Consistent low glucose during sleep

[danielmg]

Hi @danielmg, as @Ljc says, I haven't used basal insulin for 8 years now - I stopped needing it 4 years after diagnosis. What levels are you dropping to overnight? The non-diabetic level is actually lower than the one we are told to regard as 'hypo' when we are using insulin - it can drop as low as 3.3 and not be considered hypo in a non-diabetic person. So, if you do not have any active insulin (apart from that being naturally produced by your body) then anything above 3.3 is normal. Unfortunately, the Libre won't let you set your range below 3.9, so that can lead to a lot of phantom overnight 'hypos' being registered. They are not dangerous, as they would be if you still had basal insulin onboard, but it does mess up your Libre stats! 😱 There's no harm in having a jelly baby to raise levels a little if it makes you feel more comfortable, that's generally what I do if I wake in the night a bit low 🙂 Note also that your levels naturally drop to their lowest levels in the middle of the night, when your liver is least active.

I had a C-peptide test a couple of years ago which showed that my pancreas is producing a 'reasonable' amount of its own insulin, which is why I don't need the basal. The consultant couldn't provide an explanation other than the fact that diabetes is a very wide spectrum and can vary considerably in individuals. I still need bolus insulin with my meals, about 20 units a day currently. Of course, the other investigations that are taking place for you may reveal a different cause, so hopefully they can pinpoint things for you 🙂

Let me know if you have any questions! 🙂

Thank you @Northerner for the very helpful reply, I appreciate it.
I've attached an image of my latest average libre readings from the last 2 weeks (easier to see this way).

The readings tend to sit just below 3.9 for the majority of the time, and occasionally slightly lower/higher, but very small deviation from the mean results. It is good to know however that this could be normal. Most of the time i 'feel' ok, however I do suffer quite badly with hypo unawareness, and this could be a contributing factor to not waking up so much during the night. It does sound like I am in quite a similar position to yourself, and even though I hope this is nothing to worry about, it will be re-assuring to have some further tests just to check in more detail.

Thank you everyone for your help so far. This forum is incredibly supportive, and I wish we could have a meet up event in the future once the COVID-19 situation is hopefully under control.

 

[Inka]

I'll normally have either a wholefood bar (made of dates, nuts) or a piece of fruit (apple, pear, banana). The other minor annoyance I have is that most nights I wear a retainer after brushing my teeth. Therefore I've just bought some small apple juice cartons I could alternatively drink instead of the aforementioned foods.

Most evenings I'll eat my evening meal at approx. 6-7, and likely have another snack at about 10 before bed. My average bolus range is between 2-4u per meal at the moment, so not a lot (even though my carbohydrate intake for this meal would normally be between 60-80g).

Ok, well you could try different snacks before bed to see if something else works better. All the ones you’ve mentioned tend to be absorbed quite quickly and don’t last long, particularly the apple juice, dried fruit and fruit.

I’d try a Weetabix and full fat milk or, a digestive biscuit or two plus some cheese, or 3 or 4 oatcakes with peanut butter. See if those help at all.

I always try to eat my evening meal no later than 6pm because otherwise I find the bolus can drag on and be active at bedtime.

 

[rebrascora]

@Northerner
Alan many thanks for that really helpful information. It is to a certain extent what I suspected, in that non diabetics may well drop below 4 but surprised that they can go as low as 3.3. It certainly makes me feel more comfortable with the low levels I am experiencing during the later part of the night at the moment when my levels are dropping just below the red line with no evening basal on board, but I am currently needing the normal amount through the day. Do you remember if your basal needs slowly dwindled both day and night or if you saw a change during one period and then the other. Would love to hope that I could, at some point, do away with my basal too and become another "oddball diabetic".

@danielmg
What makes you think that you don't have hypo awareness?
I wonder if you have an unreasonable expectation of it?
As Alan says, many non diabetic people drop below 4 during the night and don't detect it and it doesn't make them wake up. Obviously if you drop lower than that then you would expect to be disturbed so if you are not waking up when your levels drop lower than that then that is not good, but through the night it is more difficult to detect lows because any changes are very gradual and your body is not physically active so it is not drawing glucose from your blood like it does through the day which means change in levels is even less perceptible.
Obviously if you are going so low that you are needing the assistance of someone else to come back up, that is another matter, or if you are dropping below low 3s during the day and not feeling anything then that would be concerning, but I do wonder if some people assume you have lost hypo awareness because you don't notice until you drop below 4, which is an unreasonable expectation.
The definition of a hypo is also slightly murky because DAFNE considers it 3.5 rather than 4 which I think is probably more realistic as it then gives you that 3.5-4 range to detect it.... if that makes sense

 

[danielmg]

Ok, well you could try different snacks before bed to see if something else works better. All the ones you’ve mentioned tend to be absorbed quite quickly and don’t last long, particularly the apple juice, dried fruit and fruit.

I’d try a Weetabix and full fat milk or, a digestive biscuit or two plus some cheese, or 3 or 4 oatcakes with peanut butter. See if those help at all.

