A 46 years old patient with normal body weight and height, having blood sugar fasting 100 -114 mg and pp 140 - 144 mg. From last two years, he is checking blood sugar level in every 3 months. But whenever random blood sugar is checked it comes always 180 -239 mg. His both parents are diabetic.

He c/o of palpitations only. What is this phenomenon? Is there any explanation?