title: Increase in the prevalence of symptomatic upper urinary tract stones during the last ten years.
abstract: OBJECTIVE
  In industrialized countries the prevalence of upper urinary tract stones has continually increased during the 20th century, but there are considerable differences between countries and also within the same country. To study whether there is still an increase in the frequency of renal stones, an investigation was undertaken to determine the prevalence of stone formers in a village near Milan, Italy, during two time periods, with an interval of 12 years.
  
  
  METHODS
  Questionnaires were administered in 1986 and 1998 to all adult (age >25 years) occupants of two random samples of households in the village. Participants were asked whether they had experienced a kidney stone during their lifetime.
  
  
  RESULTS
  The overall prevalence of stone formers among males was 6.8% in 1986 and 10.1% in 1998; that among females was 4.9% in 1986 and 5.8% in 1998. In all age classes, the respondents in the 1998 survey more frequently reported a history of stones than in 1986, but the prevalence of renal stones was significantly higher in 1998 than in 1986 only among males aged 31-40 and 51-60 years. The yearly incidence was estimated at 0.4%, with 0.6 and 0.18% in men and women, respectively.
  
  
  CONCLUSIONS
  This marked increase in renal stones could be the result of environmental factors such as dietary habits and lifestyle, in particular the influence of an increased consumption of animal protein should be considered.
authors.affiliation: Istituto di Urologia, IRCC Ospedale Maggiore di Milano, Italia. uropoli@imiucca.csi.it
authors.forename: A
authors.initials: A
authors.lastname: Trinchieri
authors.forename: F
authors.initials: F
authors.lastname: Coppi
authors.forename: E
authors.initials: E
authors.lastname: Montanari
authors.forename: A
authors.initials: A
authors.lastname: Del Nero
authors.forename: G
authors.initials: G
authors.lastname: Zanetti
authors.forename: E
authors.initials: E
authors.lastname: Pisani
mesh_terms: D000328:Adult; D017677:Age Distribution; D005260:Female; D006801:Humans; D007558:Italy; D007669:Kidney Calculi / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D013997:Time Factors