Insulin Resistance in ICU Patients: Women Have Stronger Metabolic Response

Abstract

Glycaemic control (GC) has been associated with improved outcomes in critically ill patients. However, inter- and intra- patient metabolic variability significantly increase the risk of hypoglycaemia when using insulin to control glycaemia. Model-based protocols often identify key physiological parameters from patient data, and demonstrated safe and effective GC. Based on recent studies showing gender difference in insulin secretion, this study uses retrospective data to identify whether there exists a difference in sexes in metabolic stress response, and thus in how personalised GC is given. Retrospective data from 145 ICU patients under GC who started GC in the first 12 hours of ICU stay are used. Insulin sensitivity (SI) is identified hourly, as well as the hour-to-hour percentage change in SI (%ΔSI). Differences between males and females SI and %ΔSI over 6-h blocks are compared using hypothesis and equivalence testing. A difference in SI levels would suggest a difference in metabolic stress response to insult, while a difference in %ΔSI levels would suggest a resulting difference in the difficulty to control. Results show females are significantly more insulin resistant than males and not equivalent, suggesting stronger stress response to insult induced stress. Metabolic variability is equivalent in both groups, advocating GC safety and efficacy should be similar between males and females, despite potential higher insulin rates required for females. This study is the first to suggest potential gender differences in the metabolic stress response.