I’ve now had the pump and CGM for 48hrs and I have started to notice a pattern after I eat. My BG rises steadily from shortly after I eat carbs, and peaks slightly 30-40 minutes after eating. Interesting. Seems that carbs hit my bloodstream pretty fast – within minutes in fact – so my body is cranking up insulin secretion straight away.
This is good to know, especially in relation to what we know about the time/action profile of synthetic insulins; the fastest acting insulins available start to work after about 20 minutes and don’t peak until around the 90 minute mark.
If you watch a CGM or a flash glucose monitor, you will have likely seen significant post-meal rises while you’re waiting for the insulin to kick in. What can we do about this? Well, we can’t change the insulin we have to work with (although they’re working on ultra-rapid and deep lung delivery insulins right now which will speed things up), but we do have control over when we take it.
If you’re seeing big post-meal spikes, you may want to explore experimenting with injection/bolus timing – such as taking insulin earlier than immediately pre-meal. Here’s a great article from MySugr on pre-bolusing to offset those big spikes, and better match the insulin peak to a carb curve.