A interesting THEORY of action regarding lipid rafts in the cell membrane and the observed effects of both elevated blood glucose and seed oils, and possibly statins, in impacting insulin resistance (these seem like different things, but they seem to have similar outcomes). He goes over the theory at the 32 minute mark, before that he sets up background on the lipid system.

phospholipid bilayer is not a homogenous ocean of phospholipids, but is composed of islands of phospholipids (rafts) that float in the cell membrane, the lipid raft composed of large amounts of cholesterol and insulin receptors.

Depletion of lipid raft cholesterol detrimental to lipid raft function and impairing insulin receptor activation - leading to insulin resistance.

Anything that impacts that lipid raft/cholesterol function seems central to insulin resistance, and would link excess sugar intake and oil intake with insulin resistance as they both have demonstrated impact on these rafts.