title: Associations between cadmium levels in blood and urine, blood pressure and hypertension among Canadian adults.
abstract: Cadmium has been inconsistently related to blood pressure and hypertension. The present study seeks to clarify the relationship between cadmium levels found in blood and urine, blood pressure and hypertension in a large sample of adults.
  
  
  
  The study sample included participants ages 20 through 79 from multiple cycles of the Canadian Health Measures Survey (2007 through 2013) with measured blood cadmium (n=10,099) and urinary cadmium (n=6988). Linear regression models examined the association between natural logarithm transformed cadmium levels and blood pressure (separate models for systolic and diastolic blood pressure) after controlling for known covariates. Logistic regression models were used to examine the association between cadmium and hypertension. Models were run separately by sex, smoking status, and body mass index category.
  
  
  
  Men had higher mean systolic (114.8 vs. 110.8mmHg, p<0.01) and diastolic (74.0 vs. 69.6mmHg, p<0.01) blood pressure compared to women. Although, geometric mean blood (0.46 vs. 0.38µg/L, p<0.01) and creatinine-adjusted standardized urinary cadmium levels (0.48 vs. 0.38µg/L, p<0.01) were higher among those with hypertension, these differences were no longer significant after adjustment for age, sex and smoking status. In overall regression models, increases in blood cadmium were associated with increased systolic (0.70mmHg, 95% confidence interval [CI]=0.25-1.16, p<0.01) and diastolic blood pressure (0.74mmHg, 95% CI=0.30-1.19, p<0.01). The associations between urinary cadmium, blood pressure and hypertension were not significant in overall models. Model stratification revealed significant and negative associations between urinary cadmium and hypertension among current smokers (OR=0.61, 95% CI=0.44-0.85, p<0.01), particularly female current smokers (OR=0.52, 95% CI=0.32-0.85, p=0.01).
  
  
  
  This study provides evidence of a significant association between cadmium levels, blood pressure and hypertension. However, the significance and direction of this association differs by sex, smoking status, and body mass index category.
authors.affiliation: Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada. Electronic address: rochelle.garner@canada.ca.
authors.forename: Rochelle E
authors.initials: RE
authors.lastname: Garner
authors.affiliation: Direction de la santé environnementale et de la toxicologie, Institut National de Santé Publique du Québec, Québec City, Québec, Canada; Axe santé des populations et pratiques optimales en santé, Centre de Recherche du CHU de Québec-Université Laval, Québec City, Québec, Canada.
authors.forename: Patrick
authors.initials: P
authors.lastname: Levallois
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D002104:Cadmium / Q000097:blood* / Q000652:urine*; D002170:Canada / Q000453:epidemiology; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000097:blood* / Q000652:urine*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000453:epidemiology / Q000652:urine*; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000097:blood / Q000652:urine; D055815:Young Adult
chemical_list: D004785:Environmental Pollutants; D002104:Cadmium
keywords: Blood pressure; Body mass index; Cadmium; Canadian Health Measures Survey; Hypertension; Smoking