May 15, 2008

When Going Low Makes You Go High: Mysteries of Counterregulation

If you use insulin, one of the weirder phenomena you're likely encounter as you work on normalizing your blood sugar is the way that when you use a bit too much insulin you'll see your blood sugar go up, not down.

This can be very confusing, and it is all the more confusing when you have to rely for help on doctors who aren't familiar with this phenomenon.

Counter-regulation is the official term for what is going on here. It refers to the built-in protective system most of us have that monitors our blood sugar level and, if it drops too low, causes the release of hormones that will cause our livers to dump some glucose into our blood streams to raise it back up again.

The hormones that do this are our old friends, the stress hormones. So often the only signal you get that you have experienced a bust of counter-regulation is that your heart speeds up, your pulse pounds and your blood pressure goes up.

By the time you feel any of those symptoms, your blood sugar will have risen, so testing it will often reveal a normal blood sugar. It's too late to catch the low that triggered the release of hormones.

A common time to experience a burst of counter-regulation is at 4AM, a time when blood sugar may naturally drop to its lowest level. If you wake up out of a deep sleep with your heart pounding this may have happened. Check your blood sugar and it will be higher than usual.

Even worse, after you've experienced counter-regulation you may be more insulin resistant than usual for a few hours.

All this sounds very simple, but several things complicate the issue.

1. The level your body believes to be "too low" may actually be a normal blood sugar.. This happens if you have been running high for a while, because your body defines "normal" as being whatever blood sugar level you've been living at and if that level has been high it may react with a burst of hormones to raise your blood sugar when it is at a perfectly healthy level.

Ignorant nutritionists often advise people with diabetes to eat carbs (and thus raise their blood sugars) to avoid these "liver dumps." In fact, that's the worst thing you can do. You want to keep working on lowering your blood sugar so that your body resets the "normal" thermostat to--duh--normal.

Though you might experience counter-regulatory bursts at first when you lower your blood sugar to normal levels, the more often you get your blood sugar down to normal--even if your body pushes your blood sugar back up--the lower that thermostat will be set. You just have to wait it out, keep lowering your blood sugar, and eventually you won't get those bursts when you "drop" to normal levels any more.

The strength of the counter-regulatory response varies from person to person. Mine is extremely strong and it took me literally months for my body to get used to the low 90s. And more months to get used to the 80s. But now I do not get counter-regulatory bursts until I'm in the low 70s, and that works for me.

2. If your blood sugar thermostat is set correctly, getting your basal insulin doses wrong can make your morning fasting blood sugar high, tempting you to add more basal insulin and resulting in more counter-regulation.

This one can be VERY hard to debug. Because my natural fasting blood sugar was around 108 for many years, I've learned, after a lot of observation, that if I use even so much as 1/4 unit too much basal insulin, I'll wake up with a pounding pulse and a blood sugar of 108. If I drop that 1/4 unit, I'll wake up at 86. I'm extremely sensitive to basal insulin. So most people will see that kind of difference in response to changes of 3-5 units.

But if you start increasing your basal insulin and see your blood sugar going up in the morning rather than down, it's worth testing the idea that you are using too much and lowering the dose, night by night, until you see it going down again.

3. Counter-regulation also occurs if your blood pressure drops. This can make it really tough to debug blood sugar highs. At the same time of night when you are prone to lows, your blood pressure drops, and if it is too low, your body will secrete stress hormones to push that blood pressure back into the safe zone. That also pushes up your blood sugar and figuring out what is causing that 4AM pulse pounding can be very tough indeed if you are also taking blood pressure medication.

To make it even more complex, lowering your blood sugar may cause your blood pressure to improve--as may cutting the carbs out of your diet. So just as you get your blood sugar near where it belongs, your blood pressure may drop and you may start having those bouts of early morning counter-regulation and wake up with your blood pressure--and sugar--higher.

Family doctors are very unlikely to understand this phenomenon at all and may make things worse by telling you to raise your blood pressure medication or insulin rather than lower it since both may be quite high after a burst of counter-regulation. Mine sent me off to a cardiologist when I developed a pounding pulse in response to what I only much later realized was a serious overdose of basal insulin. (About 3 times more than my body can handle.) The cardiologist never suggested that the problem might be counter-regulatory in nature, but instead wanted me to take a beta-blocker to lower my pulse. A beta blocker would have damped down the counter-regulation--and set me up to experience really dangerous lows since my body would no longer be correcting the response to too much insulin!

Counter-regulation is there for a reason. People with diabetes who experience a lot of lows eventually reset their blood sugar thermostats extremely low and can have extremely dangerous hypos.

How To Handle Counter-Regulatory Problems

If you take insulin and are experiencing counter-regulatory bursts do the following:

1. Check your blood sugar before you go to sleep. If it is near your morning target take a few grams of glucose before you go to bed and see if that solves the problem. That helps a lot for me. You can also try eating a protein snack before bed to provide some glucose for those early morning hours.

2. If the snack doesn't work try lowering your nighttime basal insulin dose by a small increment and see if your blood sugar goes higher, stays the same, or drops. If it stays the same, you can drop it a bit more. If it goes up, counter-regulation is probably not the problem. If it drops you might be on the right track.

