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Fasting BG rising - when to worry

C

Carpetsalesman

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Hi, I had some classic symptoms during the lockdown, and rather than go to the doctor I got a BG test kit and came out at 6.4 fasting.

I kinda think that I was constipated because of dehydration, so I was eating tonnes of high fibre cereal (also high carb high sugar - thanks cereal marketing depts), which was driving my BG up, which was making me more dehydrated, so extra cereal!. I was then going out and feeling a bit sick and weak, and eating sweets because I thought I was having a low calorie breakfast and needed a boost!

Over three weeks I went brutally low carb, felt great, and dragged rating down to 4.8. But in the last three days it’s rising again and is back at 5.8. Waking up feeling dehydrated.

I suppose my main question is, what is the horizon over which I should expect to take the numbers seriously? If I’m at 6.0 on low carb in three months? Or in another three days? I just don’t have a feeling for the natural variability of the results over the short term, or even what short term really is.

Any comments on this or anything else welcome.
 
Yeah I get the ranges, hence I think I am probably pre and hence why I am here.

I’m doing the diet and exercise, and after some success it’s now bouncing up again. Is three days of upswing neither here nor there and it’s all about the long term?

Also, anyone here got thalassemia beta?
 
For the moment, forget fasting blood sugars. It's hot, you might not be sleeping soundly, and if you wake a few times during the night your liver'll start dumping glucose. Also, if it's hot, blood sugars tend to do slightly odd things.... All in all, we can't really tell anything from your fasting blood sugars. What would be rather informative, would be if you tested before a meal and 2 hours after the first bite. You're aiming for a rise of no more than 2.0 mmol/l between those two, and should be somewhere under 8,5 over all, though there's some leeway in that number.

I had to look up TB, so didn't know what it was, but it is actually relevant should you go to a doc for assistance: A HbA1c (a three month average that's used for diagnosis and check-ups) gets skewed if you're anemic for whatever reason.

Hope that helps!
Jo
 

Very helpful, thanks!
 

Just jumped from 5.8 to 6.3 after a very dreary low carb lunch. I guess that’s not so bad. But I’m still peeing like a racehorse!
 
Carpetsalesman said:
Just jumped from 5.8 to 6.3 after a very dreary low carb lunch. I guess that’s not so bad. But I’m still peeing like a racehorse!
Click to expand...
Carbs retain water. With no carbs, the excess water is leaving your system too. Hence the peeing like mad. That'll pass.

The pre and post prandial are quite superb, but ah... Why dreary? If you eat stuff you like, it's easier to keep up.
 
Hmm, now 7.6 after a salad and the inside of a quiche - maybe 30g carb total. That’s the highest I’ve ever scored. And I’ve walked 5 miles this afternoon.

I’m doing exactly the same sensible things, but the ****** thing has suddenly stopped slowly going down and abruptly started going up!

A week ago I thought I’d be waking up at about 4.5 by now, suddenly it looks like I’ll be lucky if I’m under six.

This is a funny old business.

post edited to comply with forum rules on language use

*my apologies for the fruity language, although for the curious it was nothing too post-watershed
 
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https://www.dietdoctor.com/low-carb/fasting-blood-glucose-higher might help. My FBG's are usually in fives and sixes these days, been keto for two years and LCHF 2 years before that. Not worried about it.
 
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That’s interesting thanks.

My fasting is still rising slowly and steadily despite being on about 50g of carb per day. Now fasting at 6.0, almost back when I started this a month ago. 30g carb lunch had me up at 7.5 today.

So frustrating, I thought I’d cracked the code two weeks ago! And I feel better than I can remember so something is going on with BG.

Looks like this ends with a trip to the GP to ask for a look at the corresponding insulin levels.

If I can remember, I’ll keep this updated to memorialise what happens for someone who has similar symptoms one day.
 
I meant total carbs, just the number on the food label next to carbs. I think 50g might have been understating it a bit.

