Iron, selenium, copper and magnesium in critical care: Impact on acquired weakness risk through Mendelian randomization.

Background: Trace elements play a crucial role in the health of critically ill patients, yet their impact on acquired weakness remains unclear.

Aim: This study utilized Mendelian randomization (MR) to explore the relationship between iron, selenium, copper, magnesium, zinc and debilitation risk in this population. The aim of study was to investigate the influence of specific trace elements on acquired weakness in critically ill patients and determine their protective or risk effects.

Study design: This project collected a total of 164 627 exposure related datasets and 4 518 732 outcome related datasets. Mendelian randomization was employed to analyse data on trace elements in critically ill patients, assessing how iron, selenium, copper, magnesium and zinc may impact debilitation risk.

Results: This study explored the causal relationships between trace elements (iron, copper, zinc, selenium and magnesium) and outcomes (muscle dysfunction, muscle damage and respiratory infections) in critically ill patients. For example, the analysis of iron (ukb-b-20 447) and diaphragmatic hernia (ukb-b-8848) using the Inverse Variance Weighted (IVW) method showed an odds ratio (OR) of 0.996 (95% CI: 0.993-0.999, p = .004). Overall, MR results indicated that iron and selenium are protective factors, while copper and magnesium are risk factors for acquired weakness. Zinc was not causally associated with acquired weakness in critically ill patients.

Conclusions: This study highlights the importance of understanding the role of specific trace elements in acquired weakness among critically ill patients, providing valuable insights for personalized care strategies to enhance patient outcomes.

Relevance to clinical practice: The findings offer new theoretical foundations and potential molecular targets for the prevention and treatment of debilitation in critical care settings.