My uncle have had diabetes for over 40 years. Mostly it was under control. Recently over the last year his sugar levels have been fluctuating. Now in the last 3 days they have been gradually increasing and today fasting was 269 mg/dl and PP was over 520 mg/dl. He takes insulin and increased it by 2 units in the last 3 days. Still sugar level not coming down. Possible reasons and recommended treatment?