A fasting glucose test will give a fairly accurate reading of the amount of excess glucose floating around your blood streams. A measurement of 5.0 mmol/l is considered normal, not diabetic.
thanks for that but does not answer question about whether the level will increase or decrease from random(non fasting).
We need to have some clarification. Your first question asked about an increase or decrease while fasting (prandial) - "nothing to eat approx 9 hours beforehand". I answered this question with what is considered the normal value, 5.0 mmo/l. I apologize if this was insufficient information. However, between 4.0 to 5.0 mmo/l fasting is your goal. There are too many unknowns to make a determined guess as to whether your glucose will increase or decrease because lifestyle is a major contributing factor.
To answer your latest question "whether the level will increase or decrease from random(non fasting", the answer is yes, increases after meals. See this link for a full explanation on diabetes.