ObjectivesTo systematically review the relationship between cadmium exposure and the risk of hypertension.MethodsPubMed, EMbase, The Cochrane Library, CBM, WanFang Data, VIP and CNKI databases were searched online to collect studies of cadmium exposure and hypertension from inception to March 2018. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was then performed by Stata 12.0 software.ResultsA total of 9 studies were included, of which 19 841 cases were patients of hypertension, and 27 578 cases were in the control group. The results of meta-analysis showed that blood cadmium was associated with risk of hypertension (OR=1.23, 95%CI 1.17 to 1.30, P<0.001). However, no significant association was found between urinary cadmium and the risk of hypertension (OR=0.77, 95%CI 0.55 to 1.07,P=0.61). The results of subgroup analysis showed non-smokers (OR=1.19, 95%CI 1.09 to 1.31, P<0.001), males (OR=1.19, 95%CI 1.11 to 1.28,P<0.001), females (OR=1.28, 95%CI 1.18 to 1.40,P<0.001), yellow race (OR=1.26, 95%CI 1.19 to 1.34,P<0.001), and the literatures published after 2010 (OR=1.24, 95%CI 1.17 to 1.31,P<0.001) were associated with risk of hypertension in blood cadmium. The current smokers (OR=0.72, 95%CI 0.56 to 0.93,P=0.013), yellow race (OR=0.65, 95%CI 0.50 to 0.83, P=0.001), and the literatures published before 2010(OR=0.61, 95%CI 0.50 to 0.75, P<0.001) were associated with risk of hypertension in urinary cadmium.ConclusionsBlood cadmium is associated with risk of hypertension and high level of blood cadmium is a risk factor for hypertension. The levels of blood cadmium of non-smokers, males, females, yellow race are associated with risk of hypertension in blood cadmium. Urinary cadmium was not significantly associated with the risk of hypertension. The above conclusions are required to be verified by more high quality studies.
Objective To systematically review the dose-response relationship between cadmium exposure and the risk of stroke onset. Methods The PubMed, Web of Science, Cochrane Library, Embase, CNKI, VIP, WanFang Data, and CBM databases were electronically searched to collect studies related to objectives from inception to June 2024. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias of the included studies. Meta-analysis was then performed using Stata 15.1 software. Results There were 10 studies that involved 28 250 participants, and 7 of them were prospective cohort studies and 3 were case-control studies. Meta-analysis results showed that cadmium exposure significantly increased the risk of stroke (RR=1.39, 95%CI 1.20 to 1.59, P<0.01), blood cadmium exposure significantly increased the risk of stroke (RR=1.79, 95%CI 1.34 to 2.25, P<0.01), urinary cadmium exposure significantly increased the risk of stroke (RR=1.30, 95%CI 1.09 to 1.52, P<0.01). Blood cadmium exposure had a significantly nonlinear dose-response relationship associated with an increased risk of stroke (χ2=8.56, P<0.05). The risk of stroke increased by 15% with the blood cadmium exposure concentration of 0.8 μg/L (RR=1.15, 95%CI 0.98 to 1.36), and 51% with the blood cadmium exposure concentration of 1.2 μg/L (RR=1.51, 95%CI 1.14 to 2.01) than those without blood cadmium exposure. Urinary cadmium exposure had significantly linear dose-response relationship associated with an increased risk of stroke (χ2=2.47, P=0.12). The risk of stroke increased by 26% with the blood cadmium exposure concentration of 0.8 μg/L (RR=1.26, 95%CI 1.20 to 1.31), and 31% with the blood cadmium exposure concentration of 1.2 μg/L (RR=1.31, 95%CI 1.27 to 1.36) than those without urinary cadmium exposure. Conclusion Cadmium exposure increases the risk of stroke. There was a significant dose-response relationship between cadmium exposure and the risk of stroke.