I have lived with type 1 diabetes since 2002. The last year has seen a technological transformation in both measurable outcomes and quality of life. I’m not cured, but this is the next best thing for now.
The core tools I use to control the condition haven’t changed. I have a conventional insulin pump funded by the NHS—the Dana RS. I self-fund the Dexcom G6 continuous glucose monitoring system (CGM).
The life-changing shift was my decision to connect those two devices: to allow a mobile phone app to take control of my pump and to adjust insulin dosing in response to blood glucose data (Fig. 1a). The components form a closed loop system—sometimes known as an artificial pancreas. Users like me (‘loopers’) call it ‘looping’.
Without a fully functioning pancreas, it’s hard to match active insulin to the body’s changing needs. That’s why diabetes is tough—and it’s why most of us don’t meet healthcare targets. An insulin pump gives greater flexibility, but it doesn’t make the problem go away.
Looping changes that by predicting the future. If my blood glucose is falling, or if the system calculates that I’m going to become hypoglycaemic, it can reduce the supply of insulin in advance. If my blood glucose is rising, it can deliver more insulin—within strictly defined safety constraints. It’s like a sliding scale where you rethink the dose every 5 min.
Should I give a correction bolus? Should I change my basal rate? How can I reverse that trend? I used to invest lots of energy in answering questions like these. Now, the app handles them on my behalf. It’s not perfect, but it does a much better job than me.
Before looping, my HbA1c was around 57 mmol/mol. I worked hard to bring it down, but failed, year after year. In June 2018 I handed over control to the artificial pancreas, and by August my HbA1c had fallen to 45 mmol/mol. By January 2019 it was 43 mmol/mol (Fig. 1b). I typically spend 85–90% of the day between 4 and 10 mmol/L. The positive mental impact has been profound: I spend significantly less time managing diabetes, with improved results.
The system I use—AndroidAPS—is free to anyone with access to the Internet. Whilst the system is freely available, there are barriers. You need CGM and a compatible Bluetooth-enabled pump. You need to build and configure an app on an Android device. Even when you can see the potential benefits, it’s easy to feel discouraged by technology. The good news is that you don’t need to be a computer expert—and that the online community of loopers wants new users to succeed.
The features of AndroidAPS go beyond any commercial offering, and it is open-source: designed, maintained, supported and given away by a global community of volunteers. Nobody makes money from it or from two other similar systems, OpenAPS and Loop. No regulator has approved them either. This is the cutting edge of patient-led healthcare innovation, driven by people who don’t want to wait for the medical device industry to deliver the next generation of technology. Search online for #WeAreNotWaiting to learn more about this approach.
Is it risky? I have no adverse events to report. There may be unknown risks that come with DIY technology, but for me, looping reduces risk by improving both short- and long-term glycaemic control.
I realise that I am privileged, and part of my good luck is that I attend a great clinical service. I needed a specific pump to make looping possible, so access to that critical part of the system depended on my diabetes team. I explained what I wanted to do, why I believed it was right for me, and that I was not asking them to take responsibility for an unlicensed system. It took some negotiation, but they were interested and respectful from the start, and they did not erect unnecessary barriers.
That positive attitude extended to a recent hospital admission and cholecystectomy. The loop stayed active on the ward whilst I was too ill to care for myself, and the anaesthetist took the view that it was safe to let the system look after my blood glucose during surgery. I am convinced that AndroidAPS can take some of the credit for my fast recovery, and I am extremely grateful to everyone at the hospital for their willingness to accept my choices.
Loopers are still a tiny minority, but the number is growing. I believe that when patients choose to manage a condition like diabetes in ways that challenge the norm, we start to break down barriers. That can help to move healthcare technology forward for everyone.
In April 2017, our 11-month-old son was diagnosed with T1D at University College London Hospitals NHS Foundation Trust (UCLH). As our child was so young, we were fully funded to have a pump, Medtronic 640G, and the Enlite CGM sensors. Within the first week of diagnosis we had training on the pump, sensor and general management including carb counting. My son could be released from hospital only after the training was complete.
Six months later, this is what his diabetes management looked like:
Rapid glycaemic fluctuations on a daily basis
Daily hypoglycaemic events due to correctly calculated but still excessive insulin boluses
Daily correction boluses to bring down glycaemic excursions
Multiple overnight glucose checks by his mum and me
Best HbA1c 64 mmol/mol
To our friends and family, he looked like a toddler with delayed development, and we looked like parents stressed due to lack of sleep. We were constantly anxious due to lack of control, we had to cut down our work hours, and weekly conversations with the paediatric endocrinologist and nurses for guidance had limited impact. We explored what medical systems were available in other developed countries and despaired: we already had the best possible tools, apparently.
In October 2017, our paediatric endocrinologist referred us into a closed-loop system trial. On day 2 of looping we saw the first ray of magic, during the night (with no food influencing sugar levels) we saw a steady, safe CGM line. The system was self-adjusting the basal insulin to maintain constant ‘in range’ levels. We could sleep, but more than being undisturbed for 7 hours, we could sleep anxiety-free. No worry if my child will be alive the next morning, not jumping out of bed due to a car alarm out on the street and thinking that was the pump’s alarm, nothing; just sleep, for us and our child.
But we were on a 3-month study and after that we had to give back the pump and technology to the investigators.
In January 2018, after sourcing the hardware, some really kind tech people helping with software and a supportive doctor, we set up OpenAPS (Fig. 2a–c). Over the past ca. 16 months we have been constantly tweaking the system to improve ease of management.
After 1 year of looping:
Daily average time in range (3.6–14 mmol/L), 91%
Daily average carb intake, 128 g
Nighttime hypo treatments in an average month, 1 (one!)