3. Test your blood pressure with a meter at various times of day. If you see values in the low end of normal--90/60 for example, it is very likely you are dropping even lower at night. If so, talk with your doctor about lowering your blood pressure medicine.

4. If you are using Lantus and can't eliminate counter-regulation (I couldn't) ask your doctor if you can try switching to Levemir because it is shorter in action especially when used in smaller doses. With Levemir you can use a larger morning dose and a smaller night time dose, and that may avoid those 4AM lows.

5. If you have access to a CGMS you may be able to see late night lows you are otherwise missing. This is described in detail with several sample CGMS logs in the book, Type 1 Diabetes: A Guide for Children, Adolescents, Young Adults--and Their Caregivers. by Ragnar Hanas. It was only after reading this book a few years ago that I was finally able to figure out what was going on with my blood sugars since they so often went up, not down, when I used basal insulin.

6. Aim for a basal Level in the mid-80s. Setting your basal too low may eliminate counter-regulation problems, but it sets you up for dangerous hypos. If you are waking up in the low 70s every day you might be resetting your blood sugar thermostat at a level that keeps you from getting a helpful counter-regulatory response when you drop into the low 60s or lower.

8 comments:

melehundele said...

AHA! Another "AHA" moment courtesy of Jenny! :)

I may be combatting this issue...I guess it is no good sign that I am not sure if I am or not. I take Lantus and take half in the am and half before bed. I also take Novolog before bed to adjust down, if my bedtime number is too high.

Despite this, I am waking up with high fastings (110-141!) and my numbers stubbornly refuse to go down much despite morning Novolog, with or without breakfast, until morning Lantus kicks in around noon.

About a week ago I woke suddenly in the wee hours with my pulse pounding. I thought I was having a heart attack. This is all seeming to fit with your description...

mollyjade said...

This is exactly what my current endo tells me. The best way to stop reactive highs is to prevent the lows that cause them. We actually got my A1c to go down an entire percentage point by lowering my basal insulin and stopping the overnight lows.

I complained about the overnight lows for years to different doctors, and all they suggested was eating a larger snack at bedtime or reducing my lantus by a unit or two. It turned out I needed to cut my lantus almost by half.

Amalas said...

I've been wondering if this is what's been happening with me at dinner. My blood sugar would drop low/low-ish after eating, then would be high before bed. My guess is, like you said, it's just counter-regulation hormones combating that low, resulting in a high later on.

Jenny said...

Mollyjade,

That is really interesting!

I suspect that doctors have been overprescribing basal for years out of the belief that it is safer than using the meal time insulins.

It may also be that because so many of us people with diabetes are cutting back on the carbs the old formulas they were taught for coming up with basal/bolus don't work anymore.

For years I just thought I had some weird MODY thing that was keeping me from getting my fasting bg down with basal insulin. In fact, it was just that the dose I have to use is tiny. When it get it right, though, I drop from 120-something to 86. And that makes a difference in how effective my meal time insulin is too.

charakan said...

Hi,
Just stumbled up on this blog.Great work.I am a doc in India taking care of lot of Diabetes patients.Very few doctors not to mention about patients are aware of the correct management of these 'highs' and 'lows'.Hope more and more Diabetic patients will go through your blog and understand it

mollyjade said...

I honestly think it was inertia. I was diagnosed at age three in 1985, and besides switching to the newer insulins and adding a lunch time bolus, nothing about my care regimen changed until I started seeing my new endo in 2006. I had overnight lows most nights for 7 or 8 years under the care of three different doctors, and it only took the new endo 30 seconds to figure it out. Kinda pisses me off.

Trink said...

Nicely written up!

As you may remember I have had reactive hypoglycemia for possibly fifty years, which was mostly written off as "neurosis", "hypochondria" etc.

In my case using Jennifer's Advice

http://www.alt-support-diabetes.org/NewlyDiagnosed.htm

to control my carb input downwards to the point my BG stays pretty much in range has all but eliminated the symptoms. (And also brought my lipids and BP back in line).

I read a couple of disappointing papers on RH which completely miss the point: they state that RH should/must not be diagnosed in the absence of actual hypo numbers.

Well my experience is that it's not the BG per se but the *rate of change* that brings on the neuroendocrine dump which relates to the hypo *symptoms*: I've had more symptoms at 90 when I got there after a rapid BG drop than at 60 if I got there slowly. So it figures it would go the opposite way also.

It also struck me that RH is almost the exact opposite of Hypo Unawareness - where the BG drops into genuine hypo numbers but the body doesn't respond. So maybe us Reactive Hypoglycemics should interbreed with the Hypo-Unaware folks (I'm up for offers (G))

Issues like this don't show up unless you not only test but test at the right times and in the right way to discover rate of change issues rather than just static numbers, for which a loaner CGMS system would be ideal.

Boz said...

Thanks for the great info on the lows. It seems it hits me after I've been high for awhile, then get things under control for a few days. It strikes at almost any time for no reason. The last time was 2 hours after dinner, which was an eat on the run-fairly high carb meal. I was down to 48. The effects ie spacey, weak, blaugh feeling was terrible, and lasted till the next afternoon. Scary.