Hyperglycemia and insulin resistance in COVID-19 versus non-COVID critical illness: Are they really different?

 

by Lies Langouche, Greet Van den Berghe and Jan Gunst 

 

Critical Care volume 25, Article number: 437 (2021) Published: 17 December 2021

 

Hyperglycemia frequently develops in patients with severe COVID-19, regardless of preadmission diabetes status, as in non-COVID critically ill patients. In non-COVID patients, stress hyperglycemia has been attributed to insulin resistance due to elevated counterregulatory hormones, cytokines, and drugs including steroids, although beta-cell dysfunction through prolonged hyperglycemia, poor beta-cell reserve, hypoperfusion and inflammation may co-exist in some patients. As in non-COVID patients, numerous observational studies have associated more severe hyperglycemia and increased glucose variability with poor outcome in COVID-19 patients. However, causality remains unclear, since insulin resistance and resultant hyperglycemia closely relate to illness severity. In this regard, a recent observational study also associated insulin treatment with increased mortality of COVID-19. Evidently, observational studies have an inherent risk of residual confounding, whereby the ideal glucose target can only be derived from adequately powered randomized controlled trials (RCTs)…