Dexcom G6 Sensor/Transmitter in Arm?

I have a copy of the 350 page Dexcom G6 User Manual (available free in PDF format on the Dexcom website and they’ll FedEx you a free copy if you fill out a form, also on the website)…

The manual states clearly that children can mount the sensor/transmitter on their bellies or buttocks. If you’re over 18 years of age, you can ONLY mount it on your belly according to the manual. Wherever you mount it, the User Manual specifies that the sensor/transmitter should be mounted horizontally, not vertically or on an angle.

Here in the forum, I see posts that people are mounting on their arm, which is in direct dispute with the instructions in the user manual. Why do people do this? Is there any advantages or disadvantages that people have see from mounting on their arm???

I use XDrip exclusively and get an average of 17 days per sensor when the sensor/transmitter is mounted on my belly in a horizontal position…

I use my abdomen for pump infusion sets, and prefer to not put dexcom there. Dexcom works fine for me on arms and inner thighs, vertically in both locations. Been doing that for over 10 years.

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I wear the dexcom g6 on my arm because I have fat there but not so much fat on abdomen.

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I use my arms, but I rotate with my hips. In general, I think I did too many shots, as a kid, in my arms, and so may have negatively impacted the absorption rates there. I get occasional POD failures there, but they are rare and I find that if I rotate, I rarely have issues. I find that I need to rotate over a greater area than just one spot. I really dont like it on my stomach…it negatively impacts my hourglass figure, lol.

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I’ve only ever worn mine on my arm. I switch arms every 10 days. Dexcom can only tell you what was specifically tested/approved. A couple times I’ve called Dexcom about a sensor issue they always ask where I had it and they never say anything about not putting it on my arm.

I think there are more locations that work and they know it, they just can’t say it because its not tested/approved.

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That is correct - Dexcom has been teased for years when they go to children’s diabetic camps and see 100% of the kids wearing sensor on their arm. Dexcom just did not use that placement for their initial approval so they can’t recommend it.

Since I have very low BMI, (18.5) I have asked several times if they were seeking approval for additional positions and they have mostly told me no but position can be anywhere agreed upon by you and your doctor.

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If you don’t mind sharing, do you use your arm for the sensor? I’m just wondering if arm works better than abdomen when one has a low BMI. Someone in another thread mentioned this.

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Hi Trying:

No I do not use arms for sensor as I sleep on my sides and am afraid that an arm position would result in frequent compression lows when transmitter gets buried in mattress.

For me the best positions are in a straight line between the belly button and xiphoid process. That way I can sleep on either right side or left side and transmitter still gets line of sight to receiver. There is enough real estate in that area to move the sensor up or down up to a couple of inches so that insertion areas get a a few weeks of rest before they are reused.

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Thank you for sharing! I’ve not thought to use this area. Will give it a try.

I have always used my arms, the libre recommends them there, so I was used to things being on my arms. I saw several videos of people putting them on their arms, so I figured why not?

I’m not sure why but I feel I have a little more versatility rotating my pod around my stomach without wondering where the dexcom has been too.

I’ve only had a problem with the sensor once not reading for a few hours and I always sleep on my sides.

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You mention keeping the transmitter in ‘line of sight’ to the receiver - can you explain why you think that is important? My son’s phone easily picks up the signal right through the mattress, floor and double-brick wall when he goes to bed and accidentally leaved his phone on the charger in the kitchen.
To the OP: FWIW my son mostly wears the sensors on his arm, but sometimes belly or upper buttocks. The arm seems to suffer from less lag between CGM and measured BGL than the upper buttock (along with higher and lower spikes. Both are similar in terms of compression lows (which are due to physical compression of the area the sensor is in, and nothing to do with obstruction of the bluetooth signal) but this would vary depending on your sleeping position (he rolls around a lot). The belly is our least preferred spot, it peels off the quickest and fails soonest because the skin moves the most. A tug on the sensor (which could be from leaning against a desk, contact sports or just skin folds moving when bending over or wriggling around) causes the filament to move under your skin, leading to a ‘sensor failure’ - sometimes these can come good if you wait a while and restart them, but if the filament has pulled out too much it is toast.

