Abstract
Obesity and diabetes can modulate immune responses, which may impact allogeneic HCT outcomes and GvHD. From the EBMT registry, we included 36,539 adult patients who underwent allogeneic HCT for a hematological malignancy between 2016 and 2020. Of these, 5228 (14%) had obesity (BMI ≥ 30 kg/m(2)), 1415 (4%) had diabetes (requiring treatment with insulin or oral hypoglycemics), and 688 (2%) had obesity + diabetes pre-transplantation. Compared with patients without diabetes or obesity, the hazard ratio (HR) of grade II-IV acute GvHD was 1.00 (95% confidence interval [CI] 0.94-1.06, p = 0.89) for patients with obesity, 0.95 (CI 0.85-1.07, p = 0.43) for patients with diabetes, and 0.96 (CI 0.82-1.13, p = 0.63) for patients with obesity + diabetes. Non-relapse mortality was higher in patients with obesity (HR 1.08, CI 1.00-1.17, p = 0.047), diabetes (HR 1.40, CI 1.24-1.57, p < 0.001), and obesity + diabetes (HR 1.38, CI 1.16-1.64, p < 0.001). Overall survival after grade II-IV acute GvHD was lower in patients with diabetes (HR 1.46, CI 1.25-1.70, p < 0.001). Pre-transplantation diabetes and obesity did not influence the risk of developing acute GvHD, but pre-transplantation diabetes was associated with poorer survival after acute GvHD.