Impact of being overweight on outcomes of hematopoietic SCT: a meta-analysis.

The impact of being overweight on outcome after hematopoietic SCT (HSCT) is controversial. We performed meta-analyses to evaluate the impact of being overweight on acute graft-versus-host disease (aGVHD) risk and survival. Original data were obtained from MEDLINE, and studies that evaluated being overweight before transplantation in recipients as a risk factor for aGVHD or a prognostic factor for overall survival (OS) were extracted. Study-specific relative risks on the log scale comparing overweight with non-overweight patients were used to obtain a pooled RR with 95% confidence interval (CI). We identified 8 studies of aGVHD and 21 of OS. In allogeneic HSCT, the meta-analysis determined statistically significant associations of overweight recipients with aGVHD risk and OS. Meta-analysis of the 8 studies of aGVHD indicated that the RR for overweight to non-overweight patients was 1.186 (95% CI: 1.072-1.312). Regarding OS, meta-analysis of 11 allogeneic HSCT studies indicated that the RR for overweight to non-overweight patients was 1.163 (1.009-1.340). Our results indicate that being overweight before transplantation in recipients is associated with a high aGVHD rate and worse survival after allogeneic HSCT. Potential heterogeneity especially in adult/pediatric patients limits the interpretability of our finding. Further, well-designed large cohort studies are warranted.