What Causes Sensational-less In Body Parts While Having Diabetes?

respected sir,my aunt is living in mumbai and is 48 yrs in age she is suffering from diabetes from last 10 yrs and is on regular insulin dosage from last 6 yrs, recently she loss power in her legs and cant even feel anything in her legs and slowly she is losing power and sensation of her hands also,even after taking all precautions sometimes her diabetic level goes above normal,her ecg is normal,we had consulted everywhere but to no avail,we need your guidance immediately

thankyou
jagjeet singh