A 62-year-old patient with long-standing Type 2 diabetes mellitus and poorly controlled hyperglycemia complains of numbness and tingling in his feet that has progressed to his hands in a "stocking-glove" distribution. He also reports lightheadedness upon standing and erectile dysfunction. What is the most likely underlying mechanism causing these symptoms?
✓ Correct Answer: Option C
Diabetic neuropathy results primarily from chronic hyperglycemia leading to microvascular damage, oxidative stress, and accumulation of advanced glycation end products, which cause axonal degeneration and demyelination of peripheral nerves.