Disappearing trend arrow?

has anyone else had their trend arrows disappear for long periods of time? i ate a meal about an hour ago, and i know my blood sugar is still rising from that and has been ever since i ate, but there are no trend arrows showing upward movement. my blood sugar reading keeps updating every five minutes and each one is higher than the last, but no arrows…any suggestions?

I have seen the trend arrow on my monitor disappear for short periods, say 10 minutes or less, but I’ve never seen it disappear for longer than that. Does this occur after the first sensor day? I wonder what explanation the help line would give.

I’ve learned that the “sideways arrow” can actually indicate a slow rise or a slow fall. I’d like to see an arrow that indicates true sideways (or very slow rise or fall) movement.

Hi, Lindsay.

If you’re meaning that there is still a LEVEL arrow, then check the rate on the graph-- Dexcom won’t show a trend of less than 1 mg/dL. This means you need to be changing by at least 15 mg/dL, across only 3 readings, for Dexcom to abandon the “level” arrow.

But if it’s really as you say, with your monitor/receiver not showing any arrow AT ALL, then I think it’s broken: mine always shows at least one of the five kinds of arrows, unless it’s gone “???” too.

Mine sometimes shows no arrow as well. I don’t have any good reason for it and have never had reason to believe my sugars weren’t stable so I wasn’t worried about it. But if it’s not normal I’d like to know that!

i want to call the support line and ask about it, but it doesn’t strike me as particularly urgent, so i guess it will wait till monday morning. i’ll definitely post their response on this board for any interested parties.

as for your questions, terry, i’m partway into my second day on this sensor, and the trend arrow has been absent for longer than ten minutes at a time off and on all day. what confuses the matter is that it SOMETIMES shows an arrow, and sometimes not. and it still shows a level arrow sometimes, so it’s not just a matter of the lack of arrow representing a plateau, especially since it has been absent during some pretty major rises and falls. for example, just a couple of hours ago i dropped from 162 to 55 in less than half an hour and the receiver showed no arrows, just blood sugar readings (and no ???). i had no idea i was dropping that fast and if i hadn’t been watching the graph like a hawk (really just on a whim), i wouldn’t have caught the low and begun treatment as soon as i did.

So, now that I’m actually watching it, my arrow has been missing for the last hour but the graph has gone up and down as food and insulin have been waring. Please let me know what Dexcom says about our missing trend arrows!


Anyway, I don’t recall a vanishing arrow on the standard display-- but my memory isn’t very good for these things and I’ll be sure to but I’ll be sure come back and see your report on this after I get back from a short trip. Did you at least get the “LOW!” alarm buzzer+vibrate event?

I keep mine set pretty high assure that lows always get caught. The trade off is of course, that I do here several alarms per day. My setting is 80 mg/dL most of time, but I raise that to 90 or even 100 when I’ve got lots of “adjustment” insulin on board, or other risky behavior in progress. It takes only a few clicks to change the alarm, and for me, changing the “low” alarm setting has become became as routine as entering finger-pokes for calibration.

I would call the help line right away. Dropping from 162 to 55 without any trend arrow is cause for concern. Did you get a low blood glucose alarm at 80 (or whatever level you set for the low threshold)?

If I understand correctly, the graph is plotted with a data point BG level every five minutes but the trend arrow is missing. If that’s true then at least you have the visual cue of the falling plot-line.

The presence of the trend arrow is a major visual cue that we all depend on. Dexcom promotes that feature as it markets its CGM. It’s absence raises the question: What else might be wrong with your system?

I wouldn’t feel the need to delay your question until normal business hours but would call right away. If your receiver or transmitter is defective or questionable you can get this situation resolved and addressed sooner.

Good luck. In any case, I will look for your update to see what Dexcom thinks is going on.

so i called dexcom a few minutes ago and was pretty frustrated/disappointed with the woman i spoke to. she told me it isn’t normal for a trend arrow to disappear (well no kidding!) but that there’s probably nothing wrong and that maybe my blood sugar wasn’t changing that quickly.

i explained to her that i had a massive crash from the mid 100’s to 55 in a very short time, and that i also have experienced the lack of trend arrow when i was rising very rapidly and my sensor never gave ??? or inconsistent (i.e. rapid up and down) readings. her response is that she can’t tell me anything until i can upload my readings to a computer and send her the information so she can see “what the receiver was doing at that time.” unfortunately, i am a mac user and am working on getting my hands on a copy of windows so i can use the software that comes with the dex. but in the meantime, i can’t upload the information and i can’t send her anything so she essentially told me that i’m out of luck till i can do that and there’s nothing she can do.

maybe if you call, Rebecca, and send them your numbers from the days/times when the arrow is missing they will be able to troubleshoot with you? for the time being i am supposed to keep them posted if it disappears again and call back once i have the software installed…grrr…

That was a frustrating and disappointing response! I would have expected that they have heard of this situation before and would have already developed a reasonable response.

I have a Mac too and I wanted to use the data management software for my own education. I also wanted to be able to print out one week’s charts to show my doctor when I go for a visit.

