Peripheral neuropathy, diagnosed with mild diabetes, but cannot explain for symptoms

[sonali_dey1]

Hi there- My 54 year old dad (Indian male, 78kg, 1.7m) has been suffering from a burning sensation on both soles of his feet for the past 10 months. About 3 months after the onset of symptoms, he visited a GP, and after blood tests it was confirmed that he did not have diabetes. Following that were multiple visits to Neurologists with nerve studies returning normal results, although a mild prolapse of the L4/L5 vertebra was observed. Finally, he was sent to an endocrinologist who diagnosed him with mild diabetes in November last year. He was put on medication and his diabetes is slightly better controlled now. I find it slightly unusual that even though since being diagnosed he has given up all simple carbs and sugar treats and has started to exercise every day without fail, his sugar levels are still barely normal.He exclusively has salads for lunch and dinner with a few carefully selected fruits. And sometimes his sugar levels still rise inexplicably. For instance, today after a 1 hour gym session, his blood sugar level was 9.9. His last proper meal was 8 hours ago, and he had 2 pieces of seaweed before heading to the gym- about an hour before the reading was taken. His medication has been changed twice (doubled in dose the first time- now 500mg/day, added Trajenta the second time) with little improvement. He currently takes Trajenta and Glucophage.

The most worrying part is the bilateral burning sensation that he finds unbearable sometimes. I understand that this is most likely due to nerve damage and could be irreversible, but I don't understand how it can manifest even with such mild diabetes- his highest reading even in the beginning stages of control was about 11-12mmol/L. Could there be another cause? It is probably also worth mentioning that he goes for regular health checkups and his mother having diabetes has put him on high alert and made him really wary of his health. He has been carefully controlling his diet and exercising regularly for the past few years. The endocrinologist himself has told us that it is not normal for individuals with diabetes as mild as my dad's to manifest with such neuropathy.

My dad will definitely continue controlling his diabetes, but please do advise us on whether there is another possible cause that could help with his symptoms. So far, he has not been losing any motor control in the affected area. He also has a few other issues- a left bundle branch block, high cholesterol, and high blood pressure. All controlled with medication. He recently had a knee surgery- about 1 month before the numbness manifested. He plays badminton every week, goes to the gym almost every day for an hour, and has a relatively desk-bound job in the electrical engineering sector.

Please help if you can. Thank you.