Helmut:
This is absolutely fascinating. I’ve been looking for CGM data from a “normal non-diabetic” population for quite a while and you’ve found it. Using the Dex data I found the following facts about non-diabetics particularly interesting:
- Average A1C of 5.3
- Average daytime bg of 101
- Average nightime bg of 98
- Average high daytime bg 163
- Average high nightime bg 128
- Average low daytime bg 67
- Average low nightime bg 72
- Distribution - < 70 7.2%, 71-120 65.9%, >120 17.0%
- Standard deviation 26.7
I’ve matched this data up against my Dexcom numbers and am finally able to benchmark my performance. Noteworthy to me is that these numbers are not too far off mine, and considering that your A1C is around the normal level shown, I would guess that your profile is very similar to that of a normal person. I’d always assumed that there would be much lower variability in a normal person, and that substantial amounts of time would be spent in the 80’s but that does not appear to be the case. I’m going to slice and dice the data further as it pertains to my own numbers but wanted to thank you for this great stuff.
Trust all is well.
Mike.
Hi Helmut,
Great find!
Here is a similar study with a slide presentation of the results. Click on a slide to enlarge it.
What is Normal Glucose? – Continuous Glucose Monitoring Data from Healthy Subjects
Nice! I like the slide which shows that with n=21 the pre-prandial’s are all around 80 (as one might expect) with the average bg max as follows: bfast - 130, lunch - 118 and dinner - 123. These are attainable numbers for a diabetic with careful carb counting and the correct I:C ratio. I know I’ll always be a T1 diabetic but I’m going to try like heck to emulate the results of a normal pancreas…Thanks for sharing. Mike.
sorry, I added up incorrectly - corrected normal range numbers below :
<70 8.5%
71-120 65.9%
>120 24.8%
Hi Mike,
I agree with you that these numbers are attainable. Every now and then, I fall off the wagon. I never get 100% on the diabetic control exam, but sometimes close enough is good enough.
My best to you with your control.
Ricardo:
Thanks for your good wishes and for serving up the great data. It sounds like you are doing very well and as my golf instructor says “this is not a game of perfect…”. To be successful with diabetes management one needs a slightly obsessive streak but this same obsessiveness, in my experience, can become an obstacle unto itself. Balance is the key - easier said than done. I’m glad to now have some benchmarking numbers as it helps provide some concrete goals. Thankfully the dexcom for its part contributes plenty of raw data to assess progress.
Best of luck to you in your pursuit of your desired level of control.
Mike.
Mike,
Thanks for pointing out that the appendix contains a lot of data. The results vary between DexCom, MM and Navigator. I am inclined to give more credibility to the measurements of the Navigator than the DexCom. The DexCom (not DexCom 7+) was not as accurate as the Navigator.
Based on the Navigator the time spent above 120 mg/dl is 5.4%. I spend about 15% of the time above 120 mg/dl. Close, but no cigar.
6415-onlineappendix.pdf (295 KB)
Ricardo,
Thanks for posting the link to this presentation. I had a totally wrong impression of what is normal. I thought that BG of healthy people was 83 mg/dl almost all the time. It is good to know that my BG is almost normal. I can stop beating myself up.
Helmut: Thanks for pointing out the difference between the old Dexcom data and what might be expected from a Dex 7+. I’ve gone back to re-evaluate my numbers in this context and realize I have to work harder to get closer to these benchmark levels using the navigator numbers. In particular, the navigator data suggests only 1.1% is spent in the <70 category for normal people and I’m spending 21% in this territory. I’m less far off on the higher end with navigator showing normal people spend 6% of the time >120 when my chart for may has me at 7%. So overall this benchmarking tells me I need to focus on reducing my time spent low. I’ve been trying to find this benchmarking data for quite a while, even attempting to convince a non-diabetic neighbor to wear a CGM for a few days to provide me a chart, so I’m much heartened to have real numbers to which I can refer. Thanks again. Mike.
Mike, I applaud your efforts to keep your bG WNL, but 21% under 70 sounds dangerous to me. I’ve noticed that my brain and body work best in the 100-120 range. Did you maintain an awareness of hypoglycemia?
Etta: I think my numbers might be a bit misleading. Although the Dex 7+ is very accurate for me during the day, the night time numbers always run significantly low (something to do with the fact that I don’t move much during sleep so the interstitial fluid pools and gets glucose depleted around the dex sensor). Therefore my night time numbers might be consistently around 65-70 per the dex when in reality they are probably 85-95. Thus I don’t believe I really spend 21% of the time in this hypo range. Nontheless, I do have a tendency to agressive bolus which does result in some legitimate day time lows from time to time. I am still hypo aware although the symptoms start at a lower number than before but I always get a symptomatic warning. My regimen is a work in progress, as it is with most of us, but it’s great to have “normal” numbers against which to attempt to benchmark. Mike.
Mike, thanks for the explanation, I understand completely.
I hate it when the numbers run (erroneously) low during the night, causing the alarm to go off needlessly. Typically that happens to me the first (and sometimes second) night with a new sensor that hasn’t yet been adequately “trained.”
I had time to digest the numbers. The most important number for me is the standard deviation. From various sources I know that
SD is 50-60 for a typical T1,
SD is 20-30 for a typical T2,
SD is 10-15 for a healthy person.
Thanks to my gadgets I manage to run with the T2s. What does this mean?
I can keep my BG in a 50 mg/dl range for about 70% of the time. Let’s assume I chose this range to be 70-120 mg/dl. This means that 30% of the time my BG will be either above or below 70-120 mg/dl. During the last 3 months my BG was 14% below 70 mg/dl and 15% above 120 mg/dl.
This is as good as it gets for me unless I improve my BD standard deviation. I know how to do that (low carb). I am just not motivated to go there.