Glycemic Variability Linked to Poor Outcomes in Heart Failure ICU Patients, finds study

A new study published in the journal of Nature Scientific Reports showed that elevated glycemic variability (GV) was independently associated with higher short-term mortality and longer ICU stays in critically ill heart failure patients, highlighting the need to control blood glucose fluctuations for better outcomes and reduced healthcare burden.

Heart failure (HF), which is defined by the heart's diminished capacity to efficiently pump blood, is a significant worldwide health concern. Insufficient metabolic supply results from either diastolic dysfunction, in which the heart does not fill sufficiently, or systolic dysfunction, in which the heart's contraction is compromised.

The standard deviation or coefficient of variation are frequently used to quantify the fluctuations in blood glucose levels, which are referred to as glycemic variability (GV). Because of its connection to inflammation and oxidative stress, GV is becoming more well acknowledged for its possible effects on cardiovascular health. In critically sick heart failure patients, this study investigates the relationship between glycemic fluctuation and short-term mortality.

Almost, 23,744 individuals with heart failure were among the data reviewed from the Medical Information Mart for Intensive Care (MIMIC-IV) and the eICU Collaborative Research Database (eICU-CRD). The coefficient of variation of glucose levels throughout an intensive care unit stay was used to quantify glucose variability, which was then divided into quartiles.

Associations with in-hospital and 30-day mortality were evaluated using multivariable logistic regression and Cox proportional hazards models. The connection with length of stay in the intensive care unit was assessed using linear regression models. Restricted cubic splines were used to investigate dose-response correlations.

The 30-day death rate was 17.6% while the in-hospital mortality rate was 15.0%. 3.1 days was the median length of stay in the intensive care unit (IQR: 1.9–5.4). The risk of 30-day death (HR: 1.37, 95% CI: 1.23–1.53) and in-hospital mortality (OR: 1.77, 95% CI: 1.54–2.04) was substantially greater for patients in the greatest glycemic variability quartile than for those in the lowest quartile.

Furthermore, longer ICU stays were linked to increased glycemic variability; after controlling for variables, each unit increase resulted in a 2.57-day extension (95% CI: 2.03–3.10, P < 0.001). In-hospital mortality showed a U-shaped link, but 30-day mortality showed a linear relationship. Subgroup and sensitivity studies validated the strength of these results.

Overall, elevated GV was substantially linked to both 30-day and in-hospital mortality, suggesting that it may be a crucial clinical metric that has to be regularly watched over and controlled in the intensive care unit. These findings imply that regular GV monitoring and management may be essential to enhancing patient outcomes, especially for individuals with serious cardiovascular diseases.

Reference:

Liu, P., Li, Z., Tang, S., Dou, W., & Liu, Y. (2025). Association between glycemic variability and mortality in critically ill patients with heart failure. Scientific Reports, 15(1), 1–12. https://doi.org/10.1038/s41598-025-16212-0