Hyperglycemia and Hypoglycemia Contributions to Acute Respiratory Distress Syndrome

ABSTRACT

Purpose of Study Non-diabetic COVID-19 patients with elevated admission fasting blood glucose levels ('hyperglycemia') inexplicably have an increased 28 day mortality and higher inhospital complications including the Acute Respiratory Distress Syndrome (ARDS) but potentially contributing blood glucose changes during ARDS development were not reported (Wang S et al Diabetologia 2020). Our goal was to determine blood glucose alterations before and during acute lung injury development in a rat model used to study ARDS. Methods Used We sequentially evaluated blood glucose levels for 24 hours and lung lavage protein levels (lung permeability) and lung lavage neutrophil numbers (lung inflammation) at 24 hours to assess acute lung injury ('ARDS') in young (~3 month) and old (~12 month) control and a novel strain of hyperoxia surviving 'resistant' rats before and after administering high and low insulin doses and before and after interleukin- 1/lipopolysaccharide (IL-1/LPS) insufflation. Summary of Results Glucose levels increase rapidly and sequentially in young control, but not young resistant, rats peaking ~2 hours after insufflation. Glucose levels also increase in old control and old resistant rats after insufflation compared to young control and young resistant rats after insufflation. The pattern of glucose levels at 2 hours after insufflation resembles lung lavage proteins and neutrophils at 24 h after insufflation (table 1). Administering high insulin (High In) doses decreases glucose levels ('hypoglycemia') and worsens ARDS while administering low insulin (Low In) doses correct glucose levels and improve ARDS. Conclusions Hyperglycemia develops in both young and old rats developing ARDS and high or low glucose levels parallel worse acute lung inflammation and acute lung injury ('ARDS'). Controlling glucose judiciously with insulin may be beneficial in combatting ARDS caused by SARS-CoV-2 infection and other insults.