Hyperglycaemia as a predictor of morbidity and mortality in patients receiving an allogeneic haematopoietic stem cell transplantation

Summary Allogeneic haematopoietic stem cell transplantation (allo‐HSCT) is an effective treatment for patients with haematological malignancies; however, post‐transplant complications, including infections and acute graft‐versus‐host disease (aGvHD), remain significant issues. Identifying modifiable risk factors is therefore critical to improve patient outcomes. This retrospective study evaluated the impact of hyperglycaemia on post‐transplant outcomes in adult patients undergoing allo‐HSCT at the University Medical Centre Groningen between 2018 and 2024. Hyperglycaemia was defined as a glucose level exceeding 10 mmol/L in capillary or venous samples. In total, 575 patients were included. The median age was 61 years (interquartile range [IQR]: 52–68); 64% were male, and the median body mass index (BMI) was 25.3 kg/m 2 (IQR: 23.1–28.0). During hospitalization, 26.6% of patients experienced at least one episode of hyperglycaemia. After adjusting for confounding variables, hyperglycaemia was associated with significantly reduced 100‐day overall survival (hazard ratio [HR] 2.36, 95% confidence interval [CI] 1.29–4.33). It was also linked to an increased risk of severe (grade ≥3) aGvHD and infections. Importantly, hyperglycaemia occurring within 30 days prior to transplantation already predicted poorer survival. In conclusion, hyperglycaemia at any moment during allo‐HSCT is predictive for treatment‐related adverse events. Since glucose levels are highly modifiable, closer attention and timely intervention might improve outcomes.