Blood and Urine Cadmium, Blood Pressure, and Hypertension: A Systematic Review and Meta-analysis

Abstract

BackgroundCadmium exposure has been inconsistently related to blood pressure.ObjectivesWe updated and reevaluated the evidence regarding the relationships of blood cadmium (BCd) and urine cadmium (UCd) with blood pressure (BP) and hypertension (HTN) in nonoccupationally exposed populations.Data sources and extractionWe searched PubMed and Web of Science for articles on BCd or UCd and BP or HTN in nonoccupationally exposed populations and extracted information from studies that provided sufficient data on population, smoking status, exposure, outcomes, and design.Data synthesisTwelve articles met inclusion criteria: eight provided data adequate for comparison, and five reported enough data for meta-analysis. Individual studies reported significant positive associations between BCd and systolic BP (SBP) among nonsmoking women [β = 3.14 mmHg per 1 μg/L untransformed BCd; 95% confidence interval (CI), 0.14–6.14] and among premenopausal women (β = 4.83 mmHg per 1 nmol/L log-transformed BCd; 95% CI, 0.17–9.49), and between BCd and diastolic BP (DBP) among women (β = 1.78 mmHg comparing BCd in the 90th and 10th percentiles; 95% CI, 0.64–2.92) and among premenopausal women (β = 3.84 mmHg per 1 nmol/L log-transformed BCd; 95% CI, 0.86–6.82). Three meta-analyses, each of three studies, showed positive associations between BCd and SBP (p = 0.006) and DBP (p < 0.001) among women, with minimal heterogeneity (I2 = 3%), and a significant inverse association between UCd and HTN among men and women, with substantial heterogeneity (I2 = 80%).ConclusionOur results suggest a positive association between BCd and BP among women; the results, however, are inconclusive because of the limited number of representative population-based studies of never-smokers. Associations between UCd and HTN suggest inverse relationships, but inconsistent outcome definitions limit interpretation. We believe a longitudinal study is merited.

Endothelial dysfunction in subjects with chronic cadmium exposure

“…Kidneys are the critical target organs of cadmium toxicity. Urinary Cd excretion is a good marker of long-term Cd exposure and body burden while blood Cd may represent recent exposure (Jarup et al, 1998;Gallagher and Meliker, 2010). Collectively, our findings suggest the endothelial dysfunction in Cdexposed subjects.…”

Hepatocellular carcinoma and the risk of occupational exposure

“…Some studies have reported that chronic exposure to Cd increases the risk of tumors in humans [288][289][290] . However, large epidemiological studies are necessary to demonstrate whether long term Cd contamination is responsible for HCC development in humans, as in animal models.…”

The effect of heavy metal air pollution arising from local metallurgical activities on albino rat

“…The higher BCF of Pb, Cu, Ni and Cd in liver compare to other organs could be attributed to the fact that the route of heavy metal entry into the experimental organism is not only via the lungs as the mouth and the skin can also serve as route of entry [1]. The high BCF recorded in this studies could be the reason why vacuolization, necrosis and nucleus condensation were noticed in the liver [51,52,53]. Higher BCF was also obtained in the lungs, kidney and heart, this higher BCF are responsible for the degenerated renal tubules, Bowman's capsule and contraction of glomeruli with reference to the kidney [49], lung and heart irritation [50,51].…”