Urinary metal levels associated with risk for cardiovascular disease

Urinary levels of certain metals were associated with higher coronary artery calcium (CAC) scores at baseline and 10 years, a recent study found.

Researchers used data from the Multi-Ethnic Study of Atherosclerosis (MESA) to evaluate whether exposure to metals could be related to progression of atherosclerosis. Linear mixed-effect models were used to assess the association of urinary metal levels at baseline with baseline CAC and cumulative change in CAC over a 10-year period, with adjustment for sociodemographic characteristics, estimated glomerular filtration rate, and clinical and lifestyle factors. The results were published by JACC on Sept. 18.

The analysis included data from 6,418 MESA participants who had spot urinary metal levels available at baseline and one to four repeated, continuous measures of CAC over 10 years. The median CAC at baseline was 6.3, ranging from 0.7 in quartile 1 to 58.2 in quartile 3. Those in the highest quartile of urinary cadmium had CAC scores that were 51% (95% CI, 32% to 74%) higher at baseline and 75% (95% CI, 47% to 107%) higher over the 10-year period compared with those in the lowest quartile of urinary cadmium. CAC scores over the 10-year period were 45% (95% CI, 23% to 71%), 39% (95% CI, 17% to 64%), and 47% (95% CI, 25% to 74%) higher in the highest versus lowest quartiles of urinary tungsten, uranium, and cobalt, respectively. Corresponding estimates for copper and zinc decreased from 55% to 33% and from 85% to 57% after adjustment for clinical risk factors. The association of urinary metal levels with CAC was similar to that of classic cardiovascular disease risk factors.

“This large, longitudinal study among diverse U.S. adults presents new evidence of the association between urinary biomarkers of cadmium and less studied tungsten, uranium, cobalt, copper, and zinc and CAC progression using repeated measures of CAC, which assesses the association with calcification over time,” the authors wrote. They called for large-scale public health actions to lower accepted limits of metals in air and water and better enforce metal pollution reduction regulations, particularly in the most affected communities.

An accompanying editorial said that the results of the study have important implications for public health, health equity, and clinical practice, suggesting that clinicians should consider environmental metal exposure an important risk factor for atherosclerotic cardiovascular disease.

“Future studies should investigate the role of incorporating metal exposure assessment in cardiovascular risk prediction, especially for patients in areas with known contamination or occupational exposures,” the editorialists wrote. “Overall, the study highlights the need for a more holistic approach to cardiovascular risk management that considers environmental factors alongside traditional risk factors.”