Happy Saturday, and welcome back to our weekly advice column, Ask in D'Mine! hosted by old stager type 1, diabetes author and educator Wil Dubois.

Just last hebdomad, Wil looked at how long we PWDs (hoi polloi with diabetes) could by and large survive without insulin in our systems. Today, he explores how long a bolus dose of this BG-lowering elixir power last in your system once disposed. Hint: information technology's not cut-and-dry!

{Got your own questions? Email us at AskDMine@diabetesmine.com}

Amanda, type 1 from Oregon, writes: Wil, First of all, I love your advice and really appreciate everything you act up! I've had a Medtronic heart for around 4 years instantly and I give birth a interrogation about the active insulin time. I have mine set at 4 hours and my endocrinologist says that's pretty standard for most of his patients. However, sometimes I think this is too long. If I test and have a blood sugar of, tell 150 and it has been 3 hours since I gave myself insulin and ate, my pump says that I should take 0 units because I still have insulin connected display board.

Sometimes I'll go onward and give myself a unit to bring it down because I simply recollect my bloodline sugar is probably not going to come go through well in the incoming hour, and may actually go up. I actually have a CGM now, and then I can now see break when I have peaked after a meal, and whether I am coming down operating theatre going up still. My question is, is there a good way to work what your actual active insulin time should cost? I'm sure it varies from person to somebody. I retrieve I may need a shorter metre but I can't reckon of a good means to tryout this.

Wil@Ask D'Mine answers: Give thanks you! Actually, there are some good ways you can estimate prohibited your active insulin time, each variations of the very subject—but first a teeny-weeny scop. For those of you non in the have intercourse, active insulin time (also titled length of action) is a measure of how perennial insulin has the ability to bring dow blood glucose in your body. It matters for whatever insulin user, but especially for a pumper, because it's one of the metrics the pump uses to calculate how much insulin to give us under various circumstances.

Now, IT needs to be same upfront that all the frickin' pumps are different in how they track and deal with this active insulin—and all but atomic number 102 one properly understands how their own particular pump works in this regard. Some pumps track insulin carry out in a curvilinear way, others in a linear fashion. Both deduct the on the go insulin only from department of corrections. Others from meals and corrections. Allay others only depending on how more below butt you are. I don't bear time to move into the details on each pump today, positive it gives me a concern all fourth dimension I think of it, but I promise to spend a overall column on it… someday. Maybe in 2017.

Anyway, the current batch of Med-T pumps like yours let you set active insulin time anywhere between two and eight hours. Why? Is it because zero two persons with diabetes have the like existent insulin time? Spell that is honorable, I suspect the real reason out is that no two endocrinologists can agree on what the hyperactive insulin time should be.

Like your doc, I get hold that tetrad hours works great for most of my pumpers, but for what IT's worth, the leading endo in our state is insistent that active insulin should be set for 3 hours in all patients. This has led to a some-year-tall passive-aggressive "battle" betwixt USA. She re-sets all my pumpers' active insulin time every time she sees them, then I change it dorsum again the next sentence I run across them. Simply other notables, so much A CDE John Walsh of Pumping Insulin fame, go the opposite direction and reason active insulin time should be set at six hours. WTF???

And actually, your pump ships from the factory with its default active insulin time set to six hours, because, according to the pump's manual, this "near closely matches the published knowledge domain data."

Very? Published where, pray tell apar?

Maybe they were looking this famous chart:

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That one comes from a Novo Nordisk study. And while it shows that in a test tube, firm-acting insulin still has some ability to function after six hours, I'm not personally convinced that in your organic structure information technology really has enough punch left to have whatsoever realistic effect towards the end of its turn tail. That end couple of hours looks beautiful flat to my eye. But don't take my word for IT. Just read the small print. In the prescriber's info sheet for Novolog, IT states quite clearly that in an FDA approval study for that drug Novo found the duration of action of Novolog is tercet to five hours. That's a lot of variation in a pretty small sample size of 22 type 1 adults. Or in Novo-speak: the action of insulin "English hawthorn vary considerably in different individuals." Oh. But information technology gets eve better. Conjecture what? The famous duration of action graph? Information technology's the average information from those 22 folk.

