Somogyi effect, rebound and dexcom g4 cgms?


Could you post several different graphs that show different somogyi patterns(rebounds)? and all the comprehensive tips... So far I use my cgms sensors since 7 days and I didn't correct yet the rebounds. I even catched some rebounds during daytime..

I use cgms dexcom g4 but I dont use newer version. As I know it's 13% accurate in low bg.
I set my low cgms alert on 70 mg/dl.... Do you think I should set my alarm to higher level to avoid the rebounds ? As soon I hear my alarm, I eat 4 medjool dates .. It some minutes before I pick my medjool in refrigerator... do you think it would be better to put my dates next my bedside.. I could take my dates more fast...

I notice sometimes I can wake-up with vibration immediately but sometimes it takes longer time till I hear the sound alarm on cgms.

The pattern I noticed in my graph..if I dont correct enough fast my hypo.. It induce a rebound..and more I correct in late.. more the rebound is strong... as high as 360 mg/dl. In case of rebound, i have strong insulin resistance till noon.

Is it 13% enough accurate to catch early a rebound? or I will need to get newer update absolutely.

Feel free to share your experiences and tips.. I need to resolve my rebounds as fast as possible..

Thank you for your help so much!

Thank you

James do you have access to glucose tablets? Also, do you know the approximate carbohydrate content of the dates? From your description, you might be over-treating your hypos with too many carbs and possibly they take too long to start acting.

Are you doing a fingerstick blood glucose test 15 - 20 minutes after you treat for a low? The Dexcom will read low for much longer than it actually takes for your blood glucose to rise, since it is reading your interstitial fluid.

The Somogyi or rebound effect is going to vary for each person. If you are having a lot of low episodes, you will deplete your store of glycogen and the rebound will be less pronounced.


Yes I know the content of carbs of my dates. and I double checked with glucometer..
Yes I know a normal delay between 7 mins to 10 mins dexcom company said me.
Yes I tested with a lot of fingerstick while I have an hypo..if I didnt catch hypo enough early. Hypo could stay 1hours in interstitial fluid.. or even a little more before it starts to move. but in in blood glucose it starts to move in some minutes.

If I catch hypo early, interstial fluid will start to rise fast in 7minutes to 15 minutes approx.

but more I catch hypo late. more interstial fluid will stay low long time without any increase ..1hours to 1:30 hours in low..

Usually I have on rebound during night.. and I could hav up tree reboundds in total. I take 3 meals daily .. I ate plenty of carb.. I dont doubt my glycogen is full most of time. after one night rebound, I noticed insulin resistance that will last till noon..and sometimes till evening.


I set my low alarm value at 80, then decide what to do. If I am going down, I will take a small correction. If I'm stable and don't have anything requiring exercise planned, I may hang out there for a while. If I am going shopping, for instance, I will definitely correct at 80.

For they HYPO ALERT setting:
If you are noticing that you have a more severe reaction when it goes to 70 or below, set it to alert at 80.
This will buy you some time to make a proper sandwich or to have a snack that will be more kind to you instead of treating a hypo with something so sugar filled as dates.
While you may have an approximate understanding of the sugars in dates, it really is the wrong thing to use for treating a hypo event. The sugar content can vary greatly from one to the next and make a hyper-glycemic even much more likely. Instead, try to keep orange juice in the house and for emergency use, glucose tabs.
These things will treat a hypo and provide a more controlled result.
The dates you are using are approximately 5-7g of carb each. So while the amount of carb may be ok for you, the way it absorbs into your body is very different since you have to go through the process of digestion first.
With orange juice or glucose tabs, they will get into your system VERY quickly and prevent you still having that "low" feeling that can lead to over-treating.

For the alert from Dexcom:

The first time, it is ONLY a vibration alert.
After 15 minutes (if left on the default setting) it will vibrate again and then do a brief sound alert.
Many recommend putting the unit in a glass or a bowl along with some loose change so that the alert is more easily noticed. Give this a try and see how it works for you.

The new 505 software update for the Dexom G4 Platinum series is indeed more accurate. The mean increase in accuracy is 9% according to the papers on it.
I would recommend updating with the help of a Dexcom rep over the phone to walk you through it. I did not ice better accuracy in my entire range as well as better detection and results in the first 24-48 hours after sensor insertion.

Remember that you must carefully calibrate your unit. There are many other posts that can help in properly doing this so I will not repeat them. You can also check your literature that came with it and it will go over the process as well in more detail.
Just remember that the most important thing is to do a PROPER finger stick test to get the best results. Wash hands, use alcohol swab, stick finger, test blood.

I hope this helps.

Try not to focus on the rebound, just on identifying low blood sugars and changing insulin dosing to avoid lows in the future. No lows = no rebound. Re low alarm, it is more about your comfort. Once you trust the device more you may want to actually lower not increase the low bg level. Keep in mind, non diabetics can go as low as 55 with no symptoms and this is still normal.
70 is a very normal blood sugar, providing ... it is not going lower.
Depending how do you feel at those levels, how fast your numbers are changing , what is your experience with low bs, alarm will be set differently.
I started with 70-200, then 65-180, now 60-150.
I have friends with frequent, unpredictable, bad lows, their low alarm is set at 100.