• Guest - w'd love to know what you think about the forum! Take the 2025 Survey »

Basal testing

thewestiesmum

Well-Known Member
Messages
143
Location
North Yorkshire
Type of diabetes
Type 1
Treatment type
Insulin
I'm aware that basal testing can be done either over a 24 hour period or over a few days.
How do you fit your basal testing in to fit in with your day to day life and meals mainly teas/evening meal?
I never know when to fit a basal test in. I wake around 7am because I have to do my basal insulin. I usually get up around 9am for breakfast. I go out to work from 11am - 1pm. Afternoon is usually free to do whatever I like. I have tea around 6:30 - 8pm ish......
If anyone could help me out on this I would be grateful.
One thing which does worry me is that either my bg wouldn't be in my target range when I want to start a test or I would never be able to complete a basal test because I would end up hypo every time.
 
Hi. If you can afford it, having Freestyle Libre 2 would help a lot as the daily graph shows the BS trend and you can tell to a large extent whether the Basal is too high or low. It also helps adjust the basal as needed each day particularly if you split your Basal
 
It's actually not recommended that you do a Basal Test over 24 hours actually. I know some people do that, but there's a risk that doing it for 24 hour would provoke responses from your body that are only there because of the extreme length of the Basal Test itself.
 
@thewestiesmum I am aware you have struggles and issues so would tread carefully re the basal tesing as I am not 100% sure they provide the full answer for everyone, as my requirement in the monring, lunch and dinner are completly different so think a 24 hour basal test or even the 6 hour slots can cause more confusion re the result and then what to do with it.

I understand where @StewM is coming from re '24 hour would (I think better to say could) proke responses from your body' but no-one has advised how your body would respond - Yes I have done 2 full days yes I got a strange result but probably not what would be expected (had lowing levels rather than rising or steady flat levels after lunch) but assume this may be the reason why you are not recommended to do a full 24 hrs.
 
It depends what insulin you are on, timings and if it requires a split dose. I'm on a split dose of Levemir so I need to skip lunch (or eat low carb) to see if my morning dose was correct. Later in the week, I can also skip dinner (or eat low carb) to see if my night dose is correct.
 
Last edited:
You may find basal requirements vary with time of day. I find basal requirement falls a bit after around 1.5 to 2 days of not eating.
If your basal is about right you should be fairly stable and rise or fall rate should be small.

I'd suggest since you are still having issues with hypos you start in the morning and run as long as you are comfortable with to help get closer to your basal requirements. Break your fast in time for adjustments which may be necessary after your meal before you go to bed. The CGM should help with trends but suggest you also do finger prick tests during the test period as well. Treat any hypos and just do the test on another day.
 
Hi, you wouldn't need to fast you would just need to eat extremely low carb or no carb throughout the day. With a bit of planning of what to eat it can be done. Best of luck
 
Soplewis12 said:
Hi, you wouldn't need to fast you would just need to eat extremely low carb or no carb throughout the day. With a bit of planning of what to eat it can be done. Best of luck
Click to expand...

@Soplewis12 the reason why fasting is done is that you don't get any distortion with protein you may eat. Even for T1 that eat low carb still inject (but a lot less) for the protein eaten. Also on the DAFNE course told not to count carbs in veg (I didn't agree with this comment) but later on said if you have a high veg meal you do need to count the veg As always nothing is straight forward!
 
Hi, this might not work for you but this is how I run the test...

- I was told I needed to run the test over multiple days otherwise your body will start to release extra glucose;
- If you have a hyper or hypo then you need to stop the test, that's ok because it has shown your basal rate is off so tweak your rates and test again on another day;
- You need to run the test when you are in range and have no IOB nor food releasing glucose so you need to start the test 4 hours after your last bolus and meal + ensure your last meal wasn't too high in fat nor protein.
- Finally avoid testing when you are running about / doing exercise etc.

I then test in four time slots:

Morning - 6am to 12pm (i.e. no breakfast, no food nor insulin from 2am)
Afternoon - 12pm to 5pm (i.e. no lunch, no food/insulin from 8am)
Evening - 4pm to 10pm (i.e. early lunch, late dinner, no food/ insulin from noon)
Overnight - 10pm to 6am (i.e. early dinner, no food/ insulin from 6pm)

You need to test your BG every hour (easier with a Libre/ CGM).

If your basal is at the right level, in theory your BG shouldn't fluctuate by more than 1.6 mmol/L.

I think work on the following rule of thumb:
If BG values rise more than 1.6 mmol/l: increase your basal rate by 10-20%
If BG sink more than 1.6 mmol/l: lower your basal rate by 10-20%

However, unless you are on a pump you might not be able to find the right level for the whole day. I suffer dawn phenomenon and could never find a dose (even my moving the timing of my basal insulin) that corrected for that without also pushing me into Hypos in the afternoon.