I always try to eat my evening meal no later than 6pm because otherwise I find the bolus can drag on and be active at bedtime.

Yes that's a good idea, thank you @Inka. I try to find a balance between fast and slow-acting carbohydrates with a correction. I do have a wholefood bar type with oats and lower GI ingredients included. I do like weetabix/porridge so maybe 1 biscuit/sachet before bed would be useful to see if this has any difference on overnight readings. Partial to oatcakes as well, so plenty food for thought (no pun intended).

 

[danielmg]

@danielmg
What makes you think that you don't have hypo awareness?
I wonder if you have an unreasonable expectation of it?
As Alan says, many non diabetic people drop below 4 during the night and don't detect it and it doesn't make them wake up. Obviously if you drop lower than that then you would expect to be disturbed so if you are not waking up when your levels drop lower than that then that is not good, but through the night it is more difficult to detect lows because any changes are very gradual and your body is not physically active so it is not drawing glucose from your blood like it does through the day which means change in levels is even less perceptible.
Obviously if you are going so low that you are needing the assistance of someone else to come back up, that is another matter, or if you are dropping below low 3s during the day and not feeling anything then that would be concerning, but I do wonder if some people assume you have lost hypo awareness because you don't notice until you drop below 4, which is an unreasonable expectation.
The definition of a hypo is also slightly murky because DAFNE considers it 3.5 rather than 4 which I think is probably more realistic as it then gives you that 3.5-4 range to detect it.... if that makes sense

I've just felt i tend to struggle in certain situations, particularly at work, with not fully recognising that my glucose is low. There's examples when I've left work with a BG of ~6-8, and then travelled home just over an hr later to find a BG of ~2.5-3 and not had many symptoms in the time between. On the other hand, I used to get 'hypo' symptoms when I wasn't low (~5.0) - I realise this is just anecdotal and could be due to a variety of reasons. I would say however I have improved a little since starting to use the libre, but also haven't been back to work since using, so this will be interested to see the trend lines throughout the day.

Yes I would agree that the hypo definition can differ, with 3.9 and below always being the reading I have used to determine this. On the note of DAFNE, I have been placed on a waiting list to start this course soon.

 

[Alfie Foster]

I had the same problem, thank you for the helpful information!

 

[danielmg]

Good to hear this has been a helpful thread @Alfie Foster.

Just a quick update on last night's readings - I had 25g of seeded oatcakes before bed; glucose only went up to ~6.5, then returned to below 3.9 all night until I woke up again.

 

[trophywench]

Mmmmm - I honestly think you probably need to try carbs, protein and fat as your late night snack. A good many years ago a T2 chap said he always found 2 of the 'mini' Nairn's Oatcakes (ie 5g carb each) buttered with a bit of 'hard' cheese atop each one, consumed as he locked up and climbed the stairs to bed, sorted his BG out all night. He'd tried em plain, he'd tried em plain with cheese, but when he added the butter too, Bingo! Hence I'd suggest you do a clinical trial of that combination and see if it makes any difference but always bearing in mind that under about 4.5 the Libre trace will inevitably read lower than 99% of people's actual BG.

 

[pm133]

My theory is that my muscles are sucking the glucose out of my blood to replenish their stores whilst I am sleeping and perhaps my liver is also clawing some back. It is definitely connected to the muscle burn exercise during the previous day(s) for me. If I don't exercise I need evening basal insulin. If I do light exercise like a brisk walk, it doesn't have such a dramatic effect.

I'm not sure if muscle cells need insulin to get that glucose. I suspect they do. In which case this could well just be your liver dumping glucose during the day and then retrieving it at night.

As you eat very few carbs, I wonder if your body is then having no option but to go through those "boom and bust" cycles which presumably are much harder to control.

I am not sure, just guessing really.

 

[rebrascora]

Well I was 8.2 at bedtime, so I had some cheese and 2 thirds of a stem ginger cookie (approx 6g carbs). Waited until my levels went above 10 and went to bed, slept like a log but my levels slowly and steadily decreased in a lovely straight line graph to 3.9 when I woke up at 6.18am feeling hot and uncomfortable.
in view of our discussions on this thread, I decided not to treat it and see what happened because I only had the very tail end of my morning Levemir on board. Went back to sleep but I continued to drop and decided to get up when it hit 3.3 and see if Foot on the Floor syndrome would kick in and fix it rather than take carbs and then have to inject insulin to cover FOTF. I waited well over half an hour and only managed to get to 3.6 and my heart was pounding so I had 10g carbs. Levels started increasing almost immediately and topped out at 11.6 but then started to come down a little. Did some exercise at mid day thinking it would help but went up to 14. I have been physically active all afternoon shifting horse manure and I am down to 9 having resisted the urge to correct as per DAFNE guidance after a hypo.
Tonight's experiment will be to go back to eating late which was my norm. if that doesn't work then I will go out and get some oatcakes and try the butter and cheese routine with those.