Both low and high glycaemic index foods all able to be managed safely with the system
Best HbA1c, 45.4 mmol
Controlled, safe glucose levels during occasional illnesses
Whilst the condition is not cured, the ability to use an automated system for T1D management is like pressing autopilot on an uncontrolled aeroplane.
The biggest improvement for a toddler has to be flexibility in food management. As a parent, I cannot be sure how much he will eat at mealtimes, but the system compensates by identifying the glucose rise as food comes in. As a result, I can let my toddler be a toddler, without the need for micromanagement.
Finally, the system makes adjustments every 5 minutes, 24 hours a day, factoring in carb amounts, carb timing, glycaemic index, insulin on board, deviations, etc. It does more to manage my son’s diabetes than I can possibly do as a devoted caregiver.
There are some concerns about using a non-licensed product and we take absolute responsibility for this. Current T1D management includes avoiding hypos (the most immediate danger). What is the primary cause of hypo? Although almost always unintended, it is due to excess insulin. Every hypo treatment is because there is too much insulin in the body and the only way the insulin got inside is from a human miscalculating how much to give due to the multitude of variables in blood glucose levels. I’ve got a surprise solution—computers! If you can teach a computer all the rules and variables to micromanage glucose levels by giving small amounts of extra insulin (or reducing insulin), then recalculating every 5 min, bingo, we have our solution: less overtreatment, fewer hypos.
I first became aware of the #WeAreNotWaiting movement a few years ago via people who were into Nightscout, the open-source diabetes data visualization and remote monitoring system. I thought the first wave of people using DIY artificial pancreas systems showed impressive initiative, but didn’t think I would ever join them. It sounded too complicated and techy, and I had great control using a pump (started 1996) and CGM (started 2006) as separate components anyway.
However, from autumn 2015, things changed. Following the birth of my first child in March that year, I was diagnosed with postpartum thyroiditis. Despite my thyroid hormone levels looking fine and stable on daily levothyroxine, after my thyroid quit my blood sugars fluctuated like never before. Having always used tubed pumps, in October 2017 I switched to OmniPod, thinking it would help me to be able to set temporary basal rates and deliver boluses more discreetly. Maybe that would help me feel more in control of my diabetes.
Despite an HbA1c between 42 and 44 mmol/mol, by early 2018 frequent dramatic glycaemic excursions made me think it would be unwise to try to have a second child. That thought was jarring to me because I had never let T1D tell me what to do. T1D has always been a variable I account for, never an excuse not to do something.
At the Advanced Technologies and Treatments for Diabetes (ATTD) conference in February 2018, I heard Aaron Kowalski, now the first person with T1D to serve as President and CEO of JDRF International, talk about his personal experience of DIY looping. I was fascinated and envious. I joined the Looped group on Facebook shortly after ATTD, thinking maybe I would attempt to ‘open-loop’ with OmniPod. In open looping, an independent algorithm running on a phone suggests basal rate adjustments for the user to action manually. That was too complicated for me to attempt, but by mid-June 2018, having learned a lot from Looped and Looped UK, I was gifted a secondhand loopable pump, I bought a RileyLink ($150) and I built my Loop app ($100 for an Apple Developer annual subscription). I already had a serviceable (if ageing) MacBook Pro to run the app build on. I have had NHS funding for Dexcom CGM for over 10 years due to hypoglycaemia unawareness, so the cost of CGM was not an issue for me.
I found the trickiest step was setting up Nightscout, because I misread a line of the instructions. After 20 min of frustration, I posted a request for advice in the Looped UK group and got help to resolve the issue within 15 min. After a week of open-looping with my new setup, I closed the loop on 18 June 2018.
At my routine pump clinic appointment 2 weeks later, my consultant made it clear that I am using an old, out-of-warranty insulin pump at my own risk (fine with me because I have two spares!). She changed the purchase order for my pump consumables to enable me to get the infusion sets and reservoirs I need for looping.
What did I most hope for from using a DIY hybrid closed-loop? I wanted to have the kind of diabetes control I was used to before my first pregnancy, where 12 mmol/L was a big high and I didn’t see it much. I wanted to sleep soundly through the night and wake up with my glucose levels in my target range, so I could start my day with a smile. I wanted to spend time with my son and not worry that I should be doing something about my blood sugar when he wanted to play. Most of all, I wanted to feel like it would be safe to try to have another baby. The only fear I had was that I would not get the results I was looking for.
After 3 months of looping, I felt like things were going really well. My husband and I started trying for a baby. By December 2018, we both felt confident that my diabetes control was less of an issue than my age (37.5). This past January we went on holiday for 10 days. As of the time of writing (19 June 2019) I’m 24 weeks pregnant.
Starting from the day I found out I was pregnant, my time in range for 3.5–7.8 mmol/L (pregnancy closed-loop target range) is 80% (vs. the goal of 70%) and my median high glucose level is 8.9 mmol/L (SD ± 1.0). My mean glucose within my target range is 5.5 mmol/L. The difference in my diabetes control from just prior to using Loop vs. at 1 year of Loop use is illustrated in Fig. 3a–c. I have gotten really used to waking up with glucose levels I like the look of. Being able to deliver a bolus or set a temporary glucose target using my iPhone—not to mention my Apple Watch—still feels like something from the future!
It is impossible to say this pregnancy is going to be absolutely fine—many things could still happen—but so far achieving pregnancy glucose targets has been the least of my worries. That is entirely down to Loop and the support of my diabetes team. At each hospital appointment, I meet a medical student or someone from the wider diabetes and antenatal team who wants to learn about looping and how it works. With Tidepool poised to take Loop through the US Food and Drug Administration (FDA) and European regulatory processes, I hope many more people can have experiences and outcomes to date like mine in the future.