Hope that helps a bit. Good luck
 
rosemaree said:
@derivadow thanks so much for sharing this! Can I ask how you managed to work around your dawn phenomenon? My Dr told me to keep upping my basal until my morning levels were right, but I just end up with lows during the day and still have a high fbg
Click to expand...

I’ve ended up going onto a pump (so that I can increase insulin from 3am).

While I was on MDI I couldn’t find a way of sensibly controlling it, just increasing basal resulted in hypos every afternoon/ skipping along with jelly babies! So I woke up every night to give myself a bolus.

Things that helped a bit:
- eating earlier in the evening
- main meal at lunchtime and smaller evening meal
- low fat and protein evening meal.
- adjusted when I injected basal insulin to minimise the afternoon basal bulge (I injected 7:30am and 8:30pm)

But ultimately it wasn’t really sustainable.

Sorry I don’t have a better answer.
 
I did similar to improve things. The other thing that worked for me was delaying breakfast for a bit after waking, as I always found the hour after waking to be the worst (in terms of needing lots of insulin).
 
Soplewis12 said:
Hi, you wouldn't need to fast you would just need to eat extremely low carb or no carb throughout the day.
Click to expand...
Sorry this does not match my experience or other advice on basal tests I have encountered. Eating anything affects my blood glucose (at least down to very low carb), and drinking coffee even with double cream also affects my blood glucose levels.
So my suggestion would be check blood glucose in range, no rapid acting insulin within the last 4 hours, water only fast (you can add salt to the water if needed), check for rise or fall in blood glucose. Try to avoid other things which you are aware affect your blood glucose over that time period e.g. exercise. Break the fast in time for any adjustments before going to sleep - probably more important for OP as they are struggling with hypos.
As we know there are lots of things that can affect blood glucose and insulin impact upon it ... I prefer to eliminate the potential for food to contribute to this during a basal test.
 
rosemaree said:
@thewestiesmum, I don't have any answers for you, but this is one of the things I came online to read about. I am inclined to think I would also end up hypo before managing the tests though!

Hopefully some more informed people will be along soon!
Click to expand...

Your fear is the reason to basal test. If you need to “feed” your basal insulin to avoid going low, the basal rate isn’t right.
 
I am quoting what I was informed of from specialist diabetic nurse in March 22. Worked for me but not all hats fits all.
 
Soplewis12 said:
I am quoting what I was informed of from specialist diabetic nurse in March 22. Worked for me but not all hats fits all.
Click to expand...
Many of us find we need to inject for protein when we have a no carb meal, so I wouldn't do a basal test with food.
But yes, It may work for some.
rosemaree said:
Can I ask how you managed to work around your dawn phenomenon? My Dr told me to keep upping my basal until my morning levels were right, but I just end up with lows during the day and still have a high fbg
Click to expand...
Very difficult when not using a glucose sensor.
If it happens every day you could set an alarm for a few nights to try and find out at what time you start to rise, so you can take a correction. But that would be a lot of work, and having to wake up to test isn't all that fun either. And taking a correction when sleeping has its own risks of course.

I'm lucky in that I have a Libre with alarms, so it wakes me up when I start to rise and I can do a correction safely because it will wake me up if I go low as well.
rosemaree said:
I am inclined to think I would also end up hypo before managing the tests though!
Click to expand...
That is exactly the goal of the test; if you go hypo without eating, your basal is too high!
 

Hi @derivadow thank you for your reply and for explaining how you do your basal test in 4 time slots.
Please can you explain why each time slot is a different length of hours that you run the test for ie
Morning - 6am to 12pm - 6 hours
Afternoon - 12pm to 5pm - 5 hours
Evening - 4pm to 10pm - 6 hours
Overnight - 10pm to 6am - I presume this one is because it's overnight.
 

Hi @thewestiesmum, sorry for the delay in answering this. There's no medical reason really, I just find it more practical i.e.

- I wake up at 6am so haven't eaten overnight by noon I'm hungry but that's also that's the earliest I would want to eat lunch!
- Afternoon because I finish my breakfast at 8am (need to get the children ready for school, sort myself out etc. and I'm WFH) and noon is 4 hours after that, I could leave it run beyond 5pm but there's no point...
- 4-10pm because 4 hours afternoon an early lunch (noon) is 4pm then want to have enough time to eat before I go to bed
- 10pm-6pm yes because overnight. I could eat a bit later but that gets a bit tricky because I also need to feed the family and I don't want to cook twice!
 
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn More.…