• Guest - w'd love to know what you think about the forum! Take the 2026 Survey »

Basal Testing

db89

Well-Known Member
Messages
1,134
Location
Cumbria
Type of diabetes
Type 1
Treatment type
Insulin
I've seen this mentioned a couple of times and I've read a few links regarding it. As I'm not yet confident with adjusting my carb ratio I thought it might be worth giving this a go to check that I'm on the right dose as when I've seen it mentioned it's been recommended before changing anything to do with bolus. Just a couple of questions, sorry if they're daft!

Does it matter when I take my basal? I was planning on doing this over a couple of nights (18:00-00:00) as this would be the easiest time period for me to begin with - I normally take my basal around 19:00 every day. Depending on results I'll move on to different times.

Depending on where you read it says last meal and bolus should be 4 hours ago or 5 hours ago. Which is right so that I can time my last meal correctly?
 
Hi @db89, no question is a daft question.

The idea is that you start to basal test once the bolus insulin from your previous meal is used up. This is why 4 or 5 hours is stated. For most people, bolus insulin takes between 4 and 5 hours to be consumed, so you should be good if you leave 5 hours after eating before you start the test. In this case it would be that you ate lunch then didn't eat anything containing carbs or protein after that.

You should take your basal at your normal time while undertaking the test.
 
What basal insulin do you take?

It shouldn't matter what time you take your basal insulin, providing that you are (and have been) taking it at the same time, every day.

The only issue you may have (if you're anything like me and a lot of us on Levemir) is that the basal insulin doesn't work for the whole 24 hours. Because of this, your basal rate test results for the periods anywhere between 16-24 hours may be slightly inaccurate, not because you're needing more basal insulin, but because the coverage just isn't there. If you fit this criteria then a split dose may be for you.

I hope that makes some sense, maybe another forum member with better English skills that me can clear it up if it doesn't make sense

The majority of bolus insulins have a duration of action somewhere between 3-5 hours. You'll probably be alright with 4 hours as it's right in the middle of the range anyway. For me, I have very little bolus insulin on board after 3 hours.
 
Thanks for those answers @tim2000s, I'll give it a go over the next few evenings.

I take Lantus once daily @GrantGam and I take it at the same time each day (as close as possible). I've not adjusted my dose in about 3 months.
 
GrantGam said:
For me, I have very little bolus insulin on board after 3 hours.
Click to expand...
One of the things that's been quite revealing about using the various loop systems is that DIA tends towards a lot longer than we tend to give it credit for. It's quite surprising how much insulin is really left when we when you compare what happens running from a human/emotional perspective, rather than when things are being run unemotionally and systematically by an algorithm.
 
Once again thanks for the answers yesterday. I gave it a go last night and got an interesting result which I'm going to ask my DSN about when I get chance before I try again (that and I'm waiting for another refill of my test strips prescription).
 
Apologies for bringing this back up but I don't know what is going on! I haven't been able to reach my DSN yet but have reattempted this again a couple of times after lowering my basal after the first time. Every single time not eating sends me low within a few hours and I have to abandon it.

In late afternoon/evening I am seeing a pattern of my levels freefalling. Today is a good example; I had a snack mid afternoon which I think I underestimated the carbs in so I ended up at 12.0 nearly 2 hours after. A few hours later and I'm at 5.8.. had I corrected I would have had a hypo. What's confusing is I take my basal dose shortly before my evening meal so it should be about worn off and out of my system? Should I be putting this down to honeymoon and not try this for now?
 
You might want to minimize your concern with your 2 hour postprandial BS numbers and pay more attention to the "fasting" ones. You don't want to bolus/correct a 2 hr PP BS with more bolus. Like you noted you were 5.8 which is good. Maybe I'm old school here, but I don't think that I have EVER measured a 2 hour post prandial blood sugar on myself. And I contracted diabetes about the time that glucometers hit the market and test a lot. And I've done basal/bolus the entire time too.
 
Sorry I should make that more clear @TheBigNewt - I was 5.8 nearly 4 hours later before my evening meal. I only tested around 2 hours (when it had spiked to 12.0) as I needed to drive. I didn't take a correction dose.
 
yea
db89 said:
Sorry I should make that more clear @TheBigNewt - I was 5.8 nearly 4 hours later before my evening meal. I only tested around 2 hours (when it had spiked to 12.0) as I needed to drive. I didn't take a correction dose.
Click to expand...
Yeah I get that you didn't try and correct. So you probably took about the right amount of bolus for whatever you ate if you were at 5.8 basically fasting, bolus mostly over with. That would be a BS of about 100mg/dl for me which is great.
 
TheBigNewt said:
yea
Yeah I get that you didn't try and correct. So you probably took about the right amount of bolus for whatever you ate if you were at 5.8 basically fasting, bolus mostly over with. That would be a BS of about 100mg/dl for me which is great.
Click to expand...
I'm fairly sure that I didn't though I took a quick guess and I think when I've added up later that I took only half of what I should have for bolus which makes sense with such a spike I think.

However, I feel it fits a pattern of my levels dropping late afternoon and into the evening until I either abandon or hypo (when really the insulin should be out of my system). Last time I tried on Monday I started off at 6.8 before lunch at 13:15, had 73g carbs with bolus 15 minutes before. By 17:04 I was at 6.0 (so far so good) roughly 4 hours after - drove home and started testing. 18:21 I was at 5.3 and by 19:21 just before I would normally have my basal and eat my evening meal it was at 4.2 so I gave up and had my dinner or I would have gone hypo (I knew what was coming as my hands were already shaking).

I just don't seem to stop dropping in the evening even when my last bolus should be out of my system and my basal should be about worn off and need taking for the next 24 hours.
 
Yeah one would hope the bolus was about gone after 6 hrs, assuming it's either Humulog or Novolog not Humulin or regular. The endo might wanna reduce the basal a tad if that's the case. You didn't say how much you take. A 4.2 isn't horrible, that's a BS of 75mg/dl here. And you are new at this, so it's entirely possible that you still make some of your own insulin too. As in basal insulin. What you're gonna find is that you won't feel low with a BS of 4.2 forever. I had a 3.0 (54) yesterday and felt 100% fine. I'm not saying anyone should get to those levels often but any long time Type 1 will tell you that you tolerate hypoglycemia much better with time.
 

I'm on Lantus for basal (currently 6u) and Novorapid for bolus (1:15 most of the day and 1:20 in the evening). I already reduced my basal by 2u the first time I tried this test after discussing with my DSN.

My target range is 5-8mmol. I'm pleased I recognised the beginnings of a hypo at 4.2 - hypo unawareness in the UK means surrendering my driving licence which is something I can't tolerate.
 
6 units of Lantus a day is very little basal. I'm assuming it's the same units as we use. I take a low dose and I take 25 units. So you must still make some intrinsic insulin is my guess. And you've only "had it" for a couple of months so that's likely. And that's terrible about surrendering your drivers license. Heck I passed out at an intersection many years ago, I think paramedics had to revive me with D50, and nobody reported anything lol. I may have driven myself home!
 
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.…