The last week FBG has stabilised at around 5.6-5.8. And not much movement during the day either on this diet. I think the changes in either direction have stalled and levelled off. I appreciate that these are not scary numbers for old lags like you lot. And after a month the diet seems more inconvenient rather than impossible if this is what it’s going to take ongoing.

Anyway, blood test at the doctor’s this week and whatever else the nhs sees fit to inflict on me.
 

Carpetsalesman for most people, the NHS views a HbA1c test as the primary diagnostic test for T2 diabetes. Other tests are used for other types of diabetes.

I would just suggest that you ensure that your GP is remembering about your blood disorder when deciding which tests you might need. For some blood disorders, the HbA1c isn't to accurate, so they use other tests; primarily a fructosamine test, for T2.

Good luck with the tests.
 
Update: blood test returned "normal" HbA1C in the context of my blood complaint. However it also returned high potassium which is a symptom of kidney damage, which of course is a complication of diabetes. GP believes the test result may be wrong, hence I will repeat the test.

In the meantime I am now back at FBG 6.2 which is nearly where I started, despite six weeks on about 50g carb a day and at least a 14hr fast every night. Not much change during the day as you might expect on 50g, but after initial success, whatever I do it seems to keep slowly ticking back up into the pre zone.

Obviously now everyone thinks I am totally self obsessed and either suffering from munchausen syndrome or total hypochondriac. I am reminded of Spike Milligan's headstone - "I told you I was ill!"
 
For anyone who sees this in the future when troubleshooting their own results:
- The 2nd potassium test came back normal
- HbA1C was 5.5/37
So, I'm not diabetic...

It's been a strange journey so far with no real closure. Started at FBG 6.4, and the first two weeks of low carb were a revelation, I went to 4.8 and felt ten years younger, really felt amazing. Then FBG slowly tracked upwards and stabilised at around 5.7/5.8, which is not "normal" for a non-diabetic on 50g/carb per day, but it is what it is.

I charted my scores and it's weird seeing the FBG start high, shoot down, come back up and then flatline. The full scores (including those during the day) are even weirder. They start off zig zagging up and down like crazy, and then you can see the variances get smaller and smaller and by now almost nothing happens during the day, it goes up by about 0.5, it goes down by about 0.5. The variance is just leveling out into nothing.

I still feel a little better than I did before, but obviously with a radically restricted diet and pin-cushion fingers!

I don't really understand how Thalassemia Beta interacts with blood glucose, and probably never will under the NHS because my scores are acceptable. It's occurred to me that maybe I might have lupus, I have some other symptoms that relate to lupus but I can't see a route through the NHS to get taken seriously anymore.

I'll see what happens over time and keep an eye on the scores. Thanks to everyone here for any guidance I've received.
 
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Update:

I'm 50g/day low carb for four months now, with FBG now typically between 5.8 and 6.8. Not overweight.

After experimenting with a bowl of cereal which spiked me to 10.5, I asked the doctor for another test, which was the old fashioned glucose tolerance test. This is the one where they take your fasting blood, give you 75g of glucose and test again in 2 hours time.

I opened the day at 5.5 which is unusually low. Five minutes before I walked into the doctor to have the 2nd test I did a fingerprick and scored 9.5.

Later that day the doctor called me with the good news that I am unequivocally not diabetic. Opening blood 5.5, matching the meter. Two hour blood was... 5.5!

"But what about my fingerprick test, I measured 9.5 five minutes before your test that says 5.5, how can that be?"

The doctor kindly explained that I've had the gold standard clinical test for diabetes, and passed perfectly. There is no reason for further investigation. And he obviously can't explain a result I'm taking with a £20 kit in my car. And I understand this completely. An hour later I nearly fainted in the street, managed to get something to eat, and when I got home and did another test an hour later I was at 4.6.

At this stage I have no idea what is going on except that something is going on and it is not good.
 
I've concluded that the finger prick machines we use can give some randomly high or (more rarely) low numbers. On a number of occasions I've done a test and it's been 6.8, say, and then done another one immediately after with the same drop of blood and it's 9.8 or something of that order. If I do a third it will be close to the first one.
 
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