Review of the FreeStyle Libre System
The main headline on the Abbot website and their literature states and I quote:
FreeStyle Libre Flash
Glucose Monitoring System
The days of routine glucose testing with lancets, test strips and blood are over.1
Welcome to flash glucose monitoring!
The small print says and I quote:
1. A finger prick test using a blood glucose meter is required during times of rapidly changing glucose levels when interstitial fluid glucose levels may not accurately reflect blood glucose levels, or if hypoglycaemia or impending hypoglycaemia is reported or the symptoms do not match the system readings.
True or not?
I self-funded the FreeStyle Libre system from November 2016 until June 2018. I no longer need it because I now use a Medtronic 640g insulin pump with continuous glucose monitor, which is funded through the Irish Long Term Illness Scheme.
Libre is a continuous glucose monitor (CGM) which measures glucose in extracellular (cell) fluid which surrounds all cells in the body. Glucose comes from food that we eat and some is secreted by the liver. Lots of things contribute to blood glucose levels, but that is a discussion for another day. Our body digests food by mixing it with acids and enzymes in the stomach. The digestive process breaks down food containing carbohydrate (starch and sugar) into glucose. The stomach and small intestine absorb the glucose and release it into the bloodstream. It is at this point that blood glucose tests are performed using conventional meters for personal use by people with diabetes. From there glucose is distributed through cell fluid to the parts of the body that need it for energy. It is at this point that FreeStyle Libre measures glucose.
Plus points:
√ Ordering was quick & easy. I logged onto the Abbot website and ordered a starter kit which cost €175. This consisted of 1 reader device and 2 sensors (each sensor lasts for 14 days). The reader is similar in size and shape and doubles up as a blood glucose test meter.
√ The kit arrived, well packaged and undamaged, in 4 working days.
√ It was easy to get started. In addition to the instruction booklet, there was an A3 sheet with clear diagrams that made it easy to set up the sensor. The applicator is well designed and ensures that the sensor is securely attached.
√ The sensor was easy to attach to my arm, but did cause a bit of discomfort for a few minutes after it was applied.
√ Sensors are water-resistant in up to 1 meter (3 feet) of water for a maximum of 30 minutes, so showering is fine. I pat the sensor and the surrounding area to ensure it is dry after showering.
√ The backlight on the reader is great for night time use. Many manual test meters have backlights, but I have to turn on the light to use them, so wide awake by the time I have completed a test. With Libre, I just reach for it, press the ‘on’ button and scan my arm and my reading is there.
√ Best of all, I have found Libre scans match my blood glucose most of the time. I have had a few discrepancies. This does not mean that Libre is ‘wrong’. It just means that either the glucose in my blood (we all need some glucose in our blood at all times) hasn’t reached my cell fluid yet or my glucose level is changing too quickly for Libre to keep up.
Libre does not suit everyone with T1. Some people find that discrepancies between blood tests and Libre are too large for them.
√ Since I started using Libre I have completely dispensed with setting an alarm for 3am to check if my basal (background) insulin dose is correct. I used to do this every 2 weeks and more often if I had issues I thought were due to my basal dose. Bliss!
√ The arrow beside the number tells me if my cell glucose is going up, down or stable. This is a big bonus.
√ The sensor takes a reading every 15 minutes, whether it is scanned or not. I can see 8 hours of data at a time. It is fascinating to see the data, even if I have had crazy readings like on the graph below. I used to graph blood glucose tests using Excel, but I would have had to do finger prick tests every 15 minutes to get this amount of data.
√ I can add notes on insulin dosage, exercise, food etc. I don’t use this regularly, but it is a handy feature.
√ It is possible to set reminders to check glucose in 15 or more minutes. Handy when low. I have a daily alarm set to remind me to take my background insulin.
√ The software provided allows for a wide range of reports to be viewed on a PC or printed off. My Endocrinologist accepts these in place of the excel sheets I used before.
√ The reader doubles as a blood glucose meter.
√ Being able to scan anywhere is a huge gain…..on the street, while out walking, in the cinema, at night.
Not so good:
↓ While Libre is provided free to insulin-dependent diabetics in many countries, it is not in Ireland. FreeStyle Libre is being considered for inclusion in the Long-Term Illness scheme by the Health Service Executive in Ireland.
↓ The Libre system is too expensive for many people to use. The start-up cost is €175. After that, it costs €125.75 for 2 sensors, which last 4 weeks.
↓ The main headline on the Libre website says that the days of finger pricking are over for people who use Libre. Driving or operating dangerous machinery are not mentioned, even in the fine print. This is a misleading because blood testing is still required, particularly before driving for safety reasons and to comply with driving regulations in most countries. If I had an accident and I have my Libre reader with me which showed that I only performed a scan and not a finger prick blood test I may not be covered by my insurance and I have broken the law. I haven’t heard of any cases but I don’t want to be the test case.
↓ Abbot customer care representatives were pleasant when I was speaking to them, but it took several phone calls and emails to sort out missing deliveries and short expiry dates.
↓ This review isn’t a comparison to other continuous monitors, so I am overstepping the mark here……Libre does not have an alarm for low glucose readings. For true peace of mind, especially at night, an alarmed CGM, like Dexcom is the best, but is much more expensive than Libre, for anyone who has to self fund.
↓ There is quite a small area of adhesive around the sensor and if it is applied to the outer arm it is easy to catch it in doorways, etc.; they fall off and can’t be reapplied. They are too expensive to lose……….for added security, I cover mine with a plaster. There are fancy covers to overlay the sensor with, which are manufactured by varies companies, unrelated to Abbot but they are expensive and have to be ordered online. I use ones from IKEA, which I find great. Each pack contains 14 plasters which are an ideal size for over the sensors. The adhesive suits me better than other branded plasters.
↓ While I haven’t had major differences between scans and blood tests, there are differences, particularly if glucose is falling or rising quickly, or when I am sick, so I can’t depend 100% on it.
Conclusion:
I now use the Libre reader as my main method of checking blood glucose as well as scanning. I used to use different meters, but now Libre never leaves my side. The drop of blood shows that the 6.2 reading on the screen below was a blood test. The arrows beside the 6.1 and 6.2 readings tell me that these were scans.
I use a One Touch Verio, FreeStyle Optium Neo and Accu-Chek Aviva Expert to cross check. I nearly drove myself mad for the first few months, cross-checking Libre scans with blood tests using other meters. Thankfully, I rarely cross check now.
I often try to scan the arm that has no sensor!
Libre is not perfect and I don’t rely on it completely. I still perform finger blood tests before driving, before giving extra correction insulin, if I feel different than what the reader is telling me and lots of other times but I have to say it has made glucose monitoring much easier.
The days of routine glucose testing with lancets, test strips and blood are not over, but definitely reduced!
