Effect of Conditioning Regimens on Glucose Metabolism in Children Undergoing Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation (HSCT) has greatly improved the survival of children with leukemia; however, long-term adverse effects remain a concern. This study aims to compare the effects of total body irradiation (TBI)-based and chemotherapy-based conditioning regimens on insulin resistance in children undergoing HSCT. Patients under 18 who underwent HSCT between April 2010 and October 2023 were evaluated. Seventy-six patients (M/F:48/28) with leukemia were included in this prospective descriptive cross-sectional study. Clinical and laboratory data, including oral glucose tolerance test (OGTT), were collected. The TBI group consisted of 45 patients with ALL (66.1%), and the non-TBI group consisted of 31 patients, including 23 with ALL and 8 with AML. The median time from HSCT to OGTT was 2.7 years (IQR, 1.8-3.8) and did not differ between the two groups. Body mass index and serum lipids, except HDL cholesterol, did not differ between the TBI and non-TBI groups. Twelve patients (26.6%) in the TBI group and 6 patients (19.3%) in the non-TBI group had impaired OGTT results (p > 0.05). All four obese patients had normal glucose tolerance. The TBI group had significantly higher peak and total insulin levels during the OGTT than the non-TBI group (p = 0.02, p = 0.02, respectively). Although HbA1c and HOMA-IR did not differ between the two groups, the Insulin Sensitivity Index (ISI) was significantly lower in the TBI group, indicating reduced peripheral insulin sensitivity (p = 0.04). TBI is a risk factor for reduced insulin sensitivity in pediatric HSCT survivors, which is a risk for type 2 diabetes and cardiovascular disease without leading to obesity.