Dexcom G4 vs. Medtronic Enlite: The Low Down

There are many tools in my diabetes arsenal which help me smash diabetes out of the park and continue living my life the way I want.  But there are two above all others to which I credit my current success: Continuous Glucose Monitoring (CGM) and my insulin pump, Lord Pumpington.

CGM has been around now for around a decade and gives us the tools to monitor glucose levels within the tissue beneath the skin, feeding back results around every five minutes with a lag time of between five and 15 minutes.  When I was first diagnosed in 1986, we had to pee on sticks to find out what our bloods were doing four hours ago (useful, maybe, as long as you don't have diabetes mind....).

If you are considering Continuous Glucose Monitoring, you probably have one major question rolling around your brain: which system is best for me?  There are two available in the UK; the Medtronic Enlite and the Dexcom G4.  I had the opportunity to try both systems and know that when deciding, it wasn't the gumph (actual term) spouted by the pharma companies but the experiences of others with T1D which led me to my final decision. So here it is, my breakdown of the major differences/benefits of both systems.

Insertion

For this one, Medtronic win hands down.  The Enlites benefit from an automatic inserter in which the sensor sits and from which it is discharged into the skin at the touch of the button.  This means you don't even need to see the needle, let alone insert or retrieve it.  

Comfort

This one is firmly in camp Dexcom.  When you insert your first sensor and have it camped out on your abdominal landscape you will think of nothing else, for a while.  Eventually however, the sensor will become as much a part of you as the watch on your wrist: you know it's there but it comfortably fits in your life, serving a purpose and earning its place on your person.  When I tried the Enlites even after five weeks and having grown used to having CGM in my life, the sensor adhesion felt 'fragile' on me - as though one good knock would see the sensor come away and £50 down the drain.  The Dexcom however feels 'bomb-proof'.  I have bashed it on walls,  scratched at it, got it caught on clothes and been through many a vigorous gym workout.  Nada. That bad boy stays put

Cost

This is the real nitty gritty and, if we're honest, a major factor if you are thinking of bringing CGM into your life.  It is a long term tool, meaning long term costs.  The options for buying include either purchasing a separate handheld unit (if you don't have a pump which can integrate CGM), or buying the kit which integrates into a pump.  I've included the actual costs on the chart below but again, the Dexcom G4 is the industry's worst-kept secret for lasting far longer than the manufacturer's recommendations, making it the much more affordable system

Insulin Pump integration

Both Dexcom and Enlite can be integrated into pumps so this one would be an even keel.  This means the results are sent wirelessly to the pump screen and are 'with you' at all times.

The Dexcom G4 can be integrated into the Animas Vibe insulin pump and the Medtronic Enlites can be integrated with the Medtronic Paradigm Veo.

The Vibe is a waterproof insulin pump which may be worth considering if you are an active water-baby.

The Paradigm Veo on the other-hand has a feature called 'low-glucose suspend', meaning if glucose levels reach a certain low-point, the pump will suspend until glucose levels rise.  Useful if you have kids or severe night-time hypoglycaemia unawareness.

For that reason, there is no winner here, just different selling point.

Low Glucose Suspend

This is perhaps the greatest feature of the Veo and certainly a consideration between the two systems.  I don't suffer severe hypos; but many do.  The Medtronic Enlite system is the only system currently on the market which has the capability to suspend the pump temporarily (up to 2 hours unless someone interacts with the pump, in which case in turns back on immediately) for the purpose of stopping a hypo from progressing further.  This means the Medtronic is the clear winner in this category

Length of wear

One of the biggest factors in making my final decision on which system I should chose was based on the diabetes community's worst-kept secret; that the Dexcom can be 'tricked' into working for far longer than the seven days it has CE approval for.  I'd heard rumours that people could get up to three weeks or so out of the new fourth generation sensors.  And it has most certainly lived up to expectations.  My shortest sensor lasted eight days; My longest, an impressive 36!  Other than that, each sensor I have used has lasted between 14 and 36 days, with the last four alone going between 22 and 36 days. I've heard of one person getting 12 days out of an Enlite sensor but personally after five weeks trial, I never managed more than 8 days.  Meaning the cost really was £50 per week.  Dexcom wins.

Overall Experience

There is a reason I wear a Dexcom, and not a Medtronic Enlite.  There are numerous reasons, in fact.  Even though I use a Paradigm Veo insulin pump (for now) and could have integrated the CGM much cheaper than by forking out for the stand alone kit, it was the accuracy, length of wear, comfort and overall experience of the Dexcom that made it the system I chose.  Everything the Enlites lacked for me, the Dexcom could offer. While there may be considerations such as the false high readings from paracetamol (personally I just switched to Ibuprofen.  Problem solved), the benefits of CGM - and more specifically, the Dexcom G4/Animas Vibe insulin pump system - mean it was a clear choice for me after having tried them both.  

And the benefits CGM has brought to my life are 100-fold:  No more overnight testing, fewer night -time hypos and continuous results driving my decisions, making working, driving, exercising and living my life, easier.  The improvements in my glucose readings are even so marked that I'm even looking forward to my next HbA1c, confident that it will be my best yet.  And for anyone's who been reading this blog a while you will know those are big words, coming from me.

Here it is, the run-down I hope you find useful:

	Dexcom G4	Medtronic Enlite
Cost	£46.50 per sensor £450 starter kit (for integrated pump.  Four sensors included) £975 for stand alone unit (for those without integration feature on pump)	£52 per sensor £750 for starter kit (for integrated pump.  10 Sensors included) Unknown cost for stand alone unit.
Calibrations needed	2 per day although more results can be entered	2 per day.  No more than 4.
Length of wear (according to manufacturer’s guidance)	7 days (CE approved)	6 days (CE approved)
Actual wear by customer’s choice (not advised)	Personal experience of between eight and 36 days wear before sensors expired	Personal experience of only 8 days before sensors expired
Comfort	Extremely comfortable.  Longest time worn for 36 days ith no irritation and very small entry hole. Extremely secure when in place	Comfortable. Longest worn for 8 days, but aware of the sensor site at this time and reasonably irritated on removal. Not as secure feeling when in place
Integrated into pump	Yes, only with Animas Vibe	Yes, only with Medtronic Paradigm Veo
Low Glucose suspend (safety feature to suspend pump temporarily when hypo)	No	Yes, when integrated with Paradigm Veo pump
Alarms	Very good.  Audible, simple, easy to amend upper and lower limits	Good but less audible when pump under covers.  Somewhat over sensitive (alarms when changing very slightly).
Paracetamol use while wearing sensor?	No. It interacts with the fluid giving a false high	Yes.  No issue with fluid interaction.
Range	20 ft, can work between rooms (with stand alone unit)	6 ft (with standalone unit)
Accuracy (MARD score – the gold standard of glucose testing. The lower the MARD, the more accurate the device is considered)	14%	15.3%