Nocturnal hypo unawareness and driving

[Rnr1975]

i have recently started on a libre and it has thrown up that I have been having night time hypos that I am unaware of. Should I let the DVLA know as when awake I am fully aware of them mostly between 3.5 and 4

 

[novorapidboi26]

No...

Well, if you think you cant recognize when your awake then yes....

but during sleep you can sleep through mild lows.....what was the level?....

the DVLA should only be made aware of hypos requiring third party intervention....

 

[Rnr1975]

Might times were above 3 but it also explains the feeling like I have never slept before as well, on nights where I am not hypo am also having massive DP such a nightmare

 

[EllsKBells]

Also important to bear in mind that the libre is not 100% accurate, and may vary slightly compared to capillary testing. Personally I find that when i am close to a hypo, low 4s say, the libre tends to get a bit 'overexcited' and may claim that I am 3. something, which will then be revealed by a blood test to be 4 point something.

 

[Rnr1975]

Lol sorry but when there is an allowable variance of 4.0 mmols in meters who is to say which is correct

 

[tim2000s]

Lol sorry but when there is an allowable variance of 4.0 mmols in meters who is to say which is correct

No. there isn't. There is an allowable variation of 95% of results must fall :

• Within ± 0.83 mmol/L of laboratory results at concentrations of under 5.6 mmol/l
• Within ± 15% of laboratory results at concentrations of 5.6 mmol/L (100 mg/dL) or more

 

[Rnr1975]

Sorry Tim but that is still a possible variance of 1.5 mmols ish, all I was trying to say is there is a big allowable difference, thus who is to say which is correct?

 

[tim2000s]

Sorry Tim but that is still a possible variance of 1.5 mmols ish, all I was trying to say is there is a big allowable difference, thus who is to say which is correct?

Once again, no. The possible variance isn't 1.5 mmol/l. The possible range is 1.5 mmol/l, distributed on a normal curve. A test will not be 1.5 mmol/l away from the real value, it will be no more than 0.83 away from the real value, 95% of the time , which is a significantly different statement.

As per the image below, the range of values at 4 mmol/l, 95% of the time, lies between the two red lines on the curve. Or to put it another way, the maximum variance is 0.83mmol/l in either direction, but the value on the meter is much more likely to be around about the real value than at the extremes we always talk about.

 

[slip]

Are you sure your night time hypos aren't compression lows?

 

[Rnr1975]

Compression lows??

 

[slip]

Compression lows??

Laying on the sensor can have an affect on it's results, think of the area under the sensor as a sponge, the fluid the sensor uses to measure your 'blood glucose' level is free to move around inbetween the cells, squash that area, like pressing on a sponge it squeezes out the fluid, reducing the fluid the sensor has to sense and measure on - affecting it's calculations.

The only way to tell if you are getting false hypos, is to test at the time, but as you're sound a sleep.......so you could set an alarm and hope that coincides with a 'low' or buy 2 readers and wear 2 sensors on different arms! (you could work out how many times you turn over in the night then too!! LOL)

 

[Margie@home]

I use a Libre with the sensor and find there is sometimes a difference between the blood test and the sensor. My doctor said there is a gap of 20 mins between the levels. It is interesting to note how levels go up even if you have not eaten for several hours.
It is expensive to buy but I think it would be cheaper for the NHS to supply them as it saves on the cost of blood strips and lancets and means testing can be done anywhere an as many times as you want.
I get better control now.
Margie@home

 

[slip]

It is interesting to note how levels go up even if you have not eaten for several hours.

That could indicate your basal amount isn't quite right - there are lots and if and buts but if your BS always creeps up when not eating you may want to do a 'basal test' - there will be a link somewhere on the forum for how to do a basal test so do a search.

 

[Engineer88]

tell the DVLA if you want to lose your license because that's the only thing which will happen.

 

[Deleted Account]

If you are treating your diabetes with insulin, you must tell the DVLA. They will ask if you have experienced an "episode of severe hypoglycaemia". They seem vague about what this means but I have read that it is usually interpreted as a hypo that has been so severe that you have not been able to treat it yourself.
A reported reading of between 3.5 and 4.0 is unlikely to be considered "severe".