Statistical analysis
For raw data presented as the median and range or the median and interquartile range, the data were transformed to speculate the mean and standard deviation24 .
The pooled standardized mean difference (SMD) and its 95% confidence interval (CI) were used to assess the resistin in patients and healthy controls. Moreover, Cochran Q-statistic was applied to evaluate the heterogeneity among the included studies, andI 2 test was applied to further evaluate the extent of heterogeneity. When heterogeneity existed among studies (p < 0.05 for the Q test or I 2> 50%), a random-effect model was used; otherwise a fixed-effect model was utilized. Meta-regression and subgroup analysis were used to explore the possible sources of heterogeneity. The sensitivity analysis was conducted by removing any single study at a time to assess the reliability of the results. Egger’s weighted regression were used to estimate potential publication bias. A two-tailed p < 0.05 were deemed statistically significant. All statistical analyses were performed by R (version 3.6.0) software.