Late Effects of Allogeneic Hematopoietic Stem Cell Transplantation in an Asian Patient Population

BACKGROUND : Long-term survivors of allogeneic hematopoietic stem cell transplantation (alloHSCT) are at a substantial risk of developing medical late effects. We aimed to determine the incidence of metabolic syndrome (MS), cardiovascular (CV) events, bone density loss, and fractures in a cohort of patients who underwent alloHSCT for hematologic disorders. The potential risk factors for MS, CV events, bone density loss, and fractures, as well as the sufficiency of existing monitoring measures in our institution, were also evaluated. METHODS : A single-center, retrospective study was conducted. We included patients who underwent alloHSCT at the Singapore General Hospital between January 2011 and December 2016, were at least 21 years old, and had a minimum follow-up period of 6 months. Patients with MS-related data comprised the CV study population, whereas patients with bone loss-related data comprised the skeletal study population. Associations between risk factors and the development of MS or bone loss were assessed using a univariate analysis followed by multivariate logistic regression. All analyses were performed using SPSS version 23. RESULTS : A total of 91 patients were included in the CV study population, of which 13 (14.3%) had preexisting MS, 17 (18.7%) developed MS, and 5 (5.5%) developed CV events after alloHSCT. Thirty-one patients were included in the skeletal study population, of which 2 (6.5%) had preexisting bone loss, 23 (71.0%) developed osteopenia or osteoporosis, and 2 (6.5%) had a fracture. After adjusting for preexisting MS, pretransplant abdominal obesity (p=0.002), elevated triglyceride (p<0.001), and fasting hyperglycemia (p<0.001) significantly predicted MS on multivariate analyses. Only female sex predicted the risk of bone loss after alloHSCT on multivariate analyses after adjusting for preexisting osteopenia (p=0.02). Of the 174 patients who underwent alloHSCT during the study period, 83 (47.7%) and 143 (82.2%) patients had no MS-related data and bone loss-related data, respectively. CONCLUSION : Long-term alloHSCT survivors are at an increased risk of MS, CV complications, and bone loss. This underscores the importance of close monitoring and timely interventions to reduce long-term morbidity and mortality.