[The social infrastructure of patients with urinary calculi (author's transl)].

The social infrastructure was investigated in 379 patients with urinary stones. The rates of 50% for employees and 32% for old-age pensioners were surprisingly high. 16% of the patients were employed in jobs with hard manual labour. Only 9% of the patients went in for regular physical activity in their leisure. A significant increase in urinary excretion of calcium and uric acid (p - 0.01) and inorganic phosphate (p less than 0.001) was seen in connexion with increase in net income. On the other hand, urinary pH was lowest in the highest income group (p = 0.01). According to these findings an increased net income combined with a lack of physical exercise seems to enhance the risk of stone formation.