Since I test my BG so infrequently now because of my Dexcom for calibrating I sometimes test my BG twice in a row. I have noticed that my left hand is always about 20-30 points higher than my right hand. I attributed this to simple BG meter variance. But several times I have tested a third time on the initial hand and those numbers match up.
Why is my left hand always higher? But more importantly, should we be always calibrating our CGMs from the same hand/location?
I have the same only my left hand is alway lower than the right hand. I always test twice - both right and left hand - when calibrating and if the resulst differ I use the mean value.
Just like @Siri, I test right and then left (same finger respectively) for calibrations. When I get a wild number that doesn’t match my expectations, I move to the other hand.
I find that sometimes they are significantly different. I attribute the difference to having used one hand more than the other, or sleeping on one side, etc. I am relatively ambidextrous, but if you are really dominant on one side, you might expect some BG differences.
can’t say I see a difference, but I’ve read (years ago) that the more your bg’s are fluctuating, the more likely that you will have a discrepancy between left and right. I’ve no idea if that’s correct, so if curious do some experimenting.
since i first read your post, i began testing on both L & R fingers before meals. yesterday, i had a very wide discrepancy. 135 on the right hand and 158 on the left hand. i used the mean # to calibrate the difference, and i put it in my pump as well before blousing for my meal. its an interesting question why this occurs. i have also found that even when testing on the same hand but diff fingers, i have similar experiences.
to see if you meter is “flaky” or not, get a LARGE drop of blood and put some of the blood from that drop on 2 consecutive strips to see if the meter is giving consistent readings from the same drop of blood. If the readings differ it’s not the source of the blood that is the issue–its your meter.
thanks. i will try this for lunch.
This is around a 17% difference which, if I am recalling correctly, is within the 20% tolerance required of BG meters. (Yes?)
So … why was there a difference? Was there actually a difference in the amount of Blood Glucose (BG) between your two hands? Was it the result of a possible contamination on one or both hands? Was it the result of “error” in the BG meter? Was it possibly some combination of some or all of these factors?
While the truth may indeed be “out there”, it can often be a squiggly little bugger which is harder to catch than we often assume.
i have been reluctant to change meters over the years. i love my meter (one touch soft touch) but i think that it is time that i moved upwards. my battery is fine, and i do get proper readings, but since i read the site about having diff #s on diff hands on diff fingers, i did some experimenting. some times the 2 #s are dead on, this afternoon this was not the case.
I recently switched to the one touch verio and have noticed it to be more accurate and more in line with my Dexcom readings.
what concerns me about this issue is that i don’t plan on testing on diff fingers before every meal. now, since i have noticed the discrepancies in BG readings, i am curious if i am telling my pump to over bolus me or under bolus me. and, how will that make a diff in my reaction of my meal carbs and my future BGs?
That would really depend a lot on how sensitive you are to insulin and just how high your “carb ratio” might be. If it takes very little insulin to drop your BG or to take care of the carbs you eat, then it might be more of a problem.
Personally, I find my insulin sensitivity can vary depending on my activity level and probably other things I’m not even aware of. Although the models we are encouraged to follow treat your glucose versus insulin balance as just a mechanical process, it actually can be far from that in my experience.
My attitude is use the models but expect and try to be prepared for the unexpected. And if the “unexpected” starts happening regularly, then consider re-balancing your pump settings.
I’ve use countless meters. over the full range that my bg’s have covered (38-260) over the years, my opinion is that the most accurate meters are the verio and the Contour Next. The accucheck compact plus reads too high as the actual values begin to climb above the upper 100’s. That used to mess me up. You name it, I’ve used it. all sorts of brands and models.
Well, are you going too high or too low? there’s your answer. You have to be using the correct I:C ratio and need an accurate meter, of course.
I would like to dispel the myth that Dexcom readings being in line with BG meter readings imply that the BG meter is accurate. Assume you have a watch and a wall clock. You set the wall clock to the time that is on your watch. Now both show the same time going forward. Does this mean that your watch shows the correct time? Not really.
If you are referring to the roughly 15 minute time-difference between ISF results, vs finger sticks, I agree. Otherwise, I’m not sure what point you are making.
My PDM reads low more than 20% when I use code 16. Let’s assume my BG is 100. My PDM would say it is 80. If I calibrate my dex with this value then the dex will show 80 too. Now both PDM and dex show 80. What I am saying is that both PDM and dex showing 80 does not make my BG 80 and does not mean that the PDM is accurrate. My BG is 100. The dex readings are not independent. The dex agreeing with the PDM that was used to calibrate the dex does not mean anything.
aren’t you making an argument, using a limited set of circumstances? I don’t see the point.
I should have quoted Anthony’s post which compelled me to post. The only way to assess the accuracy of a BG meter is to compare it to something that is accurate. Comparing a BG meter to the dex makes no sense at all.
Phoenixbound:
after multiple BG testing w/ my favorite but very ancient meter, i finally started using a newer model. w/ the old model, i tested on more than several occasions 3-4 times each. i was changing hands, fingers, lancets, etc ; i was getting very different results from each consecutive test. the range was simply too great for my meter to be behaving accurately. also, once i tested out the newer meter, it really jibed with my BG#s on my cgm. w/out saying, this change made me feel more comfortable. and i understand you when you mentioned that my pump can only account for the info i put into it. i am hoping that now my input “matches” more accurately the proper insulin needs. ( i use the Wizard function most of the time as it accounts for IOB and i am too lazy to be either a chemist or a mathematics expert)
needless to say, i appreciate your sage advice. hopefully this new meter will behave more angelic.