[BioC] edgeR : How to associated trait with DE?

[Sermsawat Tunlaya-anukit]

Can i associated trait into edgeR result? I have quantitative traits such as height in each library that would like to find gene that co-regulate or co-expression with that trait. How can i apply this into edgeR? Can i use $psedo.alt to calculate correlation with my trait? Or i should GLM to calculate DE that associated with trait? I am not sure how to apply my trait into design or another vector and calculate estimateGLMCommonDisp. 

Thank in advance,
Sermsawat Tunlaya-anukit