of carbonatapatite stones is observed in the period from 20 to 40 years. Conclusion. Gender features of lithogenesis are clearly revealed at calciuria, which increases from minimum to maximum values. At the same time, the frequency of oxalate stones formation increases in men. Women have a high percentage of carbonatapatite stones, which, however, did not depend on the severity of calciuria. Thus, there are certain sex differences in lithogenesis of calcium stones and in dynamics of metabolic parameters of excretion, depending on the severity of calciuria, which can be used to assess the risk of stone formation and to implement a personalized approach to metaphylaxis of urolithiasis.