Of course, to his citation, Walsh is quite correctly worried about the endangerment of insulin stacking causing lows in some brands of pumps, so he's erring unofficially of care. Still, wherefore rely connected published information about other people when it is within your big businessman to easy figure exterior your very own face-to-face activist insulin clock time?

Present's all you have to do: First, download your pump and CGM data. Following, fix yourself a double of your favorite drink that gets you in a relaxed mood. You are going to pass some considerable time with twine theory. Not to worry, this isn't particle physics! I'm talking about the little strings on the computer that show you the drunken wanderings of your blood sugars throughout the days and weeks before your download.

Instantly, I want you to pay specific attention to trace lines afterwards meals. In a perfect world (Ha!) your tracing line will curve smoothly upwards after a meal, softly crest, then return to its baseline in about four hours, departure behind a Vanessa Stephen curve that would make any statistician vain.

Preceptor't hold your breath for that.

If your correction factor or insulin-to-carb ratios are wrong, set a trifle weakly, or if you are off in your carb counting skills, you might not be acquiring enough insulin and you won't return to service line. But for our purposes, that won't matter. Pay attention to the chase after of the trace, before it reaches the next bolus or meal. Does it flatten out? Or is it still dropping? If information technology's still coasting downhill, IT's still doing its affair and a has non reached the end of its about time. If it's flattening KO'd, the insulin has run its course. Consider the total of hours between the bolus and the flattening out of the curve's tail to get your active insulin time. How simple was that?

Oh. Merely, if it's starting to ascent a trifle like you reported to Maine sometimes happens, so things just got more complicated. Because a rise trine hours downstream of a meal is remote to be caused by the meal—unless the meal was something with a gross ton of fat in it like a family sized, double-meat, additional-high mallow pizza that you ate all by yourself. (Hey, it happens.) If it isn't caused by the meal, then it moldiness be caused by something other.

Can you hazard what?

Well, in the absence of food, grippe, fleeing from feral flamingos, fending off a fennec fox, or fighting flying fish… sorry… I got carried away… In the absence of all the things that we know can causal agency blood glucose to go up, the only odd culprit is insufficient basic insulin. A rise three hours or more downriver of a typical repast usually signals a deficit in basal insulin during that time period.

By the way, Walsh himself recommends examination the insulin action time in a varied way. Helium advocates pouring what he calls a "expectorate" period with no bolus of any kind for five hours and no nutrient for three hours—citing research that says most carbs only raise BGL for unity to two-and-a-half hours—that leaves you above 250 milligram/dL. Presumably, two hours into the no-bolus zone, you are to run through a small amount of carbs to recruit your BGL. Anyway, the idea is to be at a "clean" 250 with none bolus or carbs live. That sets the arrange. Then you take a correction and wait and see what happens. The beauty of this come nea is that you can stamp out two birds with one gem: you are testing your combat-ready insulin time and your fudge factor ingredien at the same time. Walsh says to do this test three times to "see to it accuracy" and has complete the "ask your doc prototypal, blah, blah, rant" disclaimers attached.

Gary Scheiner, in the re-issue of his bodily fluid book, Think out Like a Pancreas, offers U.S. other alternate. He suggests that you "label your insulin with radioactive dye and see how long it takes for your body to stop glowing."

It should beryllium pointed out that Gary has a pretty damn fine humour.

His back up keep-it-simple plan is "check your blood dough all thirty proceedings after giving a chastisement bolus and and so see how nightlong information technology takes for the origin sugar to stop dropping." He advises no food, boluses, or exercise until you flatline (so to speak); as to remove some variables that might throw off your analysis.

Healthy, I've run around out of time, Amanda (in more to a lesser degree three hours!), but is it possible your active insulin time is to a lesser degree what's "authoritative" for "all but" of your endo's patients? Damn right, it could constitute! Only only clock time will tell. My advice is to take Walsh's advice. The "ask your doc first, rant, blah, blah" advice that is—and so run whatever of the tests higher up to find your very possess active insulin time.

This is non a medical exam advice column. We are PWDs freely and openly sharing the wisdom of our composed experiences — our been-there-done-that knowledge from the trenches. But we are not MDs, RNs, NPs, PAs, CDEs, or partridges in pear trees. Bottom melody: we are entirely a small part of your totality prescription. You still need the professional advice, discussion, and deal of a licensed medical exam professional.