Studies on the prevalence and epidemiology of urinary stone disease in men in Leeds.

A postal survey among 2% of men in Leeds showed that the prevalence of urinary stone disease is 3.8%. The prevalence of upper urinary tract and spontaneously passed stones increases progressively from 0.7% in social class 5 to 5.0% in social class 1 but that of bladder stones (0.7% in the group as a whole) is independent of social class. There is an initial peak of upper urinary tract and spontaneously passed stones commencing at age 20 and having a projected prevalence at age 90 of 5.7% and a second peak of bladder stones, commencing about age 50, with a projected prevalence of 1.9%. The prevalence of stone disease increases according to the order: single less than divorced/separated less than married less than widowed men. A family history of stones tends to be higher amongst relatives of stone-formers than amongst the corresponding relatives of control subjects, the male/female ratio being 2:1. The occurrence of urinary stones is significantly associated with that of gallstones, high blood pressure, backache, arthritis and gout but not with that of peptic ulcer, diabetes, thyroid disease or bronchitis.

Polyanionic inhibitors of calcium oxalate crystal agglomeration in urine.

The excretions and relative potencies of various macromolecular inhibitors of the crystallisation of calcium oxalate (CaOx) were measured in the urines of idiopathic calcium stone-formers and normal subjects. The stone-formers excreted significantly less polyanionic macromolecules in their urine than did the normals, the difference being attributable to the lower excretions of glycosaminoglycans (GAGS), ribonucleic acid (RNA) and Tamm-Horsfall mucoprotein (THM), all of which are precipitable with alcian blue. The relative potencies of the various inhibitors measured under 'whole urine equivalent' conditions using a batch crystallisation system, showed that the order of inhibitory activity towards CaOx crystal agglomeration was RNA greater than GAGS greater than THM greater than pyrophosphate (PPi). This paralleled the order of ability of these inhibitors to produce a high negative zeta potential on the surface of CaOx crystals.