Glargine and Glycemia: Pitfalls and Perils

Abstract

Type 1 diabetics exhibit an unfulfilled basal insulin requirement, currently treated with long-acting subcutaneous insulins such as glargine. Due to glagine's unique flat peak the drug is an ideal basal insulin replacement. Use of the drug has extended beyond patients with diabetes, seeing use in critical care when patients are deemed stable but still require exogenous insulin. Data from four patients in the pilot trial of STAR in Christchurch hospital was gathered to outline serious considerations when using glargine in an ICU setting. The patients were fitted with the ICING and Glargine Compartment models to identify time-varying insulin sensitivity (SI), which was plotted alongside the blood glucose (BG) trace, interstitial insulin compartment and insulin/nutrition inputs. Features of these profiles were then identified to elaborate on the risks associated with the use of a long-acting insulin analogue. Importance of nutrition on patient safety, uncertainty in inter- and intra- patient variability in response to glargine doses, and time-scales of changes in patient condition were all highlighted from the four cases. The extended time-scale of physiological responses to glargine can put patients at risk of severe hypoglycemia if: A) metabolic condition changes dramatically within this period; or B) clinical limitations on nutrition are imposed after a dose is administered. Although use of glargine has the potential to cater for patients with a basal insulin requirement and who have less requirement for intensive supervision, more research should be done into action of the drug in an ICU cohort before use becomes widespread.