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We are all different and what works for one person does not necessarily work for another. I have a low BMI 18.5 and have read a lot of posts of individuals with low BMI having issues with Dexcom CGM readings. For me, line of sight is very important. I don’t even need much compression to cause a compression low, by wearing the sensor just above the belly button, all I need to do is turn onto my stomach on mattress and even with holding myself up with my arms so transmitter fully touches the mattress without compression, my BG drops about 50 points with receiver just 2 feet away on night table. If I snuggle a partner and just have transmitter touch skin of partner I get total signal loss.

There is an ongoing argument if it is a bluetooth signal issue or filament in fluid issue. In reality it is probably a combination of both depending on individual and situation and equipment. I am on Dexcom G5 and receiver. Even with Dexcom there are several variables such as if you are using a receiver or a phone, which app you are using if with a phone, which transmitter G4,G5, or G6 and if you are on blue tooth which BT version you have and which Dexcom version of software you are running. My mattress is memory foam and maybe that is even a contributor.

You are lucky that your son’s signal will go through mattress, floor, brick walls and leap tall buildings in a single bound. I am not so lucky so obviously what works or does not work for me does not affect your situation. You claim your son still gets compression lows from time to time. I keep line of sight for past 8 months and have not had 1 compression low.

Belly is best position for me and by using opsite, have never had a sensor pull out due to folding skin, sports, furniture, seat belts etc. and by keeping line of sight between transmitter and receiver never lose or distort signal when within 20 unobstructed feet between transmitter and receiver.

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From everything I’ve read about Dexcom, all the processing happens on the transmitter, and the app or receiver just displays the values calculated on the transmitter. The app or receiver (or pump) also let you enter a calibration value, and send sensor start/stop commands to the transmitter so it knows which inbuilt calibration curve to use (based on time since sensor start), but the processing still happens solely on the transmitter. Interrupting the Bluetooth signal shouldn’t be able to affect the values displayed, it’s a digital protocol with checksum so it (whether phone app or receiver) should either show the value sent by the transmitter or nothing at all.

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“should” is I think the caveat here. We all know that BT is suseptible to signal distortion. There is also a possibility of positioning of sensor filament in the interstitial fluid that could affect what the transmitter sends. There are two different scenarios. 1 is signal/no signal and I can make that easily happen even with transmitter within 2 ft of receiver. 2 is what I believe to be signal distortion from compression low. Once I start to roll onto my stomach inserted sensor, my BG drops 20 - 60 points, usually more in the 40-50 range. Again, I can easily make this happen by lightly rolling onto sensor and then comes right back to normal within 5 minutes when I roll back off sensor. Since I can deeply bury transmitter into mattress, or very lightly bury into mattress with same modified BG results, my assumption leans more toward BT signal distortion than change in filament position in fluid. I had fun a while back showing a roller coaster curve on my receiver by rolling on and off transmitter several times to show that it can be totally artificially induced.

I think it probably has a lot to do with that low BMI. Because I can have the reader in another room with a wall separating me and it still reads fine, as long as that other room is within 20-30 feet. I also lay on my arm where it’s and don’t have an issue. So it’s just not a line of site issue. Maybe with a low BMI there’s not as much area/fluid/tissue it’s reading from so any pressure disrupts it’s ability.

Ive been applying the last 3 sensors on my arm & getting readings. I was putting them on my stomach & was having issues with them falling off. I’m 65 yrs old & using the g6 for about 6 mos.

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I have been using Dexcom since November 2012. I wore my first sensor horizontally on my abdomen but it was uncomfortable and the readings were never very accurate. I posed the question to one of my D groups and the overwhelming answer was the ONLY reason the manual states to wear the sensor horizontally on the abdomen was because that was the ONLY site Dexcom applied for FDA approval. If Dexcom had ponied up the $ to have other sites approved the FDA would have approved it. In fact Dexcom was forced to seek buttocks site approval by unhappy parents. I’ve worn a sensor on my shoulder blade, ankle, thigh, forearm, back of arm and calf. My longest worn sensor was 53 days (yes I know the manual says to start a new one at 7 or now at 10 days). I rarely have sensor failures but when I do call them in to Dexcom I am always up front with them about sensor placement. I also say that my endo recommends I use a site that is comfortable and accurate. So far in 6+ years I have never been denied a replacement.

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I put one on horizontally the other day…just to see what happened. It fell out. It hurt. Not a large enough surface area on my arm.

I wear them vertically on my arm. Vertically works great. It seems like horizontal on the arm wouldn’t work well.

Okay, I’m 55 years into T1 and current G6 user…what is the xiphoid process?