Association of serum leptin levels and pulmonary tuberculosis: a meta-analysis

Background: We performed a meta-analysis to investigate the association of serum leptin levels with the pathogenesis of pulmonary tuberculosis (PTB). Methods: The retrieval of related articles was achieved through searching the electronic databases according to strict inclusion criteria. The STATA version 12.0 statistical software was employed to calculate the standardized mean difference (SMD) and 95% confidence interval (CI) during the statistical analysis. Results: Twelve case-control studies were enrolled in this meta-analysis. Our finding showed that serum leptin levels of healthy controls were markedly higher than those of PTB patients (SMD = 0.70, 95% CI = 0.51-0.89, P<0.001). Stratified analysis based on ethnicity presented that lower serum leptin levels were apparently associated with the development of PTB among both Asians and Caucasians (Asians: SMD = 0.38, 95% CI = 0.15-0.61, P=0.001; Caucasians: SMD =1.54, 95% CI = 1.17-1.91, P<0.001). Furthermore, subgroups analysis based on the detecting method also showed that there was an association between the serum leptin levels and the development of PTB in both ELISA subgroup and RIA subgroup (ELISA: SMD = 1.03, 95% CI = 0.81-1.26, P<0.001; RIA: SMD = -0.41, 95% CI = -0.82 to -0.01, P=0.045). Conclusions: In conclusion, our present findings suggest that decreased serum leptin levels may be associated with the pathogenesis of PTB.