Urinary Co, Mn and Sr concentrations, cardiovascular disease and all-cause mortality in older Australian Women

Abstract

Introduction Exposure to metals, specifically cadmium and lead, has been associated with increased risk of cardiovascular disease (CVD) and overall mortality, however, there has been limited investigation of other metals and few studies have focused specifically on women. Methods This study investigated the association between metals exposure, CVD outcomes and all-cause mortality in elderly Australian women. Urinary metal concentrations were measured at baseline in 1359 women, mean age 75.2 ± 2.7 years and 14.5 years of atherosclerotic vascular disease (ASVD) events and deaths were retrieved from the Western Australian Data Linkage System. Urinary metals concentrations were measured using ICPMS and ln-transformed and Cox regression models were adjusted for demographic and CVD risk factors including age, BMI, hypertension, prevalent ASVD, kidney function, low dose aspirin use, smoking history (yes/no) and pack years smoked. Results Concentrations of urinary metals were low: median (IQR) Co 0.07 (0.04-0.13); Mn 0.39 (0.23-0.70); Sr 20.0 (11.7-33.7) µg/L. In multivariable-adjusted analyses, a ln unit (equivalent to 2.7 fold) increase in urinary Co or Mn concentrations was associated with a 32% increase in the Hazard ratio (HR) for death from heart failure (Co HR=1.325, 95% CI 1.09-1.61; Mn HR=1.32, 95% CI 1.07-1.63), a ln-unit increase in Sr was associated with a 70% increase in HR for heart failure death (HR=1.70, 95% CI 1.31-2.22). Increased urinary metals concentrations were also associated with increased HR for ASVD deaths (Co HR=1.19, 95% CI 1.07-1.32; Mn HR=1.13, 95% CI 1.01-1.27; Sr HR=1.26, 95% CI 1.09-1.45) and all-cause mortality (Co HR=1.14, 95% CI 1.06-1.24; Mn HR=1.10, 95% CI 1.01-1.20; Sr HR=1.14, 95% CI 1.03-1.26). Conclusions Despite the low urinary metals concentrations, increased Co, Mn and Sr were associated with increased CVD and all-cause mortality in older women. The relationship between urinary metals concentrations and CVD warrants further research.