2.4. Statistical study
The data are presented as the mean SD. The hypothesis
contrast between two samples was done with the Student t test. For
more than two samples the comparison was made with one- or
two-way ANOVA and the post hoc analysiswas done with Duncan’s
multiple range tests. The probability (Odds Ratio) of an event was
calculated with multiple logistic regression models. In all cases the
level of rejection of a null hypothesis was P 0.05. The statistical
analysis was done with SPSS (Version 11.5 for Windows; SPSS,
Chicago, IL).