Impact of Blood Glucose Levels on in ICU Morbidity and Mortality in Patients With Acute Decompensated Heart Failure

Stress hyperglycemia is a physiological response of blood glucose levels to stressful events or severe diseases through enhanced inflammatory or neuro-hormonal activation , typically reflecting the severity of the corresponding disease.

Diabetes mellitus may lead to hyperglycemia. However, it can happen as a result of stress hormones in crucial situations as well as in illness states, and is referred to as "Stress Hyperglycemia". Other names for this syndrome include "New onset Hyperglycemia", "In hospital Hyperglycemia", "Admission Hyperglycemia", "New Hyperglycemia", and "reactive Hyperglycemia". The prevalence of admission hyperglycaemia ranges from 25 to 50% depending on the hyperglycaemia definition cut-off adopted. The American Heart Association and the Endocrine Society Clinical Guidelines defined stress hyperglycaemia as a random plasma glucose level above 140 mg/dL at any given time for both diabetic and nondiabetic hospitalized patients.Studies have shown that an elevated admission blood glucose level, in correlation with a specific condition, such as: myocardial infarction, stroke, heart failure or pneumonia is associated with a higher in-hospital mortality, increased length of hospital stay, and a higher rate of in-hospital complications.

Heart failure (HF) is a complex clinical syndrome that results from structural or functional impairment of ventricular filling or ejection. Also, HF is a progressive condition with intermittent acute decompensation leading to poor prognosis despite established guideline-directed therapy.Acute decompensated heart failure is a common reason for frequent hospital admission and has been associated with increased short-term mortality and poor long-term prognosis. Admission hyperglycaemia can be useful in identifying high-risk group of acute heart failure or in the risk stratification of acute heart failure In addition to age, obesity and diabetes have been identified as important risk factors for heart failure, Heart failure often manifests as the first cardiovascular event in people with type 2 diabetes.Several potential mechanisms contributing to the development of heart failure in diabetes include renin-angiotensin-aldosterone system (RAAS) activation, mitochondrial dysfunction, oxidative stress, inflammation, changes in intracellular calcium homeostasis, increased formation of advanced glycation end products, and myocardial energy substrate alterations including increased free fatty acid utilization, decreased glucose utilization, and increased oxygen consumption, resulting in decreased cardiac efficiency .

Dysregulation of hyperglycemia and glycemic variability are associated with an increased risk of mortality in critically ill patients .

It is also to be noted that individuals with HF and pre-diabetes have a higher risk of all-cause mortality and cardiac outcomes compared to those with normoglycemia.