Stress-induced hyperglycemia is a valuable biomarker in febrile neutropenia

Stress-induced hyperglycemia (SIH) is a transient condition that occurs in patients with acute diseases such as trauma, stroke, surgery and sepsis. Claude Bernard, the eminent French physiologist, described for the first time in 1855 that critically-ill patients tended to show hyperglycemia (1). In the beginning, it was supposed to be an ancient and adaptive response of tissues requiring large amounts of energy. But by the late 60s, it became clear that SIH was exceedingly frequent in critically-ill patients, and that negative outcomes were generally associated (2). Since then, there has been a growing interest among clinicians on SIH, although its contribution to risk stratification and therapeutic management remains controversial. More recently, SIH has been described as a significant predictor of poor prognosis in cancer patients with febrile neutropenia (FN). In this issue, Matias et al. have shed some light on the meaning of SIH in patients with FN in the scenario of induction chemotherapy for acute leukemia (3). This is indeed a high-risk clinical setting in which the expected rate of infectious-related complications and death has been reported to be around 15% (4) ; hence, it is crucial to identify the groups at highest risk for developing life-threatening events in order to design preventive interventions. This is precisely the medical environment in which acute phase biomarkers are especially attractive, since the ineffectiveness of the inflammatory response sets hurdles for assessing the severity of most of the neutropenic infections (5). In contrast, sources of infection are immediately obvious in non-neutropenic patients and clinical variables are sufficiently informative in these cases. In agreement with previous reports, Matias et al. found that whereas the prevalence of diabetes is relatively low (5.8%) in this high-risk population, SIH is commonly observed (67.1%) during induction chemotherapy (3). Moreover, SIH, not diabetic hyperglycemia, was associated with unfavorable outcomes during the course of FN. In fact, after adjusting for comorbidities and other well-known variables, the independent risk factors for severe complications were bacteremia, hypoglycemia and SIH. These data are encouraging for further research to validate the role of SIH as a prognostic marker in large prospective studies. If confirmed, SIH would finally become a valuable, inexpensive and 'easy-to-get' tool in daily clinical practice that could contribute to improve the algorithms of supportive care in the setting of acute leukemia (6). Although sophisticated biomarkers, such as sTREM-1 and PTX3 are being tested as diagnostic tools in the field of …