24 Ischemia was evoked by inflation of the arm cuff to 200 mm Hg during 5 minutes. Blood pressure was measured on the left arm by the auscultatory method, using a calibrated mercury sphygmomanometer with an appropriate cuff size, once at the beginning of preischemia FBF measurement and once at the beginning of postischemia FBF measurement. FBF was calculated by a semiautomatic method, which has shown high intra- and interevaluator reproducibility (intraclass correlation coefficients between 0.98
and 0.99).25 Mean blood pressure (MBP) was used to calculate forearm vascular conductance (FVC; FBF/MBP). Thereafter, the area under the FVC curve was calculated pre- and postischemia. The percent increase in area under the FVC during postischemia, above the correspondent area under the FVC during preischemia, was considered as the Epacadostat in vitro study’s vascular reactivity measure and used as the main end point INNO-406 cell line for statistical analyses. The sample size was estimated on the basis of
pilot data and results from previous studies.12 and 13 For a 2-way analysis of variance (ANOVA) (2 groups and 4 repeated measures), a total sample size of 120 subjects would be necessary to detect a difference of 35% between groups’ vascular reactivity (group main effect), considering a standard deviation within groups of 90%, P value of 0.05, and power of 0.80. Shapiro–Wilk’s test was used to verify variables’ distribution, Pregnenolone Levene’s
test was used to verify homoscedasticity, and Mauchly’s test was used to verify sphericity. Some variables were not normally distributed (ie, age, BMI, triglycerides, HDL, glycemia, VO2peak, SBP, and vascular reactivity), and thus were transformed into natural logarithms for inferential analyses. After logarithm transformation, there was no violation of the homoscedasticity assumption in any analyses. Nonetheless, vascular reactivity results deviated from the sphericity assumption, which required a correction that is described next. Three genetic models (dominant, recessive, and additive) were assessed to verify which model was better to fit the vascular reactivity data on partial correlations adjusted by all sample characteristics. In these partial correlations, eNOS gene polymorphisms were analyzed as dummy variables as follows: dominant model (heterozygous + polymorphic homozygous = 0 vs wild homozygous = 1), recessive model (polymorphic homozygous = 0 vs wild homozygous + heterozygous = 1), and additive model (polymorphic homozygous = 0 vs heterozygous = 1 vs wild homozygous = 2). Then, subjects’ characteristics according to genotypes and haplotypes were compared using independent Student t test or chi-square test.