Statistical analysis was performed using the SPSS software package (SPSS Inc. Chicago, IL). Analysis of statistical significance for BMD and vertebral strength data was performed by One-Way ANOVA and Tukey’s HSD multiple comparison procedure. Significance was noted at p ≤ 0.05. Multiple regression analyses were used to determine the relative contributions of body weight versus treatment condition on the effects observed in the dependent variables (BMD, strength) we studied. These analyses were performed in a 2-step hierarchical fashion. Information about treatment groups was carried by 3 dummy coded dichotomies to account for the 4 treatment conditions. All regression analyses were conducted in a similar fashion. First, the dependent variable was regressed upon post-treatment weight. Next, the treatment group dichotomies were added to the equation. The adjusted R2 was measured in each step and the change in this statistic was tested for significance. The change in adjusted R2 indicated the percent of variance that was explained by treatment group after accounting for the variability due to weight.
