Under chronic hyperglycemia, endogenousTNF-α production is accelerated in microvascular andneural tissues, which may undergo an increased microvascularpermeability, hypercoagulability, and nerve damage,thus initiating and promoting the development of characteristiclesions of diabetic microangiopathy and polyneuropathy.Enhanced TNF-α production may also promoteatherosclerosis due to increased insulin resistance and theexpression of adhesion molecules. This evidence concerns the gene TNF and polyneuropathy.