I'll set my meter alarm if I start to have night-time hypo's or I am waking with high morning readings, my reason for testing is to establish if my basal insulin is set at the correct dose.
I regularly test at 2.30 - 3.00am every night, reason being I'm having difficulty in avoiding night time hypos and early morning highs - it's a real pain. Seems to be no one answer either - sometimes having carbs before bed helps, but other times seems to make no difference and I go low and other times it send me too high. I'm hoping that my pump, which I'm meant to have soon (?!), will help sort this out.
I used to set alarm to test at 3am because like Riri my sugars during the night would be unpredictable, i would have some supper (toast) and some nights I would go low wheras the following night (similar foods and exercise throughout the day) i would go high. I have just started on the pump now and am required the 3am testing to make sure i am having the correct insulin, currently doing it about 3 or 4 times a week but hopefully will be able to cut this down to 1 or 2 times a week soon.
Only when I'm doing a over testing session to check out my basal are still correct or whether I may need tweaking or not..
Pre-pump days I did suffer night-time hypo's which I would regularly sleep through once I got my pump a lot of this was resolved..
Now I've lucky to have a German Shepherd who will wake me in the night if she senses my BG started dropping... She can pick them up around the 3.7mmol/l mark
But what I do if for any reason I wake up in the night, I always take a test
I will test if I have eaten late and may need to make a correction.. for instance I am home late eat at 8 - 10 pm... I test 2 hours post meal and then need a correction... I would then test 1 - 1 1/2 hours later just to check I didn't over-correct...
Once every two weeks on a Friday night I test every 2 hours... just to make sure basal is correct.
Finally! I have a five - month old daughter who although mostly sleeps through the night doesn't always... if I am up in the night with her then I will take the opportunity to test.