Increased insulin sensitivity with better BG control?

I'd like to hear from others about this... I recently got my BG under tight control (A1c 6.3%) from being wildly out of control (A1c 11%).

I started on a pump about 2 months ago now. All settings were working fine for the first month or so.

However, as I've had BG under good control, I've been having more hypos. They're increasing in frequency. I'm T2, don't run much of a basal -- just enough to stay flat during fasting periods between meals (presumably giving my pancreas a rest, in theory), and bolusing at 1:4 was working fine.

For the few weeks, the hypos have been gradually more frequent, and deeper. This morning was the worst -- not a deep hypo, but a persistent one. Would up eating 25g of skittle-carbs in three batches, each time getting a blip up into the 70s, then gradually back down into the 60s again. Now I'm about to go have lunch, which will correct that one for good.

Bumped the I:C to 1:5 before lunch. We'll see what happens.

Anyone else see this phenomena after getting good control? FHS -- especially interested in your experience. Also any other T2's that have seen this, please share!

Thanks, all!

I'm Type 1, but I've read about this happening. It may even be happening to me, although I'm not sure how much of my experience is just that I'm actually having insulin absorbed properly, and how much is really increased insulin sensitivity.

Since I switched infusion sets about six weeks ago, my pump settings have been steadily dropping despite still having a ton of lows. I thought maybe I had hit my limit since the past 24 hours I've had some highs (along with lows), but in hindsight I think my insulin needs are still dropping.

The day before yesterday I had my blood sugar spike to 13.9 (250 mg/dl), then drop to 2.5 (50 mg/dl), then spike to 11.5 (207 mg/dl). It was the end of day two of my infusion set (I change them every two days), so I thought maybe absorption might be weird for some reason. I changed sets, and overnight dropped to 2.8 (50 mg/dl), woke up at 6.9 (124 mg/dl), did a small correction and dropped to 2.3 (41 mg/dl) before breakfast, then spent the morning at 8-9 (140-160 mg/dl) and then spiked to 14.5 (261 mg/dl) before lunch for really NO reason. It reminded me so much of my readings before using cannula sets ... My infusion set was feeling irritated, so here's the great part about needle sets: I took it out and moved it a few centimetres to the left. The spot were it had been was definitely irritated, it wasn't itchy but was red and raised and felt hard. Maybe scar tissue (although I don't use my legs much). Anyway, since moving it I was down to 5.8 (104 mg/dl) within an hour and a half, and have not been higher, spending most of my time low again. I dropped to 2.9 (52 mg/dl) last night on the way home, ate a snack and was 4.0 (72 mg/dl) before bed, ate some chocolate with no bolus and still woke up at 2.8 (50 mg/dl) this morning.

I thought with the cluster of double digit numbers that maybe I had backed off too far on my pump settings. Since changing infusion sets my TDD basal has dropped from 32 units to 28, m I:C has gone from 1:6 to 1:10, and my ISF has gone from 1.2 (22 mg/dl) to 2.0 (36 mg/dl). But I'm now thinking the highs were just infusion set related, and since I've been mostly low a LOT (went through two tubes of glucose tablets in the past 24 hours) and am pretty much having readings of 2.8 (50 mg/dl) about twice a day now, I'm thinking I'm going to back off even more on pump settings.

Also, if you are losing any weight then insulin needs to decrease as weight decreases. So the combination of improved control and weight loss can definitely affect insulin resistance. This is why some Type 2s start insulin and are later able to discontinue it completely.

Thanks Jen! Interesting account. One disadvantage of the Omnipod... bad site, toss a good pod.

The only thing that will get me off insulin will be postprandial <=140 without insulin. Don't that will ever happen, no matter how thin I get :-)

The Cozmo 1800 pump used to have a feature where you could set different ISFs depending on your blood sugar level. So, if transient highs can result in insulin resistance, it makes sense that spending a lot of time high and then getting better control would lead to increased insulin sensitivity.

I don't think your experience is all that strange. Simply having high blood sugars can induce insulin resistance. Your body naturally responds to high blood sugars by downregulating the action of insulin. It protects our cells from being poisoned by high blood sugars (somewhat).

The other thing is that many people report that their insulin requirements drop when moving to a pump. I think that this has to do with an increased efficiency of delivery and getting. I've seen a number of people report this happening independent of improved control.

Insulin needs can change. Just when we think we have basal rates and insulin to carb ratios "dialed in," the game changes.

Are your lows before meals or after meals? If before, then you should look at your basal rates. If the lows come after eating then your insulin to carb ratio (I:C) may need adjustment. I try not to make insulin changes until a trend develops. That is, if it happens three times then it's a trend.

You may even observe that reducing basal rates or I:C may cause more lows. It doesn't make sense but falls under the heading of sometimes "less is more."

I've found that adjusting insulin delivery is best done by keeping a written record. There are enough factors invovled to inhibit your ability to "see the forest because of all the trees."

Another factor to examine is the duration of insulin action time setting for your pump. Most people using rapid acting analogs (Humalog, Novolog, Apidra) set this between 3 and 4.5 hours. People do vary. I set mine at 4.5 hours because I found unexplained lows during the fifth hour after eating. My pump would tell me I had no insulin on board but my BG nonetheless was dropping. This is a trail and error setting.

Have you read Pumping Insulin by Walsh or Think Like a Pancreas by Scheiner? Both of these books cover the nitty-gritty of pump use and will help in customizing your pump for your body. Most importantly, they will equip you with the ability to make ongoing changes as needed. Diabetes is a dynamic disease and responding to changing needs is a critical skill.

Good luck with your pumping. It's an incredibly useful and adjustable tool.

If my BG is off (low or high) when I'm fasting, which sounds like the case here, since you describe it as "persistent", I'd agree with Terry that adjusting your basal might be useful. If you have one rate, my "cheat" for the annoying morning situation is to crank it up in the AM and then down later on in the AM. I'd try that first, unless you are absolutely bottomed out on your rate and can't go any lower.

I agree with Brian as well that pumping is generally held to result in less insulin. I think that pumps just work better, once you allow for various issues that can arise through their use.

Didn't understand this, Brian. How does downregulating the the action of insulin (I read this as making it less effective, same as increased insulin resistance) protect tissues from high blood sugars? This would seem to increase that possibility.

Could you explain?

GLUT-4 works with insulin to transport glucose into our cells. Exercise increase the number of GLUT-4 transporters (createed by our cells) and conversely, high blood sugars reduce the number of GLUT-4 transporters. This is why exercise makes you more insulin sensitive and one of the reasons that hyperglycemia creates insulin resistance.

Hey Dave,

Sorry, missed this post.

Yeah, my hypos definitely went up as I got my BG back under control. My insulin sensitivity went up too, but I hit the gym pretty hard and generally ratcheted up my activity level a good bit as part of my management plan.

Also, keep in mind, at my worst level of control, other than taking my daily basal Lantus dose, I was pretty sporadic with my meal boluses and shot up blind most of the time when I did. If I tested more than 5 to 10 times a week, it was a banner week. Then, I went on the pod shortly after my A1cs bottomed out in the low 6s to high 5s.

I take ridiculously low amounts of insulin daily now, anywhere between .30 to .41 units/kg/day. A lot of that is just an artifact of staying really really active and switching over from MDI to a pump.

Grats to you!