Effect of Glucose Variability on Morbidity and Mortality in Diabetic Patients Admitted in Coronary Care Unit

Diabetes mellitus (DM) is a major public health problem worldwide and represents one of the most important risk factors for cardiovascular disease. Patients with diabetes have a significantly higher incidence of coronary artery disease (CAD), acute coronary syndrome (ACS), heart failure, and cardiovascular mortality compared with non-diabetic individuals. The coexistence of diabetes and cardiovascular disease leads to more complex clinical courses and worse outcomes, particularly during acute hospital admissions to the Coronary Care Unit (CCU) \[1,2\].

Hyperglycemia during acute illness has long been recognized as a predictor of adverse outcomes in critically ill patients, including those with ACS. Stress-induced hyperglycemia results from increased counter-regulatory hormones, inflammatory cytokines, and insulin resistance, all of which are commonly present during acute myocardial ischemia. Numerous studies have demonstrated that elevated blood glucose levels at admission and during hospitalization are associated with increased morbidity and mortality in both diabetic and non-diabetic patients admitted to intensive and coronary care units \[3,4\].

In recent years, attention has shifted toward glucose variability (GV), which refers to fluctuations in blood glucose concentrations over time. Glucose variability includes both intra-day and inter-day glycemic excursions and is considered an important component of dys glycemia. Growing evidence suggests that glucose variability may have a more deleterious effect than sustained hyperglycemia by promoting oxidative stress, endothelial dysfunction, inflammation, and apoptosis, all of which play crucial roles in the pathophysiology of cardiovascular complications \[5,6\].

Experimental and clinical studies have shown that acute glucose fluctuations can induce greater oxidative stress than chronic stable hyperglycemia. These fluctuations are associated with endothelial damage, increased platelet activation, impaired autonomic function, and arrhythmogenesis, which may worsen outcomes in patients with acute coronary events \[7\]. In critically ill patients, increased glucose variability has been linked to higher rates of infections, prolonged hospital stay, and increased mortality, independent of mean glucose levels \[8\].

In patients admitted to the CCU, particularly those with diabetes, glucose control is challenging due to variable nutritional intake, use of vasoactive drugs, acute organ dysfunction, and insulin resistance. While current guidelines emphasize avoidance of severe hyperglycemia and hypoglycemia, they provide limited guidance on minimizing glucose variability. Several observational studies have suggested that higher glucose variability during hospitalization is associated with increased short-term and long-term mortality in patients with ACS and those requiring intensive care \[9,10\]. However, data specifically focusing on diabetic patients admitted to the CCU remain limited, and the independent contribution of glucose variability to morbidity and mortality in this population is not fully understood.

Understanding the relationship between glucose variability and clinical outcomes in diabetic patients during CCU admission is of great clinical importance. Identifying glucose variability as a modifiable risk factor could influence glucose management strategies, optimize insulin protocols, and ultimately improve patient outcomes. Therefore, this study aims to evaluate the association between glucose variability and morbidity and mortality in diabetic patients admitted to the Coronary Care Unit.

GV will be measure by random blood sugar of the patient during admission and calculate of mean blood sugar and standard deviation of random blood sugar.