Reducing Overnight Level

[Mark T]

I appreciate some people would be happy with were my readings are 😉

I've noticed that my before bed readings and my waking readings both average about 6.6 mmol/L so I decided to try do a middle of the night reading to see where it is. Last night our little boy woke us at 3:30am - so I took a reading and it was 6.7 mmol/L (I need to repeat this a few more times).

My assumption was that my levels would drop slightly over night, although my body and brain are at rest (and thus not burning huge amounts of glucose) because my level was about the normal point (~5mmol/L) my pancreas would still be producing background insulin to remove the extra glucose.

So my question, does anyone else see similar types of behaviour - where they hold there level overnight and is my assumption that I should continue to drop correct?

I know I can go lower as my daytime pre-meal levels are often in the 5.x range. My suspicion is that my overnight levels are not driving my HbA1c so in order to reduce my HbA1c I would need to reduce them.

My last snack is usually somewhere between 8 and 9pm, and is usually a Nairns biscuit (mid GI, 6gC) with some cheese. Bedtime readings are ~10:30pm, Waking is ~7am.

 

[Robster65]

Hi Mark.

I can't really help with your queries, but I'm happy to bump your post up in case someone else can.

I would have thought that your liver is secreting a small, consistent amount of glucose overnight, so your pancreas only has to cover that and maybe a small amount extra for your supper. It probably almost manages to cover this so doesn't fluctuate much, but can't quite get it down to the 4s and 5s. This is just a guess of course.🙂

My only suggestion would be to try going for a brisk walk before bedtime or find some other form of exercise to get your metabolism speeding up through the wee hours and it may lower it further.

Rob

 

[trophywench]

I can answer this because I read it elsewhere not long ago - it's apparently 'normal' to have a variation (ie up or down) of up to 1.7 overnight.

If it goes up more it's 99x out of 100 DP and if down more, too much insulin.

Been diabetic nearly 40 years and I still learn summat new almost every day!

 

[shiv]

I heard a speech by Dr Fiona Campbell (paed diabetes, Leeds) last year. She said that in a non diabetic, levels overnight are often seen to go right down to the 4mmol-mark and stay there all night as the brain and body 'shut down' overnight. She didn't mention a dip over night, but she did specifically say that non d's often go down into and stay in the 4s all night. Sorry if that just confuses things? I guess I'm reading between the lines in what she said!

 

[Robster65]

That's what I would expect Shiv. A drop because your body isn't likely to be active, but then a steady line through to the dawn rise.

If your BG is in the 6s, there's obviously room for improvement, but no idea how you would acheive that apart from more exercise in the evening or more/different meds.

A drop certainly often occurrs in T1s, but T2s are slightly different if they have some pancreatic function. Although the BG may be higher than it should be, it shouldn't normally drop unless meds bring it down. I would have thought. 🙂

Rob

 

[everydayupsanddowns]

I thought there was a drop in the output of some hormones (cortisol?) that stimulate glucose release overnight. Hence risk of overnight lows/reduced overnight basal Probably, like everything, it varies from person to person.

 

[Ellie Jones]

It could be that from the 10.30pm to the 3.30am reading you've actully gone up and started to drop back down again and the lowest ebb for your homone activity could be later and near the 4am!

In general the lowest ebb of hormone activity is around 2-3am but as with everthing diabetic wise it's all individual and some will fall outside of the general slots...

Nightshift workers are generally more able to pin point their lowest ebb of hormone activity, as it will be the point of the night shift where they struggle the most to stay awake and feel able to work..

I would keep testing at verious time throughout the night when you can, you might build enough of a picture over time to pin point your lowest ebb

 

[Mark T]

Thanks for all your replies 🙂 although I was hoping for a few of the Type 2's to chip in 🙄

The issue basically comes down to what the likely cause of the higher overnight levels are. My understanding was that in a non-diabetic the pancreas would produce insulin to take the body down to a quiescent level (as stated by Shiv).

In a Type 2 diabetic, from what research I have read there can be a few mechanisms;

• Insulin Resistance

• Raised Liver Glucose production

• Glucokinase - affects the level at which insulin secretion is triggered

There are probably a few more that I haven't discovered yet, and I don't fully understand exactly what Insulin resistance will do.

In theory my metformin should be reducing the first two. The second item is MODY2 primarily and I'm pretty sure that isn't me (I have some similarities to MODY3, but I lack the "normal" age of diagnosis and the low renal threshold).

As to what I can do about it, well I could lowering my supper/snack carb loading (not ideal it's not that high anyway). Or I could do some more exercise, but it would have to be high impact exercise - aerobics or weight training since the fast walking I do at lunchtimes does not impact bg levels (but does weight loss really nicely).

But if my body can't drop my bg levels overnight, I'm more wondering if my medication needs to be adjusted as well.

 

[HelenM]

Overnight levels don't vary by much in people without diabetes.

This graph (press pause)
http://www.diabetes-symposium.org/index.php?menu=view&source=&sourceid=0&id=322&chart=18
shows the daily continuous BG readings for a group of 21 non diabetics.(blue line is the average, brown lines show the range to 2sd)
The last meal was at 6pm but it isn't until 6 hours later at midnight that the lowest level was reached and then the levels stay about the same for the rest of the night( the mean level overnight was around 80mg/dl(4.4mmol/l)

If you look at the larger scale graph for 3 different nights, then there is a bit of variation with very a slight drift downwards overnight and levels starting to rise at about 6.30am but the variations are very small.
http://www.diabetes-symposium.org/index.php?menu=view&source=&sourceid=0&id=322&chart=24

I wonder what your glucose levels would be without the evening snack?

 

[Mark T]

Thanks for a bit more information HelenM 🙂

...I wonder what your glucose levels would be without the evening snack?

That's something that I can easily test (well, not so easily as I can't always rely on my little boy waking us up and I'd get hit if I set an alarm). The Nairns biscuit is 7g Carb so it's not negligible.

 

[Mark T]

Thanks HelenM, I think you might be on a winner here

Swapping my evening snack for cheese and a glass of red wine gave me a 5.6 before bed (that's repeatable too). My fasting this morning was 5.8!

Might need to retest without the glass of red wine as well 🙄

I did have the opportunity to do a 3am test this week, but I couldn't motivate myself to jump out of bed 😱

 

[Northerner]

...I did have the opportunity to do a 3am test this week, but I couldn't motivate myself to jump out of bed 😱

You need a small torch and a meter on your bedside table! I never get out of bed for a 3 am test - it would wake me up too much! 🙂