Basal testing/ Fasting?

Hello everyone,
I hope all of you are doing great and having a great summer (and if u r taking a summer course/job or a working adult and do not have an actual summer break just have a great day!)

It is the 4th day of Ramadan and it has never been this hard! I’ve already had to break my fasting on the second day (I may have jinxed myself for having a smooth great first day)
So far I’ve had to wake up every two hours or so to check on my BG levels. sigh I’ve had to disconnect my pump, reduced basal and even turned it off… all while fasting during the day!
I haven’t been sleeping enough and its all because of this. What’s driving me crazy is the fact that I’m having highs that reach 300 during the night and I just hate it! I seriously considered taking out my cgm and not test and just ignore the whole thing… but I can’t!
I haven’t been always this careful person who wants to maintain a healthy lifestyle and good BG numbers and I do like it! It makes me feel good and healthy and not always dizzy or nauseated.

I’ve read a few of the other posts on basal testing through fasting and it does seem that most of those who did fast for 4 hours or for a few meals and maybe they have fasted for more but I’m not sure. I’m fasting for Ramadan from the sunrise to the sunset and thats from 4:15am till 7:05pm (I would say about 15 hours) Anyways, this isn’t my first time trying to fast (I’ve been diabetic for 7 years now and I was able to fast the past few years with the rare occasional need to break my fasting) However, this is my first time fasting with a pump hence, my need to tune my basal.

I’m on Apidra and here are my basal rates:
12:00A 0.550
3:00A 0.450
6:30P 0.550
Total of 11.26U

I’ve been exercising for 30-40 min/jogging (honestly the weather does not help to do more, and I actually don’t know how I was able to finish those minutes I actually felt sick a couple of times)
The reason I would exercise is because my BG would be around 300 (dont worry I would check for ketones) and i would reduce my basal for two hours by 50% and at first it wouldn’t drop or anything but by the 30th min of exercise I would be dropping to fast that I have to turn off my basal; I would reach 50 and 48.
I really need to know any guidelines to follow or anything that would help me just have a stable not very low or very high BG! The first few hours after I start fasting (around 6-7am) I would start to go low so I turn it off (tried reducing it by 90%) and it didn’t work. However, around 12 or 1pm it would reach 290 and I would try to turn it back on and reduce it. It is a lot of work and I just want to find a fixed basal rate to help me out.

Any advice or tip is greatly appreciate it.

Sorry for the long post, I do have to run though as we r heading to Makkah for Ommrah.
Take care.


I just have a few comments but I don’t have the full solution. My general experience with fasting is that I’ve usually been rewarded with steady blood glucose numbers. But there are many moving parts to this puzzle so you’ll need to be patient and persistent.

The first thing I would recommend is keeping a 24-hour blood glucose chart that shows your basal rate profile across the bottom as well as any bolus insulin and time. You can also add meal times and descriptions. You don’t need to do this forever but when you’re struggling it helps bring some order to the seeming chaos. I would increase the number of fingersticks you do so that you have enough data to for analysis and changes.

Remember that you’ll need to change any basal rate two hours before it will have its intended effect. For instance, if you detect a pattern of going low at 2:00 a.m., then you’ll need to reduce your basal rate at midnight.

Whenever you go low, say below 70 mg/dl, for an extended time (greater than 20 minutes), you can expect a counter-regulatory jump in your BG. So, if a low happens when you’re fasting then it’s reasonable to conclude that you need to reduce your basal rate two hours before that low.

If your highs are not attributable to a reactive bounce from a low, then you could increase your basal rate two hours before you start to see that climb. (A CGM trace would make things easier, here but sufficient fingersticks can make this work.)

I am not familiar with all the aspects of Ramadan but I understand that when the sun sets, a social celebratory meal is consumed. Are you eating more than usual for this meal? This may be the source of your overnight 300’s. Perhaps you could go out for a 45 minute walk after the evening meal. Exercise post-prandially, especially 1-2 hours post-bolus is a great way to knock down trending highs.

As far as basal rates go, I always adjust in full tenth increments – in other words 0.4, 0.5, 0.6, not 0.55. There’s nothing magic about it but I find that for me, adjusting up from 0.4 to 0.5 is enough of an increment to make a difference. Adjusting in 0.05 or even 0.025 steps is much too slow and will try the patience of a saint!

In summary, keep a daily chart with basal and bolus insulin, fingerstick numbers, meals consumed, and exercise will help you to see some cause and effect relationships that you would not otherwise see just winging it. Make basal changes two hours before any desired BG change.

I think fasting is a great discipline. there must be something good about it since most of all the world’s great religions do it.

Good luck and be well!

Hi Anna,

I’m sorry you’ve been having such a hard time this year with Ramadan. Terry gave some good advice but I’d like to offer a slightly different perspective. You said that you did OK in the past when you were on MDI. Perhaps you could mimic that experience with your pump. If you cut your basal by 50% during Ramadan in the past, just cut your current basal by 50% and stop trying to fine tune every few hours. You’re probably constantly running a couple of hours behind the curve; at least your “stopped clock” might be right a couple times a day.

A couple of other thoughts - I assume you don’t drink water during your fast. If that is the case, dehydration may be giving you problems. Also you might consider eating normally for the rest of the day once you have a major high or low. If you try to eat just enough to keep yourself safe, you may not be able to get yourself stable and problems may just pile up making it hard to fast the next day.

I wish you luck with your fast. I’m sure that it’s not only a spiritual practice but also a way to be part of your community and not taking part even for a single day must feel like a loss.

Be well,


1 Like