Ultradian variation of blood glucose in intensive care unit patients receiving insulin infusions.

T reatment of hyperglycemia with an insulin infusion protocol (IIP) has improved outcomes in intensive care unit (ICU) patients (1,2). While morning glucose has been reported, little is known about variation of blood glucose for patients on IIP, causing uncertainty about the optimal treatment of ICU patients (3–5). Our objectives were to test whether morning glucose represented whole-day glucose and to determine whether glucose varied over the course of the day. In ICU patients receiving IIP, glucose was lower in the early morning, correlated poorly with average glucose, and varied with an ultradian pattern.