Calcium Intake and Serum Calcium Level in Relation to the Risk of Ischemic Stroke: Findings from the REGARDS Study / 대한뇌졸중학회지

BACKGROUND AND PURPOSE: Data on the association between calcium (Ca) and ischemic stroke are sparse and inconsistent. This study aimed to examine Ca intake and serum Ca levels in relation to risk of ischemic stroke. METHODS: The primary analysis included 19,553 participants from the Reasons for Geographic And Racial Differences in Stroke (REGARDS) study. A subcohort was randomly selected to create a case-cohort study (n=3,016), in which serum Ca levels were measured. Ischemic stroke cases were centrally adjudicated by physicians based on medical records. Cox proportional hazards regression for the cohort and weighted Cox proportional hazard regression with robust sandwich estimation method for the case-cohort analysis with adjustment for potential confounders were performed. RESULTS: During a mean 8.3-year follow-up, 808 incident cases of ischemic stroke were documented. Comparing the highest quintile to the lowest, a statistically significant inverse association was observed between total Ca intake and risk of ischemic stroke (hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.55 to 0.95; P(linear-trend)=0.183); a restricted cubic spline analysis indicated a threshold effect like non-linear association of total Ca intake with ischemic stroke (P(non-linear)=0.006). In the case-cohort, serum Ca was inversely associated with the risk of ischemic stroke. Compared to the lowest, the highest quintile of serum Ca had a 27% lower risk of ischemic stroke (HR, 0.73; 95% CI, 0.53 to 0.99; P(linear-trend)=0.013). Observed associations were mainly mediated by type 2 diabetes, hypertension, and cholesterol. CONCLUSIONS: These findings suggest that serum Ca has inverse and Ca intake has threshold effect like association with risk of ischemic stroke.

Association between Blood Mercury Level and Visceral Adiposity in Adults

BACKGROUND: Few studies have examined the association between mercury exposure and obesity. The aim of this study is to investigate the association between blood mercury concentrations and indices of obesity in adults. METHODS: A total of 200 healthy subjects, aged 30 to 64 years, who had no history of cardiovascular or malignant disease, were examined. Anthropometric and various biochemical profiles were measured. Visceral adipose tissue (VAT) was measured using dual-energy X-ray absorptiometry (DXA). RESULTS: All subjects were divided into three groups according to blood mercury concentrations. Compared with the subjects in the lowest tertile of mercury, those in the highest tertile were more likely to be male; were current alcohol drinkers and smokers; had a higher body mass index (BMI), waist circumference (WC), and VAT; had higher levels of blood pressure, fasting glucose, and insulin resistance; and consumed more fish. The blood mercury concentration was significantly associated with anthropometric parameters, showing relationships with BMI, WC, and VAT. After adjusting for multiple risk factors, the odds ratios (ORs) for high mercury concentration was significantly higher in the highest VAT tertile than in the lowest VAT tertile (OR, 2.66; 95% confidence interval, 1.05 to 6.62; P<0.05). CONCLUSION: The blood mercury concentration was significantly associated with VAT in healthy adults. Further studies are warranted to confirm our findings.