Effects of Blood Cadmium Levels on Blood Pressure and the Risk of Hypertension in a Community-Based Elderly Population

Cadmium (Cd) has been reported to contribute to hypertension, possibly by inducing renal function impairment, nevertheless, relevant epidemiologic evidence is limited. We aimed to investigate the effects of blood Cd on blood pressure and the risk of hypertension in a community-based elderly population. A total of 3,248 baseline participants from the Yiwu Elderly Cohort in China were enrolled in the study. Whole blood Cd concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS). Hypertension cases were identified by blood pressure measurements, self-reported history of hypertension, and use of antihypertensive medications. The median (interquartile range, IQR) blood Cd concentration was 1.33 (0.84, 2.16) μg/L. It showed a positively linear association between blood Cd concentrations and systolic blood pressure (SBP) levels (β = 2.69, 95% CI: 0.39–4.99). The results of age stratification showed blood Cd was positively associated with diastolic blood pressure (DBP) levels in the ≥ 75 years old group (β = 2.85, 95% CI: 0.45–5.26). The associations between blood Cd and the risk of hypertension were evaluated using multivariable log-binomial regression models. Comparing to the lowest quartile of Cd concentration, the risk of hypertension was 1.06 (95% CI: 1.01–1.11) times at the 3rd quartile (Q3) level. The risk of hypertension was 6% (PR = 1.06, 95% CI: 1.00–1.13) higher in women, and 10% (PR = 1.10, 95% CI: 1.01–1.21) higher in the 65–69 age group at the Q3 level, respectively. This cross-sectional study provides evidence for the positive association between blood Cd exposure and hypertension. In the future, more prospective studies are needed to validate our findings.