Thursday, 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.

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