Blood sugars rising in the night

[CarlyB]

Hi everyone,

My DSN recommended I test my BGLs at 3am for a while. I have since noticed that they rise by about 1-2mmols between bedtime and 3am. Not massively high - the highest being 9.7mmols. Then drop by anywhere up to 3mmols by the time I wake up.

Is this normal?

TIA

 

[GrantGam]

The 1-2mmol/l rise isn't anything to be concerned about, especially if it returns to a normal reading when you wake. I think it says in the "Think Like A Pancreas" book that your basal dose is set correctly providing that your bed time reading and waking readings are within 1.7mmol/l of each other.

The reason why you shouldn't be overly concerned about your BG rising and falling by those wee values you've described - is because BG values are non-linear. By non linear I mean that it's extremely difficult to have a flat basal profile overnight. It is achievable, but not by everyone - especially when on MDI. There are many things that can impact overnight BG such as diet, exercise, hormones, sleep patterns, etc.

It's worth noting that basal insulin (I'm speaking about Levemir in this instance, because it's all I've ever used) takes time to kick in after injecting - 5hrs for this insulin. So if I were to inject at 10pm, it would not start working till 3am - depending when you take your basal injection, this may also be what you're experiencing.

Further to the above, most "once daily" basal insulins don't last 24hrs. So without a split dose, it's common to notice a gradual BG rise anywhere between 16-24hours post injection.

 

[CarlyB]

Thanks that's really helpful. I inject my levemir at 10pm too so that makes sense.