<qa>  What is the name of the study Leuvens study?INTRODUCTION High blood glucose levels and insulin resistance are frequently registered in critically ill patients. In the past, hyperglycemia due to stress was considered as an adaptive body reaction to satisfy higher energetic requests. This theory has been re-discussed after Leuvens study in 2001, which demonstrated that a strict glycemic control, by means of intensive insulin administration, may reduce mortality in critically ill patients. However, more recent randomized controlled studies cannot confirm these results, showing how an intensive insulinic therapy can be associated to an higher risk of hypoglycemia and death. 