My diabetes nurse has also told me to go to bed having a blood sugar of, at least, an 8 and I believe that this is a good advice.
Here is my thinking why I believe that this advice is good.
I hear about diabetics who can achieve this wonderful numbers, where they go to bed at a 5 or a 6 and their fasting is around the level. This is brilliant! However, what they are not telling us, sometimes, is the rest of the story, which goes like this:
1. They are men so, they do not have to persevere the insecurity of hormonal imbalances that can happen to us women (not only during the month but also during 24hrs.)
2. They are women who have been through menopause so, they have no hormonal imbalances coming to play.
3. They are of age 50-60+, they may not work and have a very sedentary lifestyle, having no other responsibility really other than watching telly and checking their blood glucose every one hour or so.
4. They are on a pump hence, can adjust their insulin needs very frequently.
Or, they may have a general sedentary lifestyle and have chosen to not challenge their diabetes in anyway. I have a friend like that… She does office work, does not exercise, takes her car to go everywhere, spends evening on a couch watching telly and has her groceries delivered… Obviously, she can have the luxury and can take a risk to sleep having a blood sugar of 6mmols considering her background insulin is calculated correctly. On the contrary, I met on the DAFNE course (that I attended recently) a diabetic who is training for the London marathon. He lowers his insulin intake before and after his exercise and he has a Mars bar prior exercise or jelly babies during exercise to keep him leveled... he still gets nocturnal hypoglycemias despite he is adjusting his insulin and is treating during exercise.. I hate to imagine what would happen if his pre-bed blood glucose was 5 mmols...
I am not suggesting that there aren't any diabetices out there who do manage the fantastic levels we have in mind. I am certain they are but, it takes a lot of practice and artistic insulin handling to achieve it.
And then, there are people like myself where many, many factors can affect our blood sugar.
Hormonal imbalances, activity and exercise (even running after your kids or playing with them can be considered an exercise) stress at work or at school (exams, bullying, etc.), delayed onset hypoglycemia from exercise, weather conditions, altitude when travelling, air cabin pressure when flying (which tends to drop blood glucose like a stone) and a bunch of other things which don’t came to mind at the moment.
Also, you may not be on a pump… so, once you inject your insulin… that’s it, it’s in there.
Therefore, a blood glucose of 8mmols is a nice and safe number (considering that you will also check overnight.) Plus, I saw at your profile that you are a lovely young lady and, I assume, you want to enjoy your life, have fun, party, be sociable, have sex

, travel etc.
I am on Levemir twice a day. My evening Levemir is well balanced and usually keeps me leveled. Yesterday late afternoon I had some (un-intended) activity (Christmas shopping with a friend). I usually have delayed onset hypoglycemia (so I see the effects of exercise, at least, 5 hours after I finish activity). I went to bed at 24:00 with an 11.8
03:00 I was at a 9.1
Fasting was 5.8 and dropping (according to my Freestyle Libre)
I don’t want to think what kind of a night I would have if I went to bed at a level of 5-6mmols as some diabetics are suggesting.
What I suggest, instead, is to listen what people say but, choose to do what is the safe thing for you.
Love and hugs and wishes for a season full of merriment!
Regards
Josephine