 

[rebrascora]

The lows during the night have only started happening since I upped my resistance exercise during the day. Prior to that I didn't have a problem with night time hypos and I was taking as much as 7 units of Levemir at night at this time last year and the same 16 units during the day. Now I am down to none at night and still dropping too low.
Since we know that exercise does reduce your BG levels without having to inject extra insulin to help your muscles gain access to it, it seems fair to assume they are able to suck glucose through the cell walls when they need it rather than insulin pushing glucose when there is too much. I imagine it a bit like osmosis. When the glucose levels in the cells of the muscles drops lower than the blood stream, because the muscles are burning or have burnt it, the glucose migrates into the cells because there is a lower concentration, but if the glucose in the blood stream is higher than in the cells and the cells don't need it, it needs insulin to push it through and make them store it. I don't know if that is correct but my scientific based mind has come up with that theory.

 

[nonethewiser]

Went back to sleep but I continued to drop and decided to get up when it hit 3.3 and see if Foot on the Floor syndrome would kick in and fix it rather than take carbs and then have to inject insulin to cover FOTF. I waited well over half an hour and only managed to get to 3.6 and my heart was pounding so I had 10g carbs. Levels started increasing almost immediately and topped out at 11.6 but then started to come down a little.

Liver dump to get you out of hypo, see effects hours after if untreated, happens with myself. Better off eating something sweet to stop it happening, also to keep awareness in place long term.

 

[Inka]

I waited well over half an hour and only managed to get to 3.6 and my heart was pounding so I had 10g carbs. Levels started increasing almost immediately and topped out at 11.6 but then started to come down a little. Did some exercise at mid day thinking it would help but went up to 14.

Did you eat breakfast? I presumed you didn’t? I find that mornings are the one time that I need to eat even when high (I usually wait till under 7 or 8). If I wait, my blood sugar will stay stubbornly high even with two corrections or more. However, correcting and bolusing and eating will shift it and then my blood sugar will drop normally.

 

[rebrascora]

@Inka
I ate my protein bar (10g carbs) for breakfast about 45 mins after I got up, which is standard timing for my breakfast but I had a glass of water a cup of coffee with cream and a chunk of cheese in the interim period, which is typical of my morning routine.
@nonethewiser
I agree it was liver dump and I have learned the lesson. I firstly wasn't convinced that it was a true hypo as per discussions above that non diabetics can drop that low (the DSN also queried whether I was in fact having real hypos when I consulted her about the problem...with Libre reading slightly lower than finger prick at low levels) and also that I had no real active insulin on board at the time. I also fully expected Foot on the Floor to kick in as it usually does the moment I get out of bed and by the time I realised that is was a proper hypo and my heart was pounding and the adrenaline was kicking in, I didn't want to have jelly babies and then inject insulin and have to eat more carbs after that, so I just ate my breakfast bar which kicked in pretty quickly anyway (I double checked by finger prick). By then though the adrenaline had triggered the liver dump and foot on the floor was probably kicking in too. I just don't understand why my levels drop so significantly through the night with just the tail end of my morning Levemir
I would point out that this was an experiment this morning and not how I would normally deal with a hypo or have been dealing with them in recent days.
My problem tonight is going to be that even if I don't inject any Levemir, same as last night, my liver is going to claw back at some point which means I may be doubly likely to hypo again tonight. May have to set alarms and have plenty of carbs to hand on the bedside table.
Eventually gave in and injected 4 units of Fiasp at 4.45pm when my levels were back up to 11.4. Have had some soup and things are settled in the 6s at the moment. Going to eat a late low carb evening meal with no bolus and go to bed on at least 10 again and set an alarm for 4am.... jelly babies at the ready.

 

[danielmg]

Quick update: Got my SST results from my diabetes clinic last week. I passed the testing, so no abnormalities as far as my cortisol levels are concerned. I am still getting low glucose during sleep, but I believe I'll be scheduled for a follow-up appt. in Jan/Feb to check my progress on this.

 

[everydayupsanddowns]

Thanks for the update @danielmg

Hope they get the bottom of it, with no basal insulin, and if you are taking your last bolus around 6pm then it sounds like your low BG is not insulin related (and may be partly connected to Libre’s tendency to read lower at low levels, and higher at high levels?)

 

[danielmg]

Thanks for the update @danielmg

Hope they get the bottom of it, with no basal insulin, and if you are taking your last bolus around 6pm then it sounds like your low BG is not insulin related (and may be partly connected to Libre’s tendency to read lower at low levels, and higher at high levels?)

Thank you @everydayupsanddowns
I've tried to test both BG and Libre if I wake up randomly through the night, however I don't have much data to go off so far. 1 BG reading was higher and 1 lower than Libre, so a bit inconclusive. The so-called 'Foot on the Floor' syndrome doesn't help with this either, as normally when I wake up (even randomly through the night), there tends to be a small increase. Difficult to get an accurate comparison without something like a CGM for blood as well as interstitial fluid. Either that or someone (a vampire) testing my blood while I sleep (not preferred option).