2.15 | Data and statistical analysis
The data and statistical analysis comply with the recommendations of theBJP on experimental design and analysis in pharmacology (Curtis et al., 2018). All studies were designed to generate groups of equal size, using randomization and blinded analysis. Group size is the number of independent values, and statistical analysis was carried out using these independent values. Sample sizes in each group subjected to statistical analysis were determined based on our previous studies, preliminary results, and power analysis (Curtis et al., 2015). Statistical analysis was undertaken only using these independent values with n ≥ 5. Fold change over control was used in Western blot and gene analysis to avoid the larger variation among different experiments. The mean values of the control group were normalized to 1. In the figures, the Y axis shows the ratio of the experimental group to that of the corresponding matched control values and is labelled as “fold matched control values.” All results were expressed as mean ± SEM. Statistical analysis was performed using GraphPad Prism 7.00 (RRID:SCR_002798 , http://www.graphpad.com/). Unpaired Student’s t test was used to analyse data from two groups. Differences among multiple groups were analysed by one-way ANOVA with Bonferroni post hoc analysis. Chi-square test was used to analyse the composition of aneurysm, the elastin degradation, and the incidence of aneurysm. Survival rate was noted in Kaplan-Meier analysis and comparisons were performed using the log-rank test. For angiotensin II-induced aortic aneurysm, data analysis (survival rate, incidence, elastin degradation, number of aneurysms) was performed on 11 mice in each group. In the characteristic analysis of aneurysms (diameter, area, length, collagen deposition), mice died of ruptured aneurysms (4 SKI mice treated with solvent control) and mice without aneurysms (3 WT mice treated with solvent control and 2 SKI mice treated with pioglitazone) were excluded. For determining whether groups differ, the level of probability was set at P < .05 to constitute the threshold for statistical significance.