Hi! I have measures from an epigenetic variable from two different groups (Treatment and control) measured in two different tissues. I have identified differences for this epigenetic variables between Treatment and control groups (Group) in each tissue separately, splitting my data into two subsets (one for each tissue) using the following models in R:
model_tissue_1 <- lm(Epigenetic_variable ~ Group + Age + Sex + Cell_proportion_1 + Cell_proportion_2 + Cell_proportion_3 + Cell_proportion_4, data = my_data_tissue_1)
model_tissue_2 <- lm(Epigenetic_variable ~ Group + Age + Sex + Cell_proportion_1 + Cell_proportion_2 + Cell_proportion_3 + Cell_proportion_4 + Cell_proportion_5 + Cell_proportion_6 + pH, data = my_data_tissue_2)
Please note that each model includes different cell proportions as covariates, according to the studied tissue. Also, model_tissue_2 includes an additional covariate that was not measured in the other tissue (pH).
Now, I would like to evaluate cross-tissue differences for the Epigenetic_variable among the groups, i.e., to identify Epigenetic variable differences between tissue_1 and tissue_2 for individuals in the Control group, as well as in the Treatment group, if possible considering all the covariates from each model. Is there a way to do this?