Cadmium and
nickel exposure can cause oxidative stress, induce
inflammation, inhibit immune function, and therefore has significant impacts on the pathogenesis and severity of many diseases. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
infection can also provoke oxidative stress and the dysregulation of inflammatory and immune responses. This study aimed to assess the potential associations of
cadmium and
nickel exposure with the severity and clinical outcomes of patients with
coronavirus disease 2019 (COVID-19).
METHODS: We performed a retrospective, observational, bicenter cohort analysis of patients with
SARS-CoV-2 infection in Taiwan between June 2022 and July 2023.
Cadmium and
nickel concentrations in blood and urine were measured within 3 days of the diagnosis of acute
SARS-CoV-2 infection, and the severity and clinical outcomes of patients with
COVID-19 were analyzed.
RESULTS: A total of 574 patients were analyzed and divided into a severe
COVID-19 group (hospitalized patients) (n = 252; 43.9%), and non-severe
COVID-19 group (n = 322; 56.1%). The overall in-hospital mortality rate was 11.8% (n = 68). The severe
COVID-19 patients were older, had significantly more comorbidities, and significantly higher neutrophil/lymphocyte ratio,
C-reactive protein, and
interleukin-6 than the non-severe
COVID-19 patients (all p < 0.05). Blood and urine
cadmium and urine
nickel concentrations were significantly higher in the severe
COVID-19 patients than in the non-severe
COVID-19 patients. Among the severe
COVID-19 patients, those in higher urine
cadmium/
creatinine quartiles had a significantly higher risk of organ failure (i.e., higher APACHE II and SOFA scores), higher neutrophil/lymphocyte ratio, lower PaO2/FiO2 requiring higher invasive
mechanical ventilation support, higher risk of
acute respiratory distress syndrome, and higher 60-, 90-day, and all-cause hospital mortality (all p < 0.05). Multivariable logistic regression models revealed that urine
cadmium/
creatinine was independently associated with severe
COVID-19 (adjusted OR 1.643 [95% CI 1.060-2.547], p = 0.026), and that a urine
cadmium/
creatinine value > 2.05 μg/g had the highest predictive value (adjusted OR 5.349, [95% CI 1.118-25.580], p = 0.036).
CONCLUSIONS: