Hypothesize a mechanism by which the glut4 transporter's fusion to the cell membrane could be decreased

GLUT4 is the transporter used for the transfer of the insulin and is coded by the gene SLC2A4 gene. This mainly acts as the insulin related glucose transporter.

The fusion of the GLUT4 with the cell membrane might decrease due to the unphosphorylation of the cytoplasmic domain of the insulin receptor even after binding with the insulin. The inability of the production of the secondary messengers because of unfolded or inactive enzymes. The improper functioning of the kinase proteins.  

the pic attached shows the stages of mitosis. hope it !