Statistical analysis
The Skewness index and q-q-plot were used to evaluate the normality of variables. The intergroup comparison was done with paired t-test and the between-group comparison was done with an independent t-test. Between-group comparisons for qualitative traits were performed based on the chi-square test. Between-group comparisons were performed to control for confounding factors through analysis of covariance (ANCOVA). Data were reported as mean ± standard deviation (SD) or frequency (percentage). Statistical data analysis was done using SPSS22 software. A 