Metabolic syndrome in hematologic malignancies survivors: a meta-analysis

The results from the published studies on whether the risk of metabolic syndrome is high among hematologic malignancies survivors are conflicting. The aims of this study are to conduct a systematic search and assess the literature to determine the available evidence on the association between metabolic syndrome and hematologic malignancies. Two reviewers independently conducted a systemic search to identify the available evidence from PubMed, EMBASE, and Cochrane database from database inception to June 4, 2014. The articles were limited to human studies and published in English. A combined analysis was performed, followed by a subgroup analyses stratified by the type of hematologic malignancies, hematologic malignancies treatment modality, criteria of metabolic syndrome, and individual components of metabolic syndrome. Publication bias was assessed using the Begg and Egger's tests and visual inspection of funnel plot. All analysis was performed using Stata SE version 10.0 software package. Seven cross-sectional studies with a total of 3,550 participants were included in the analysis. Compared with the healthy control groups, the hematologic malignancies survivors were at an increased risk of metabolic syndrome, in the random-effect meta-analysis of all seven cross-sectional studies (OR 2.03; 95 % confidence interval (CI) 1.23-3.35; I (2) = 43.9 %). In the subgroup meta-analysis by cancer treatment modality, a significant positive association was observed for hematopoietic stem cell transplantation (OR 2.40; 95 % CI 1.71-3.35). However, no significant positive association was observed for other major cancer treatment modality, including chemotherapy and radiation therapy. Further subgroup analysis by individual metabolic syndrome components showed that the risk of high blood pressure among hematologic malignancies survivors (OR 1.67; 95 % CI 1.10-2.53) was found to be higher compared with central obesity (OR 1.43; 95 % CI 1.02-2.01), whereas no significant association between hematologic malignancies survivors and other individual components including high glucose levels, high triglyceride levels, and low HDL cholesterol levels was observed. Funnel plot inspection and Begg and Egger's tests showed no evidence of publication bias for combined analysis. Our meta-analysis of studies showed that hematologic malignancies survivors were at an increased risk of metabolic syndrome.