title: Impact of urinary cadmium on mortality in the Japanese general population in cadmium non-polluted areas.
abstract: OBJECTIVE
  The aim of the present study was to evaluate the dose-effect relationship between urinary cadmium (U-Cd as an index of internal Cd exposure) and mortality in a cohort of the Japanese general population.
  
  
  METHODS
  A 19-year cohort study was conducted in 897 men and 1307 women who lived in two non-polluted areas in Japan. The subjects were categorized into four quartiles based on creatinine adjusted U-Cd (μg/g cre). Hazard ratio (HR) and 95% confidence interval (95%CI) of the quartiles of U-Cd for mortality was calculated using a proportional hazards regression. Forward stepwise model selection was applied to the potential covariates such as age, body mass index, mean arterial pressure, various lifestyle factors and present illness.
  
  
  RESULTS
  The mortality rates per 1000 person years were 27.8 and 12.5 in men and women, respectively. In men, the fourth quartile of U-Cd (≥ 2.919 μg/g cre) showed a significant, positive HR (1.50, 95%CI: 1.11-2.02) for mortality compared to the first quartile (< 1.014). In women, the fourth quartile of U-Cd (≥ 3.943 μg/g cre) also showed a significant HR (1.50, 95%CI: 1.08-2.09) for mortality compared to the first quartile (< 1.140).
  
  
  CONCLUSIONS
  The present study clarified that U-Cd was significantly associated with increased mortality, indicating the worsened life prognosis of the general population in Cd non-polluted areas in Japan. These results highlight the importance of further discussion of the health risk assessment of Cd exposure in the general population.
authors.affiliation: Department of Occupational and Environmental Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuoku, Chiba 260-8670, Japan. Electronic address: suwa@faculty.chiba-u.jp.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Suwazono
authors.affiliation: Department of Occupational and Environmental Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuoku, Chiba 260-8670, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nogawa
authors.affiliation: Department of Epidemiology and Public Health, Kanazawa Medical University, 1-1 Daigaku, Uchnada, Ishikawa 920-0293, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Morikawa
authors.affiliation: Department of Epidemiology and Public Health, Kanazawa Medical University, 1-1 Daigaku, Uchnada, Ishikawa 920-0293, Japan.
authors.forename: Muneko
authors.initials: M
authors.lastname: Nishijo
authors.affiliation: Department of Occupational and Environmental Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuoku, Chiba 260-8670, Japan.
authors.forename: Etsuko
authors.initials: E
authors.lastname: Kobayashi
authors.affiliation: Department of Community Health Nursing, Kanazawa University School of Health Sciences, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Kido
authors.affiliation: Department of Epidemiology and Public Health, Kanazawa Medical University, 1-1 Daigaku, Uchnada, Ishikawa 920-0293, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nakagawa
authors.affiliation: Department of Occupational and Environmental Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuoku, Chiba 260-8670, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Nogawa
mesh_terms: D000368:Aged; D002104:Cadmium / Q000009:adverse effects* / Q000652:urine; D015331:Cohort Studies; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D004785:Environmental Pollutants / Q000009:adverse effects* / Q000652:urine; D004787:Environmental Pollution; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009026:Mortality; D018570:Risk Assessment
chemical_list: D004785:Environmental Pollutants; D002104:Cadmium
keywords: Cohort study; Cox's proportional hazard model; Life prognosis; Urinary cadmium