A 60 year old man presents with numbness of both feet for 2 months.

He was diagnosed with type 2 diabetes mellitus 6 years ago, which is well controlled on Metformin alone. His medical history is otherwise unremarkable.

He consumes a mixed diet and only drinks socially.

His HbA1c is 6.0%, while a recent full blood count and serum creatinine were normal.