How to Calculate Active Insulin On Board (IOB)

Does your blood sugar appear unpredictable at instances? In the event you stay with insulin-dependent diabetes, it most definitely does, and generally it may be exhausting to find out what’s occurring.

That’s why it’s vital to learn to calculate your insulin on board (IOB) as a result of for those who’re not taking note of your IOB, your blood sugars will proceed to look random and unpredictable

Whereas taking note of your IOB is not going to clear up your whole day by day blood sugar woes, it will probably provide help to out immensely. It’s a key part to raised diabetes administration and one thing that isn’t introduced up typically or taught sufficient when you find yourself identified.

Realizing your IOB can assist you efficiently decide issues like if it’s protected to go for a stroll with out your blood sugar going low, or for those who ought to inject extra insulin to right a excessive blood sugar, or for those who ought to eat a snack earlier than mattress so that you gained’t must get up in the course of the evening to deal with a low blood sugar.

What’s Insulin On Board

Insulin on board is how a lot lively rapid-acting insulin you’ve gotten in your physique. I’ve additionally seen it described as BOB (Bolus On Board), or unused insulin.

Speedy-acting insulin is the kind of insulin folks dwelling with insulin-dependent diabetes use after we eat or must right highs. Widespread model names of lively insulin are: Humalog, Novolog, and Fiasp. It’s additionally the kind of insulin that’s utilized in insulin pumps.

An excessive amount of IOB will result in low blood sugar (hypoglycemia) and too little to excessive blood sugars (hyperglycemia).

IOB is vital since injected rapid-acting insulin can final within the physique for 3-5 hours. That signifies that you ought to be paying consideration not simply to what number of models of insulin you inject but in addition to how a lot is left of that dose as much as 5 hours after your injection(s).

How lengthy insulin is lively within the physique is a spread (3-5 hours) as a result of all of us metabolize insulin at a barely completely different fee. Most insulin pumps shall be set to three hours, and most medical doctors advocate testing one’s blood sugar about 2 hours after a meal bolus, partially to examine IOB and if a enough meal bolus was administered.  

In the event you use an insulin pump, the pump will inform you your IOB from all boluses.

Nonetheless, it’s price noting that it doesn’t embody the basal (background insulin) which can be rapid-acting insulin. Overlooking the pump basal insulin when discussing lively insulin is problematic particularly for train, since an excessive amount of IOB, from boluses or pump basal, will make blood sugars drop.

In the event you use insulin pens, there are a couple of apps out there that will help you calculate and hold observe of your IOB comparable to RapidCalc (not FDA accredited) or MySugr (EU solely). There may be additionally a smartpen known as InPen out there within the U.S.

Find out how to calculate IOB

In the event you don’t have entry to any gadgets or apps that calculate your IOB for you, or if you wish to know your “pump basal IOB”, you may calculate your IOB pretty simply by yourself.

On this video, I’ll stroll you thru examples of how you can calculate your “pump basal IOB” and your IOB from injections.

I’d advocate going via the train of calculating your IOB a couple of instances and begin taking note of how completely different ranges of IOB affect your blood sugar in numerous conditions.

Listed here are two extra examples

Basal IOB (pump) Instance

Basal per hour is 1 IU, assuming insulin is lively for 4 hours within the physique:

1 IU x 25% + 1 IU x 50% + 1 IU x 75% + 1 IU x 100% = Whole: 2.5 IOB

Bolus IOB (MDI) Instance

1 IU injected 1 hour in the past and a pair of IU injected 3 hours in the past, assuming insulin is lively for 4 hours within the physique:

2 IU x 25% + 1 IU x 75% = 1.25 IOB

Why you must care about IOB

Realizing your IOB could be a crucial part to understanding in case you have an ample quantity of insulin on board for a given exercise. It’s the only greatest indicator of how your blood sugar will react throughout completely different instances and actions.

One of many first issues many individuals are taught after being identified with diabetes is that stacking insulin is unhealthy. Stacking insulin means taking a couple of dose of rapid-acting insulin inside the 3-5 hour timeframe whereas it’s lively within the physique.

However what for those who didn’t get sufficient insulin through the first dose, do you have to simply wait 3-5 hours whereas your blood sugars are excessive earlier than correcting? Your IOB can assist decide that.

Whenever you calculate your insulin dose the IOB needs to be a part of the calculation. The calculation is that this:

Insulin for the carbs you eat +/- Correction on your present blood sugar – IOB = Dose advice

So let’s say I’m not consuming, my blood sugar is 250 mg/dL, my goal blood sugar is 100 mg/dL, my correction issue is 50, and my IOB is 1 IU, this could be the calculation:

0 IU for carbs + 3 IU Correction dose ((250-100)/50)) – 1 IOB = 2 IU

Had I not taken IOB into consideration, I’d simply have injected the three IU and most definitely had gone low.

One other crucial issue is lowering the chance of low blood sugars. The one cause why we go low is that if we have now an excessive amount of insulin in our methods, an excessive amount of IOB. So taking note of our IOB wants for various actions is vital to figuring out if it’s applicable for what we’re about to do or if we’d like a small carbohydrate snack first.

When is it vital to concentrate to IOB?

Whereas it is very important give attention to IOB all through the day,  these are three of crucial instances to pay particular consideration to it:

Whenever you train

Your insulin sensitivity is heightened throughout and after train, growing the chance of low blood sugar. By taking note of your IOB, and the way your blood sugars react once you do several types of train, you’ll have the ability to alter your IOB (by adjusting your insulin within the hours earlier than you train) to be able to train with balanced blood sugars.

And in these conditions the place you may’t plan forward, you’ll know in case you have an excessive amount of IOB and also you’ll want a carbohydrate snack.

Earlier than mattress

Getting a very good evening’s sleep might be exhausting with diabetes and nobody needs to cope with low blood sugars at evening or waking up with a blood sugar hangover after having excessive blood sugars all evening.

Checking your IOB and blood sugars earlier than mattress can assist you assess if it’s protected to go to mattress, for those who want a snack to forestall a low blood sugar, or for those who ought to take a correction dose for a excessive blood sugar.

Earlier than meals or corrections

IOB needs to be a part of each meal and correction calculation and may make your insulin doses extra exact. 

Realizing your IOB permits you to dose when wanted, eat once you really feel prefer it, and it helps to construct confidence within the insulin doses you are taking.