Epidemiology of urolithiasis: an update.

Background & Aim. Changing socio-economic conditions generated changes in the prevalence, incidence and distribution for age, sex and type of urolithiasis in terms of both the site and the chemical-physical composition of the calculi.In the latter part of the 20(th) century the prevalence of upper urinary tract stones was increasing in Western countries whereas endemic infantile bladder stone disease was fairly widespread in huge areas of developing countries. The aim of this paper was to update previous epidemiological reports of urolithiasis by reviewing the more recent literature.Methods. Citations were extracted using PubMed database from January 2003 through December 2007 on the basis of the key words epidemiology AND urinary calculi. Results. An increase in the prevalence and incidence of urolithiasis was described in Germany whereas data from the United States were contradictory with stone disease rates increased only for women with a change of male-to-female ratio. Prevalence figures of stone disease observed in some developing country in tropical regions were similar to rates of Western countries with incidence of renal colic particularly high in warm months. African Americans had a reduced risk of stone disease compared to other racial groups but in renal stone patients all racial groups demonstrated a similarity in the incidence of underlying metabolic abnormalities. Upper urinary tract stones in children were associated more frequently with metabolic disturbances rather than with urinary tract anomalies and infection. Endemic childhood bladder stones are still present in some developing countries.Dietary risk factors for stone disease were shown different by age and sex. In particular in younger women dietary calcium, phytate and fluid intake were associated with a reduced risk of stone formation whereas animal protein and sucrose increased the risk of stone incidence. In older adults there was no association between dietary calcium and stone formation whereas magnesium, potassium and fluid intakes decreased and total vitamin C intake increased the risk of symptomatic nephrolithiasis. Animal protein was associated with risk only in men with a body mass index < 25 kg/m(2). Type 2 diabetes and several other coronary heart disease risk factors, including hypertension and obesity are associated with nephrolithiasis.