How to Calculate Active Insulin On Board (IOB)

Does your blood sugar appear unpredictable at instances? When you stay with insulin-dependent diabetes, it most certainly does, and generally it may be arduous to find out what’s happening.

That’s why it’s essential to discover ways to calculate your insulin on board (IOB) as a result of should you’re not taking note of your IOB, your blood sugars will proceed to look random and unpredictable

Whereas taking note of your IOB won’t remedy all your each day blood sugar woes, it may enable you to out immensely. It’s a key element to raised diabetes administration and one thing that’s not introduced up usually or taught sufficient when you’re recognized.

Realizing your IOB might help you efficiently decide issues like if it’s protected to go for a stroll with out your blood sugar going low, or should you ought to inject extra insulin to right a excessive blood sugar, or should you 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 could have in your physique. I’ve additionally seen it described as BOB (Bolus On Board), or unused insulin.

Fast-acting insulin is the kind of insulin individuals residing with insulin-dependent diabetes use once we eat or have to right highs. Frequent 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 essential since injected rapid-acting insulin can final within the physique for 3-5 hours. That signifies that you have to be paying consideration not simply to what number of items 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 variety (3-5 hours) as a result of all of us metabolize insulin at a barely completely different price. Most insulin pumps shall be set to three hours, and most docs advocate testing one’s blood sugar about 2 hours after a meal bolus, partly to test IOB and if a ample meal bolus was administered.  

When you use an insulin pump, the pump will let you know your IOB from all boluses.

Nonetheless, it’s value noting that it doesn’t embrace 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.

When you use insulin pens, there are a couple of apps out there that will help you calculate and hold monitor 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

When you don’t have entry to any units or apps that calculate your IOB for you, or if you wish to know your “pump basal IOB”, you possibly can calculate your IOB pretty simply by yourself.

On this video, I’ll stroll you thru examples of tips on how to 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 impression your blood sugar in several conditions.

Listed below are two further 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 is usually a essential element 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 recognized with diabetes is that stacking insulin is dangerous. 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 should you didn’t get sufficient insulin through the first dose, must you simply wait 3-5 hours whereas your blood sugars are excessive earlier than correcting? Your IOB might help decide that.

If you calculate your insulin dose the IOB ought to be a element of the calculation. The calculation is that this:

Insulin for the carbs you eat +/- Correction to 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 is able to 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 certainly had gone low.

One other essential issue is decreasing the danger of low blood sugars. The one motive why we go low is that if we’ve got 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 understanding if it’s acceptable for what we’re about to do or if we’d like a small carbohydrate snack first.

When is it essential to concentrate to IOB?

Whereas you will need to concentrate on IOB all through the day,  these are three of crucial instances to pay particular consideration to it:

If you train

Your insulin sensitivity is heightened throughout and after train, growing the danger 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 be capable of modify 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 possibly can’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 great evening’s sleep might be arduous with diabetes and nobody desires to take care of 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 might help you assess if it’s protected to go to mattress, should you want a snack to stop a low blood sugar, or should you ought to take a correction dose for a excessive blood sugar.

Earlier than meals or corrections

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

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