As per your explanation I understand there are two issues. First is left leg imbalance and not able to give weight in it. Second is high blood sugar. For sugar patient it is common when ever there is some thing wring in body along with inflammation the first thing is sugar level goes up. But it can also be normally with out any cause so first thing you need to do is maintain his diet and blood sugar level through insulin or which ever way possible. If needed do visit your diabetologist for further treatment. Next you have mention he is not able to balance or give weight on one of his leg. But you have not mention what exactly happens when he gives weight on leg. Is it due to pain or loss of control. Let s assume if its pain. Now pain in leg can be due to some injury where he might have hit his leg some were and he Don t remember or it can be due to reduce blood circulation also. Here I suggest patient need to visit a orthopedic doctor and go ahead with proper examination and evaluation and plan treatment as per that. If there is too much pain at leg then patient can use hot pack as well apply a crep bandage to stabilise the soft tissue. This will help for getting some pain relief but remember this will not cure the pain. So do visit doctor as early as possible. If its loss of control then also you need to evaluate it properly why its happening. It may be possible due to age also. But further evaluation as well conformation can be done only on examination so I suggest to check with doctor again for this. I am sure this will be useful for you if you follow the given advice properly. Take care.