Diabetes patients and non-diabetic patients intensive care unit and hospital mortality risks associated with sepsis

AIM:To compare mortality risks associated with known diabetic patients to hyperglycemic non-diabetic patients.METHODS:PubMed data base was searched for patients with sepsis,bacteremia,mortality and diabetes.Articles that also identified new onset hyperglycemia (NOH) (fasting blood glucose>125 mg/dL or random blood glucose>199 mg/dL) were identified and reviewed.Nine studies were evaluated with regards to hyperglycemia and hospital mortality and five of the nine were summarized with regards to intensive care unit (ICU) mortality.RESULTS:Historically hyperglycemia has been believed to be equally harmful in known diabetic patients and non-diabetics patients admitted to the hospital.Unexpectedly,having a history of diabetes when admitted to the hospital was associated with a reduced risk of hospital mortality.Approximately 17% of patients admitted to hospital have NOH and 24% have diabetes mellitus.Hospital mortality was significantly increased in all nine studies of patients with NOH as compared to known diabetic patients (26.7%±3.4% vs 12.5% ±3.4%,P<0.05;analysis of variance).Unadjusted ICU mortality was evaluated in five studies and was more than doubled for those patients with NOH as compared to known diabetic patients (25.3%±3.3% vs 12.8%±2.6%,P<0.05) despite having similar blood glucose concentrations.Most importantly,having NOH was associated with an increased ICU and a 2.7-fold increase in hospital mortality when compared to hyperglycemic diabetic patients.The mortality benefit of being diabetic is unclear but may have to do with adaptation to hyperglycemia over time.Having a history of diabetes mellitus and prior episodes of hyperglycemia may provide time for the immune system to adapt to hyperglycemia and result in a reduced mortality risk.Understanding why diabetic patients have a lower than expected hospital mortality rate even with bacteremia or acute respiratory distress syndrome needs further study.CONCLUSION:Having hyperglycemia without a history of previous diabetes mellitus is a major independent risk factor for ICU and hospital mortality.