I didn’t want to install Windows onto my Mac so I bought a small “netbook” computer. It’s a small laptop and I paid under $400 for it. I know there are models for less than $300. I now view all my blood sugar data on this netbook. It’s working well and I think its a good investment in my health.

Whether you use your Mac or get a small netbook, I think that you may discover more value looking at the charts and graphs on a computer screen than limiting your view to the small screen on the receiver. Looking at a whole day’s data gives better perspective and will allow you to spot trends more easily and enable better analysis.

The data management software can display averages for every hour of the day for say, one month. It can also take one day and graphically show the percentage of readings within various BG ranges: 39-55, 56-70, 71-100, 101-130, 131-160, 161-190, 191-200, etc.

It’s interesting to note the average BG for a one month or 90 period. It also gives the standard deviation (a measure of BG variability). I’m interested in this measure because the A1c that my doctor looks at does not reveal if I’ve been swinging high and low.

Good luck setting up your computer. It’s been worth it for me.

Next time I notice the arrow is gone I will make record of when I notice it and when it comes back, download the info from my receiver and call them. I hesitate to use the info from yesterday as that sensor failed on me last night and I fear they will blame it on the sensor even though I know I’ve seen it before. But next time I see it I’ll definitely record it and call them. Thanks for bringing up the problem and trying to get an answer. I’ll see what I can do now.

let me know if you ever get any more answers out of them. i’ll keep trying from my end (which will be much more feasible once i get the software installed) and i’ll keep you posted on any developments!

thanks for the advice, terry! i think i’m going to try to use bootcamp on my mac to partition the disk so i can run windows as well as os x. my problem is that i’m a poor graduate student so i’m looking for cheap/free copies of windows before i shell out the $200 that it would cost for vista.

You can run Windows 7 for free on your mac for a year. Google it.

Terry, I totally agree that the software brings a lot of value to the table. My favorite graph is the ‘Glucose Distribution’. For a CGM user A1C only serves as a sanity check. Otherwise it is totally useless. I look at the Glucose Distribution to find out how I am doing. I also notice a lot of self-fulfilling prophecy. For example, at one point I measured my success by how much time I spent above 130. In the following weeks my time spent above 130 came down. Then I realized that normal people ‘live’ between 71-100 most of the time. In the following weeks the 71-100 bar became my highest bar. I have an addictive personality and can get sucked into any challenge. I like the challenge of improving my bg control because the insurance pays for the toy (CGM) and all I can see is upside. I could not feel as good about myself if I invested the same effort into a video game.

Helmut – I think I share with you an enjoyment of looking at the data. Some people may think this type of careful observation as “obsessive” but I don’t see it that way when you consider what the stakes are when diabetes is poorly controlled for long periods.

I strongly agree that whatever numbers you follow closely will tend to be the numbers that improve. My overall numbers have improved a lot. I spend much less time in hyperglycemia (<240) and the time below 60 is also greatly diminished. I don’t have the control that you exert on yourself but I see things improving by leaps and bounds.

When I see my endo in a few days I expect my A1c to be under 7% for the first time in about 2 1/2 years. While I agree that the A1c is a very course measure of the quality of glucose control, it was cited as a key threshold in the diabetes complications and control trial that was published over 10 years ago.

By the way, I suspect that my body starts to put the “metabolic brakes” on (liver releases its sugar) when I drop below 80. I have watched many times as my BG sunk to the mid to low 70s and I treat with 4 or 8 grams of glucose and the BG over-responds by rising to 140-150. I’m not certain of this conclusion, it’s a hunch I have though.

I have great hopes for the Dexcom in improving my health and I don’t consider a system without the data management program a complete one.

Terry, I didn’t mean to say that average (=A1C) is not important. Studies have shown that average and variability are independent risk factors. Glancing at the glucose distribution I can see both and the graphical presentation appeals to me. I tried to simplify and look at average and standard deviation only. The reason being that numbers are easier to compare than graphs. Whenever I just looked at average and standard deviation I felt the strong urge to look at the glucose distribution to see whole story. In the meantime I know what a good graph looks like for me. I purposely try to stay away from making my A1C number better because the easy solution is hard to resist: lows.

I am glad that I found a fellow in you who also enjoys looking at data. Let me know when you find something new or interesting.

I don’t think they’re giving out RC product keys any more… since the actual product release is coming up very soon.

That said, I am running Windows 7 in VMWare Fusion… it works great :slight_smile:

I wish I wouldn’t need a cable to offload my 7+. This would be the trigger to install Windows 7 on my mac. The cable is with the pc in the basement. Even better, I want to see the glucose distribution, average and standard deviation on the receiver. Then there would be no reason to ever hook up the thingy to a computer. Maybe this will come with the OmniPod integration. I hope I will get approved for the OmniPod.

I realize this is a really old thread, but I’m posting here in case anyone knows anything more about it. I just started my Dexcom yesterday (hooray for completely spending my savings!). It’s been working fine, except for the last 45 minutes, there hasn’t been any arrow. I haven’t changed that much - just 130 to 119, but there haven’t been any arrows at all, no sideways arrow, no up arrow, no down arrow. I keep hitting refresh to see if it will pop up, but it hasn’t yet.

Does anyone know anything about why this happens or how to fix it?