title: Toenail zinc level and gastric cancer risk in Cali, Colombia.
abstract: OBJECTIVE
  To examine the associations between gastric cancer (GC) risk and the zinc levels in toenail clippings, we conducted a hospital-based case-control study during the period from 2000 to 2002 in Cali, Colombia.
  
  
  METHODS
  Toenail clippings and information on lifestyles including dietary habits were obtained from 156 GC patients newly diagnosed in three hospitals in Cali and 287 controls selected from non-cancer patients who were hospitalized in the same hospitals as GC patients. Zinc concentrations in toenail clippings were examined using inductively coupled plasma mass spectrometry.
  
  
  RESULTS
  An inverse association was observed between toenail zinc level and GC risk (P for trend = 0.039). When we examined this association separately for current and former smokers and non-smokers, only current-smokers showed a significant inverse association (P for trend = 0.035). Histology specific analysis revealed that this inverse association was stronger when we limited GC cases with intestinal-type and their matched controls (P for trend < 0.001). This association was also observed in the carcinomas located in the upper two-thirds of the stomach (P for trend = 0.004) but not in carcinomas in the lower-third of the stomach (P for trend = 0.727).
  
  
  CONCLUSIONS
  There was an inverse association between toenail zinc level and GC risk. However, the association was limited to smokers, intestinal-type GC, and tumors in the upper two-thirds of the stomach. Further studies seem warranted to confirm our findings.
authors.affiliation: Department of Epidemiology and Preventive Medicine, Kagoshima University, Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan.
authors.forename: Francia Ivonne
authors.initials: FI
authors.lastname: Campos
authors.forename: Chihaya
authors.initials: C
authors.lastname: Koriyama
authors.forename: Suminori
authors.initials: S
authors.lastname: Akiba
authors.forename: Gabriel
authors.initials: G
authors.lastname: Carrasquilla
authors.forename: Mauricio
authors.initials: M
authors.lastname: Serra
authors.forename: Edwin
authors.initials: E
authors.lastname: Carrascal
authors.forename: Megumi
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Nakano
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000473:pathology; D000368:Aged; D016022:Case-Control Studies; D003105:Colombia / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009262:Nails / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism*; D012307:Risk Factors; D012907:Smoking; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013054:Spectrophotometry, Atomic; D013274:Stomach Neoplasms / Q000453:epidemiology* / Q000473:pathology; D011795:Surveys and Questionnaires; D017967:Zinc Compounds / Q000378:metabolism*
chemical_list: D009566:Nitrates; D017967:Zinc Compounds; C042103:zinc nitrate