Continuing the discussion from Dexcom numbers not as close as I'd like:
@Terry4 I’ve been experimenting with this, but so far I get wildly disparate results, even if I’m stable for a few hours beforehand and not too high or too low. For instance, before dinner the day before yesterday, it was 20 minutes before the line bent down; yesterday it took just over an hour. Yesterday my lunchtime bolus kicked in at 10 minutes. Today, 40 minutes after, I’m still staring at my lunch, waiting. Makes it hard to plan …
But my question is: do you do the same time test with food/carb but no bolus, to see when food kicks in and then match the two times? If you start to eat 30 minutes after your dinner bolus, does that mean your food also kicks in at 30 minutes, or a little earlier? Or is it too variable to really pin down? (Or am I overthinking everything?)
That would be interesting enough to test. Of course, it’s going to vary depending on the content of the meal. Carbs hit your blood much more quickly than protein does. Etc., etc., etc. So if you wanted to compile a really good set of guidelines to work from, you’d need to test different meal types and record the results separately.
No, I have not done food without a bolus test. I don’t want to spend many hours afterward cleaning up hyperglycemia. The exact timing of food depends on the content of the meal and other factors like exercise, sleep, and stress. But when I use an appropriate amount of insulin given at an optimal pre-bolus time then I see a nice post meal glucose trace on my CGM. That observation bundles in the action time of the food.
One thing that comes to mind with your situation is your basal insulin. An appropriate basal insulin is crucial to build accurate meal and correction boluses. If your basal insulin needs are not well matched to your metabolism then you can easily and incorrectly ascribe the wrong conclusion about your meal insulin timing. Can you skip a meal and find your blood glucose stays relatively flat and in-range? You’re not likely to get the perfect basal match but being close is important. Besides, even if you did happen onto the perfect basal match, your body’s needs are not static.
It does vary, but not usually enough to make a difference. Other factors like being sick or not maintaining my daily exercise can interfere with metabolism predictability. I even found that low or high blood sugar excursions 24 hours before will tend to pull BGs in that direction, a metabolic echo of sorts.
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Yes, I’ve suspected this, and I’m working on tweaking them. I’ve done a few basal assessments at various times of day, but my ratios have changed significantly since then, so thanks for the nudge.
There are just so many variables. The ones you mention, of course, and then in my house new recipes are always being tried, and the time of dinner, especially, can vary by several hours – and just the fact that I find this a complication indicates that the basals aren’t quite right yet.
I just wondered how a person determined these times. Seeing when insulin starts to work is easy enough with a CGM, but that time has to roughly match when the meal you’re pre-bolusing for is going to start to work – otherwise you’ll go too low or too high. Maybe “roughly” is the operative word. It’ll all balance out at the end in the end. With luck.
It’s not perfect, but I have several timing strategies I use depending on proportion of fast acting carbs in what I’m eating that range from pre-bolusing of 30-40 min (a bunch of fast-acting carbs in the mix) to taking insulin after eating (for meals that are pretty much all protein and fat). But yeah, it’s a rough system, and it’s why sticking low(er) carb is easier, since then it’s less insulin anyway, so if it’s off, it’s not by much. I’ve come up with my guidelines based on trial and (lots of) error.
Wanted to add a stray thought on this topic: really intense exercise can alter my glucose metabolism for 48 hours or more. This has me a bit worried for July. I finally see an Endo, and I expect she’ll want me to start on very small dose of basal and perhaps mealtime insulin for when I eat a few carbs. I’m more than a bit worried about my pattern of BG and eating and how much it varies due to exercise.
Am I going to have to exercise consistently, for the same amount of time, etc. in order to dial in a proper bolus or basal rate? Although I exercise a lot now, I’m a bit here and there in terms of timing and intensity due to how frequently I travel.
I am very Insulin sensitive and although I pre-bolus 10-15 minutes, I cannot wait for the bend if my premeal BG are close to normal. Once the bend starts, I go low pretty quickly. If I am high, then I prebolus a long time ahead and try to wait to eat until my BG is approaching my target range before eating. What works well for me in the morning is to take a small bolus when ai get out of bed to counteract morning hormones and then later reduce my breakfast bolus by a portion of that bolus. Somehow that little bit of insulin on board helps to smooth out the BG rise from my breakfast.
