The Dawn Phenomenon

nobimbo · 08-14-2003, 01:03 PM

Hi all,

I found out about something recently some of you may be interested in. For those of you who take regular Met (not the time released Glucophage) with your meals like I do, you may be having a pre-dawn spike in your insulin levels that you are not aware of called "Dawn Phenomenon". (This can happen in non-diabetics or diabetics). So although your Met may be working for you during the day, you may be having an insulin spike overnight that could mess with your other hormones. If you are not diabetic and do not test your blood sugars at home, you wouldn't be aware of this.

I just started testing my blood sugars at home two weeks ago, although I have been diagnosed with type II diabetes for two years. My doctor never told me to test at home, but I decided I wanted to start doing it (I've just come out of denial about the whole thing). Anyway, I found that my morning (fasting) blood sugars were always high (<110 is considered normal), but any other time of the day I tested they were very normal. This didn't make sense to me, since that's the time I go the longest without eating, and I thought it was food that made the blood sugars spike. When I found out about the Dawn Phenomenon I knew that was the answer (see below)! Two nights ago I checked it out the way it said (woke up in the middle of the night and tested it and it was 102). When I woke up 3 hours later my blood sugar was 134 (over 120 is considered diabetic, less than 110 is considered normal, 110-120 is pre-diabetic). I found out one of the things you can do to prevent this is to eat a little something before going to bed. So last night I saved 2 points and ate right before bed, and this morning my bs was 109!!

Although this post might seem better suited for the diabetes forum, I started thinking that this could have implications for anyone taking Met for insulin resistance. I am going to ask my doc about starting Glucophage XR since I seem to have this Dawn Phenomenon thing, and that will probably help to keep my glucose/insulin more stable overnight. I was thinking that even if I wasn't diabetic I would probably want to use a home glucose monitor to keep track of things while taking Met, and I wonder why that isn't suggested by docs for non-diabetic PCOS women on Met? Anyway, here's some info about the Dawn Phenomenon:

Dawn phenomenon refers to increased glucose production and insulin resistance brought on by the release of counterregulatory hormones in the early morning hours near waking. It happens in normal people as well as in diabetics; in nondiabetics it shows up as measurably increased insulin secretion around dawn. Dawn phenomenon is variable in strength both within the population and over time in individuals. It can show up as either high fasting glucose levels or an increased insulin requirement to cover breakfast compared to equivalent meals at other times of day.

The best way to sort it out is to test every couple of hours from bedtime to morning. If it is stable all night, but rises sharply sometime before you wake in the morning, it is dawn phenomenon.

Linda

christyz · 08-14-2003, 02:52 PM

Thanks for the info on Dawn Phenomenon, Linda....definetly applicable for us on Met. Most people, diabetic or not, exhibit some Dawn Phenomenon..it's the circadian rhythm that wakes you up and tells the liver to release stored glucose to give you energy to start the day. Most Dr's aren't too concerned about a slight increase, but as your own levels indicate, notably high sugars in that period are something to gain control of.

Your tips for helping DP are great...here are some others:

Try eating no food after dinner. This works for people whose Dawn Phenomenon isn't very strong. Basically, it lowers their baseline BG, so that when DP does hit them, the increase keeps them below a certain level, usually 120 (6.7).

Try eating a small snack of fat and protein before bed. Most find that a tablespoon of peanut butter, some cheese ot cottage cheese, or meat helps. The theory here is that the slow-digesting fat and protein holds their BG high enough overnight to avoid Somogyi Effect (a high due BG to a low overnight).

Eventually, you will learn how the two approaches above work for you. Hopefully, you will set personal targets to guide you, eg., if my BG is below a certain target, then eat a snack before bed. If it's over a certain target, then you don't.

Lastly, EAT BREAKFAST. The resulting increase in blood glucose from food will often turn off the continued rise. If you don't, some diabetics will continue to rise until 10-11 am.

Metformin is often very effective in limiting Dawn Phenomenon for Type-2s and insulin resistant Type-1s. (Of course, Type-1s can adjust their basal (slow) insulin regimen to account for Dawn Phenomenon).

nobimbo · 08-14-2003, 03:00 PM

Thanks so much Christy! I have learned so much from this site. I wonder why more docs aren't informing their patients of this. I found this out on a diabetic message board, and many other of the diabetics there had never heard of it.

One thing I was wondering is, if someone who is really non-diabetic has a fasting glucose test at the doctor's office, and they are someone who experiences the Dawn Phenomenon, might they be incorrectly diagnosed with diabetes? My doc diagnosed me after two fasting blood sugars that were high, with no other tests. (Oops, there goes that denial thing again, lol!)

Linda

christyz · 08-14-2003, 03:09 PM

Quote:

One thing I was wondering is, if someone who is really non-diabetic has a fasting glucose test at the doctor's office, and they are someone who experiences the Dawn Phenomenon, might they be incorrectly diagnosed with diabetes? My doc diagnosed me after two fasting blood sugars that were high, with no other tests. (Oops, there goes that denial thing again, lol!)

My guess is that if the value comes back High, they test during the day as well, to see if this is pattern. When I was pregnant with my son, my FG came back high and my Dr had me test my BG all day for few days. Since those came back fine, i was considered borderline Gestational Diabetes. I imagine one test value alone would not be lead to a diagnosis...that they would run a fasting insulin or GTT as well. You likely have more knowledge on that having been diagnosed yourself.

It sounds like you are snapping out of your denial by writing all this, so I'm not worried about you.

sweeterthenmost · 08-15-2003, 06:07 AM

Linda

I would consider it very irresponsable to diagnose a case of diabetes based on 2 fasting blood levels.

Most doctors, when the levels are borderline or in the lower range of diabetes, will request , first an HbA1c and then have you chart your blood levels several times a day for weeks. The only time that a correct diagnosis of diabetes can be made on one fasting BS is if the numbers are out of the ball park (for instance I was tested at 374 and by then I was dumping sugar into My urine as well as expereincing all the classic signs of diabetes) so it was quite obvious that I was diabetic. But my doctor still required all the tests I mentioned above before he would give an "official" diagnosis.

So I would do a bit more follow up with your doctor and see if he will be a bit more thorough in his examination and testing...

Best of luck to you

nobimbo · 08-15-2003, 09:42 AM

Thanks for your response. I think why he was so quick to diagnose me as diabetic is because he's always said I will be eventually. My mom had it, her father had it, my dad's sister had it, I am overweight, etc.

The first time my fasting blood sugar was high (210) was 2 weeks after my mom died. He wrote me a letter and told me to come back for retesting but I waited a year. I figured it was all the stress I was under the weeks before that test, and I know stress can elevate sugar levels.

The next year my fasting glucose was 164. I was also having typical symptoms...excessive thirst, urination, and I was actually starting to lose weight without really trying. Also, I was 45 and had been suffering from PCOS (and insulin resistance) for 23 years already.

I have read that the diagnosis for diabetes can result from two separate elevated fasting blood glucose levels. I really wish now though that he would have had me monitor my own blood sugars at home for a few weeks before I started medication to really know for sure. After finding out about the Dawn Phenomenon, I really wonder now how many people are falsely diagnosed.

Linda