2.6. Statistical analysis
SPSS 17.0 for Windows (IBM, Chicago, IL) was used for the data analyses. Results were expressed as arithmetic means ± standard error of the mean (SEM). The normal distribution of variables and the homogeneity of variances were verified by the Kolmogorov–Smirnov and Levene’s tests, respectively. The ANOVA and Kruskall–Wallis tests were used for comparisons of parametric and non-parametric data, respectively. p < 0.05 was considered significant.