Metabolic syndrome and the incidence of lung cancer: a meta-analysis of cohort studies
Qiao Li, Deliang Ma, Hui Lv, Ding Shi, Min Fei, Yú Chen, Fei Xie, Zhuoyan Wang, Ying Wang, Wanhua Liang, Peiying Hu
Abstract
Abstract Background Metabolic syndrome (MetS) has been related to the pathogenesis of variety categories of cancers. This meta-analysis aimed to determine the association between MetS and the incidence of lung cancer. Methods Relevant cohort studies were identified by search of PubMed, Embase, and Cochrane’s Library databases. Cochrane’s Q test and I 2 statistic were used to analyze the heterogeneity. Random-effect model which incorporates the potential heterogeneity was used for the meta-analysis. Results Five cohort studies with 188,970 participants were included. A total of 1,295 lung cancer cases occurred during follow-up. Meta-analyses showed that neither MetS defined by the revised NCEP-ATP III criteria (hazard ratio [HR]: 0.94, 95% confidence interval [CI]: 0.84 to 1.05, p = 0.25; I 2 = 0) nor the IDF criteria (HR: 0.82, 95% CI: 0.61 to 1.11, p = 0.20; I 2 = 0) was associated with an affected risk of lung cancer. Subgroup analyses showed consistent results in women and in men, in studies performed in Asian and non-Asian countries, and in prospective and retrospective cohorts (p all > 0.05). Meta-analysis limited to studies with the adjustment of smoking status also showed similar results (HR: 0.91, 95% CI: 0.80 to 1.05, p = 0.21; I 2 = 0). No publication bias was detected based on the Egger regression test (p = 0.32). Conclusions Current evidence from cohort studies does not support that MetS is an independent risk factor for the incidence of lung cancer.