Low Level of Serum Cadmium in Relation to Blood Pressures Among Japanese General Population

Hypertension (HT) is an important risk factor for mortality and morbidity. Previous studies showed that cadmium (Cd) was associated with increased blood pressures and the prevalence of HT. This study hypothesized that Cd, regardless of its level, may increase blood pressures/HT. The objective of this study was to examine the associations between a low level of serum Cd concentration and blood pressures/HT among a general population in the Iwaki area, Japan. This was a cross-sectional study, conducted in the Aomori prefecture with 1144 volunteers aged over 19 years old, who were participants of the Iwaki health check-up in 2014. The study assessed questionnaire survey, body composition, and serum Cd concentrations. Median serum Cd concentration was 0.06 ng/mL (interquartile range 0.05–0.08 ng/mL) among our study population. Compared to the lowest quintile of serum Cd concentration group, the highest quintile of serum Cd concentration group had 4.9 mmHg higher systolic blood pressure (SBP) (95% confidence interval [CI] 1.53–8.31, p < 0.01) and 2.4 mmHg higher diastolic blood pressure (DBP) (95% CI 0.36–4.34, p < 0.05), compared to the lowest quintile group. Similarly, the highest quintile of serum Cd concentration group had 1.7 times higher prevalence of HT (95% CI 1.10–2.51, p < 0.05) than the lowest quintile group. This study identified that higher serum Cd concentration was significantly, positively, associated with SBP and DBP and HT prevalence. This study provided evidence for the associations between environmental exposure to Cd and blood pressures/HT which should be considered for future preventive measures.