title: [A study of the differences between the sexes in epidemiology of urolithiasis].
abstract: OBJECTIVE
  Uroithiasis seems to be the dominant disease for male. In the recent Japanese epidemiological report, the sexual ratio was reported 2.3:1. This sexual ratio is almost stable from 1960. We studied epidemiologically based on age and stone components the differences between the sexes.
  
  
  METHODS
  From 1977 to 1996 the upper urinary tract stones which spontaneous excretion or surgical removal in our hospital were the subjects of study, Stone analysis was carried out infrared spectrometer. The statistical analyses were performed by the chi-square test and Mann-Whitney's U test. Significance was declared for a probability value of less than 0.05.
  
  
  RESULTS
  In the epidemiology of our treated patients sexual ratio was 1.83:1. We studied sexual ration in age and stone components. The sexual ratio of the patients, 60 years and over was decreased compared with that of the patients under 60 years of age. We found the tendency that the sexual ratio was decreased at 60 years old and over. In the female urolithiasis patients less than 60 years old the frequency of calcium oxalate contained stone patients was predominantly smaller than male. In the female urolithiasis patients of 60 years and over the stone component ratio was similar to male urolithiasis patients.
  
  
  CONCLUSIONS
  In point of frequency sexual ratio was decreased at 60 years old and over. In the female patients less than 60 years old the frequency of calcium oxalate contained stone was predominantly small. This low frequency of calcium oxalate contained stone in the female less than 60 years old seemed to be a factor of the sex differences of frequency.
authors.affiliation: Department of Urology, Asahikawa Medical College.
authors.forename: M
authors.initials: M
authors.lastname: Morikawa
authors.forename: M
authors.initials: M
authors.lastname: Okuyama
authors.forename: H
authors.initials: H
authors.lastname: Yoshihara
authors.forename: S
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: S
authors.initials: S
authors.lastname: Yachiku
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002129:Calcium Oxalate / Q000032:analysis; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D014545:Urinary Calculi / Q000737:chemistry / Q000453:epidemiology*
chemical_list: D002129:Calcium Oxalate