title: [Prevalence of porphyria cutanea tarda in Madrid and relationship between urine porphyrin and ethanol intake in a multiple linear regression model].
abstract: BACKGROUND
  The application of a simple fluorometric analytical method enabled us to quantify the urinary porphyrin excretion and to establish the prevalence of porphyria cutanea tarda (PCT) in the town of Madrid, Spain, in a cross-sectional study.
  
  
  METHODS
  The study assessed 1,613 subjects from three districts in Madrid, in whom further variables potentially related to porphyrinuria such as ethanol intake or -in women-oral contraceptive use were measured and recorded.
  
  
  RESULTS
  The estimated prevalence of the disease was 1.24 cases per 1,000 inhabitants (95% confidence interval 0.15-4.47 per thousand). After excluding from the study sample all cases with existent disease, an analysis was performed to ascertain an unilateral tolerance interval for urinary porphyrin concentration in the adult population; this level was established at 181.2 micrograms/l. The effect of ethanol intake on porphyrinuria was considered significant using a multiple linear regression model adjusted for the control variables gender, age and body mass index. In fertile women, contraceptive use did not attain statistical significance when that variable was included in a multiple regression model.
  
  
  CONCLUSIONS
  A high prevalence has been estimated for PCT in the Madrid population. A significant association was further found between alcohol intake and porphyrinuria in non-porphyric adults.
authors.affiliation: Unidad de Porfirias, Hospital 12 de Octubre. Universidad Complutense, Madrid.
authors.forename: J L
authors.initials: JL
authors.lastname: Santos
authors.forename: M
authors.initials: M
authors.lastname: Grandal
authors.forename: A
authors.initials: A
authors.lastname: Fontanellas
authors.forename: M J
authors.initials: MJ
authors.lastname: Morán
authors.forename: R
authors.initials: R
authors.lastname: Enríquez de Salamanca
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000652:urine*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D017119:Porphyria Cutanea Tarda / Q000453:epidemiology* / Q000652:urine; D011166:Porphyrins / Q000652:urine*; D015995:Prevalence; D013030:Spain / Q000453:epidemiology
chemical_list: D011166:Porphyrins
vernacular_title: Prevalencia de porfiria cutánea tarda en Madrid y asociación entre la porfirinuria y el consumo de etanol en un modelo de regresión lineal múltiple.