Not enough carbs?

[Beancounter298]

My fingerpick test first thing this morning was 4.9. I didn't have breakfast and had a very low carb lunch of cheese and yogurt. Just did another test prior to evening meal and the reading is 8.8. How can it have gone up so much when I've eaten only around 15g of carbs so far, and walked just under 9,000 steps? Is it possible that I should have eaten more carbs? My evening meal will be more carb heavy

 

[Leadinglights]

My fingerpick test first thing this morning was 4.9. I didn't have breakfast and had a very low carb lunch of cheese and yogurt. Just did another test prior to evening meal and the reading is 8.8. How can it have gone up so much when I've eaten only around 15g of carbs so far, and walked just under 9,000 steps? Is it possible that I should have eaten more carbs? My evening meal will be more carb heavy

Probably your liver being helpful in releasing glucose but in some people exercise can increase blood glucose in the short term.

 

[Martin.A]

My fingerpick test first thing this morning was 4.9. I didn't have breakfast and had a very low carb lunch of cheese and yogurt. Just did another test prior to evening meal and the reading is 8.8. How can it have gone up so much when I've eaten only around 15g of carbs so far, and walked just under 9,000 steps? Is it possible that I should have eaten more carbs? My evening meal will be more carb heavy

Switch hands and do a second test. That's what I do if I get an unexpected high or low. If the second test is the same or thereabouts I'll take it as correct and just take the average, but if it's very different I'll pick another finger and do a third to see which of the other two is the 'rogue' reading. To be honest you could test all six fingers and you would most likely get six different results.

 

[Beancounter298]

Switch hands and do a second test. That's what I do if I get an unexpected high or low. If the second test is the same or thereabouts I'll take it as correct and just take the average, but if it's very different I'll pick another finger and do a third to see which of the other two is the 'rogue' reading. To be honest you could test all six fingers and you would most likely get six different results.

Just done a test on a different finger and it's a 6.0, I'll take that!

 

[Drummer]

My fingerpick test first thing this morning was 4.9. I didn't have breakfast and had a very low carb lunch of cheese and yogurt. Just did another test prior to evening meal and the reading is 8.8. How can it have gone up so much when I've eaten only around 15g of carbs so far, and walked just under 9,000 steps? Is it possible that I should have eaten more carbs? My evening meal will be more carb heavy

Don't worry - we don't need carbs except to counteract glucose lowering medication.
If you are trusting your natural controls to keep things in order, then there is no need to be concerned.

 

[Lucyr]

Just done a test on a different finger and it's a 6.0, I'll take that!

Are you aware that you need to wash your hands before every fingerprick test?

 

[everydayupsanddowns]

Just done a test on a different finger and it's a 6.0, I'll take that!

Aha! Such good advice from @Martin.A and @Lucyr

I get so bound-up in all the imponderables of glucose juggling (and trying to second guess and post-rationalise what particular mistakes I might have made this time) that it’s really easy for me to forget to follow the manufacturers advice, follow proper testing procedure, and to recheck a reading if it seems a bit weird of unexpected.

Meters are great. But duff strips do happen (and traces of things on fingers etc). The ISO standards for meter accuracy only apply 95% of the time. 5% or readings can be anything at all!

 

[Martin.A]

Good example this morning @everydayupsanddowns - LH two 6's, including an unusually high one, RH two 5's, so ended up averaging all 4 and logging a 6.0 this morning.

 

[Docb]

Good reminder about reproducibility of test strips but I am not sure that your comment on the standards is quite right.

If you were to get a test solution of known glucose content and then do 100 tests with 100 strips randomly taken from the production line then you would expect a distribution of results. What the standard calls for is that 95% of those results should fall with 15% of the known value of the test solution. My guess it would be a normal distribution so most of the results would be much closer to the test solution value but if you do a enough testing you will inevitably get results which are way away from your test solution value. Nothing is wrong, its just the nature of testing and the random errors that occur in manufacture of test strips.

Apply that to blood and the reading you get are best thought of as a decent estimate of your blood glucose level. If like @Beancounter298 you get a result that seems odd (especially oddly high), then retest on another finger maybe after washing your hands. Thats what @martin A did. Taking the mean of a few results is good, taking a mean of 100 tests would be ideal although time consuming,expensive and a bit bloody.

@Beancounter298 - your two readings of 5 & 9 (as most will know I refuse to quote decimal numbers) are far enough apart to ask the question, is this real or something to do with random errors. A retest on the 9 would be in order because it is far from what you expected and the most likely explanation is contamination or a dodgy test strip. Alternatively see if the same thing happens on another day when you have the same routine..

 

[everydayupsanddowns]

Nothing is wrong, its just the nature of testing and the random errors that occur in manufacture of test strips

Yes I think that’s it exactly.

We can expect to be within 15% of a lab value of the same sample 95% of the time (and closer more often than that, especially at lower values). But strip manufacture / variation means that some strips may not perform at that level.

Here’s that handy table

 

[Docb]

@everydayupsanddowns - the table is useful because it gives some idea about the reproducibility of the testing system.

One point of interest is that at first sight there would be no reason to expect the error to be dependent on the value. I would expect the rough and ready procedure I got from the results of my 10 finger test - round to the nearest whole number and add an error bar of +/- 1 for ordinary purposes (0.67 confidence) or +/- 2 (0.95 confidence) - to apply across the range. It might be that the reproducibility goes off at the extremes but then alarm bells would be ringing anyway.

As I have said before, I would ban the use of percentages except by those who understood what was going on, especially politicians, journalists and people who write marketing guff leaflets.

PS My percentages ban would extend to those who write standards!

 

[Kayte]

My fingerpick test first thing this morning was 4.9. I didn't have breakfast and had a very low carb lunch of cheese and yogurt. Just did another test prior to evening meal and the reading is 8.8. How can it have gone up so much when I've eaten only around 15g of carbs so far, and walked just under 9,000 steps? Is it possible that I should have eaten more carbs? My evening meal will be more carb heavy

It's the fat that's caused it hun. Fat causes insulin resistance unfortunately, not carbs. Watch What the Health on Netflix which explains it all.