title: Artificial neural networks for assessing the risk factors for urinary calcium stones according to gender and family history of stone.
abstract: OBJECTIVE
  In a previous work, we evidenced that artificial neural networks (ANNs) were more informative than classical statistical analyses for assessing the risk of idiopathic calcium nephrolithiasis in male stone-formers.
  
  
  METHODS
  We compared risk factors for idiopathic calcium nephrolithiasis (age, body mass index, calcemia, calcium oxalate supersaturation, and 24-h calciuria, oxaluria, uricosuria, citraturia, urea, and sodium) in four populations: men and women with and without a family history of stone (FHS). A total of 119 males (58 with an FHS, 61 without) and 59 females (30 with an FHS, 29 without) were compared to healthy controls. For each variable, receiver operating characteristic (ROC) curve indices were calculated by means of ANNs.
  
  
  RESULTS
  In men without an FHS, the most discriminant variables were 24-h urea (ROC curve index 0.76), supersaturation (ROC curve index 0.72), 24-h calciuria (ROC curve index 0.68), 24-h uricosuria (ROC curve index 0.64), 24-h oxaluria (ROC curve index 0.63), 24-h sodium (ROC curve index 0.62), and calcemia (ROC curve index 0.60). In men with an FHS, only supersaturation (ROC curve index 0.67) was discriminant. In women without FHS, calcemia (ROC curve index 0.67), 24-h calciuria (ROC curve index 0.64), and 24-h uricosuria (ROC curve index 0.62) were discriminant. In women with an FHS, supersaturation (ROC curve index 0.70), 24-h uricosuria (ROC curve index 0.69), 24-h urea (ROC curve index 0.68), and 24-h calciuria (ROC curve index 0.67) were discriminant.
  
  
  CONCLUSIONS
  Risk factors for idiopathic calcium nephrolithiasis were roughly the same in men with or without an FHS, and in women with an FHS. In these patients, calcium oxalate supersaturation and 24-h urea were the most discriminant factors. Conversely, in women without an FHS, calcium abnormalities (calcemia, 24-h calciuria) were discriminant and should prompt a search for infraclinical primary hyperparathyroidism or sarcoidosis.
authors.affiliation: Centre de Néphrologie et de Transplantation Rénale, Hôpital de la Conception, Marseille, France. bdussol@ap-hm.fr
authors.forename: Bertrand
authors.initials: B
authors.lastname: Dussol
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Verdier
authors.forename: Jean-Marc Le
authors.initials: JM
authors.lastname: Goff
authors.forename: Patrice
authors.initials: P
authors.lastname: Berthezene
authors.forename: Yvon
authors.initials: Y
authors.lastname: Berland
mesh_terms: D000293:Adolescent; D000328:Adult; D002129:Calcium Oxalate / Q000378:metabolism*; D016022:Case-Control Studies; D005190:Family; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D016571:Neural Networks, Computer; D011237:Predictive Value of Tests; D012372:ROC Curve; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012727:Sex Characteristics
chemical_list: D002129:Calcium Oxalate