Hypoglycemia and hyperglycemia in critically ill cancer patients

Advances in cancer therapy and supportive care have led to increased survival of patients with cancer. Hyperglycemia and hypoglycemia, both associated with poor outcome, are glucose metabolism disorders seen frequently in patients with cancer that requires careful management. Hyperglycemia and hypoglycemia can be observed in all types of cancer, although some cancers may increase the risk of these complications. The incidence of hyperglycemia is higher than hypoglycemia. Estimated prevalence of hyperglycemia in nondiabetic critically ill patients is 30-40%, while 12-25% of hospitalized patients are diabetic. Cancer and diabetes are diagnosed in the same individual more frequently than would be expected by chance. Hypoglycemia during critical care has an incidence of 5-19% usually as a result of antidiabetic treatment. Tumorinduced hypoglycemia occurs more rarely and can involve several mechanisms. The American Diabetes Association (ADA) defines hyperglycemia in hospitalized patients as blood glucose levels greater than 140 mg/dl (7.8 mmol/L). Hyperglycemia in critically ill or cancer patients is mostly stress-induced, while hypoglycemia is mostly a consequence of insulin therapy. ADA recommends to initiate insulin treatment in persistent hyperglycemia in critically ill patients at a threshold of 180 mg/dl (10 mmol/L) and to set a target glucose level of 140-180 mg/dl, although tighter glucose targets may be appropriate for certain group of patients (e.g., postoperative care).