Obesity is associated with higher overall survival in patients undergoing an outpatient reduced-intensity conditioning hematopoietic stem cell transplant.

BACKGROUND: The impact of obesity on hematopoietic stem cell transplantation (HSCT) outcome remains controversial and has been considered a relative contraindication for the procedure. We investigated the influence of Body Mass Index (BMI) on the clinical course of adults undergoing an ambulatory HSCT after a non-myeloablative conditioning regimen.
METHODS: Adults with hematologic diseases undergoing an autologous or allogeneic HSCT after reduced intensity conditioning (RIC) and supported exclusively with enteral nutrition (EN) were studied. BMI and body fat were sequentially determined. Patients were divided into three BMI subgroups: underweight; normal, and overweight/obese.
RESULTS: Seventy-seven patients with a median follow-up of 21months were evaluated. Fourteen (18.2%) were underweight, 21 (27.3%) had a normal weight, and 42 (54.5%) were overweight/obese. A significant weight loss was observed among all three weight groups after HSCT (P=0.014). No correlation was found between time to engraftment and BMI (P=0.91), serum albumin (P=0.387), and fasting glucose (P=0.64), nor between BMI and acute (P=0.456) or chronic (P=0.209) graft versus host disease (GVHD). On multivariate analysis a higher overall survival (OS) was documented for obese patients (P=0.037). DISCUSSION: A BMI >30/kg/m(2) was independently associated with a higher survival rate after HSCT. Obese patients should not be excluded as transplant candidates based only on this parameter.