Type 1 diabetes: technology to help people cope
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A look at the latest technologies helping people to manage type 1 diabetes.
If you’re one of the 400,000 people currently living in the UK with type 1 diabetes, you’ll be familiar with insulin injections and blood glucose testing. The average person living with type 1 diabetes has around 65,000 injections over their lifetime, together with over 80,000 blood glucose tests.
Insulin is crucial to life. When you eat, insulin moves the energy from your food, in the form of glucose, from your blood into the cells of your body. When the beta cells in your pancreas stop making insulin, glucose levels in your blood start to rise and your body can’t function properly. Over time this high level of glucose in the blood may damage nerves and blood vessels and the organs that they supply.
Treating type 1, therefore, involves replacing the insulin that the pancreas usually produces and carefully monitoring blood glucose levels. There are a number of different ways to do this and an array of clever tech to help, whilst researchers are busy finding new ways to help people achieve better glucose control, with less effort.
For the two main ways of taking insulin there are injections or insulin pumps. The equipment for injections is self-explanatory and comes in the form of insulin pens which can be reusable, where you replace a cartridge in the pen when the insulin runs out; or pre-filled disposable pens.
The vast majority of people who are injecting insulin follow a ‘basal-bolus’ regimen which involves taking two different types of insulin: a long-acting form once or twice a day to keep blood glucose levels stable when not eating (the ‘basal’ injection) and a rapid-acting form before each meal to prevent the rises in blood glucose levels that result from eating carbohydrates or to correct elevated blood glucose levels between meals. This is known as the ‘bolus’ injection.
One of the main advantages of a basal-bolus regimen is that it attempts to mimic how the body releases insulin in people who do not have type 1 and allows for flexibility around what is eaten and when.
Insulin pumps are small, computerised devices, about the size of a smartphone, that mimic the way the human pancreas works. They deliver small doses of short-acting insulin, held in a reservoir, continuously, (basal rate) via a catheter connected to a thin canula, placed into the layer of fat under the skin. The device is also used to deliver variable amounts of insulin when a meal is eaten (bolus), delivered at the touch of a button. Today’s pumps are programmable based on the individual’s needs and have an LCD colour screen to show what you are programming. Most pumps come with built-in bolus calculators to help figure out how much insulin is needed at mealtime based on the user's glucose level and the amount of carbohydrates eaten. Some pumps can read the signal from a separate glucose sensor.
The latest pump from medical device company Medtronic, the MiniMed 640G, has a built-in 'Bolus Wizard' feature to help ensure accurate dosing by taking into account any insulin already in the body, current glucose levels, carbohydrate intake and personal insulin settings to determine the right dose.
In addition, the MiniMed can be connected wirelessly to a blood glucose meter. This meter automatically sends blood glucose values to the pump, allowing more accurate Bolus Wizard calculations and delivers insulin boluses discreetly.
Insulin patch pumps are also available and are worn directly on the body. They have a reservoir, pumping mechanism, and infusion set inside a small case and are controlled wirelessly by a separate device that allows programming of insulin delivery for meals from the patch. The mylife OmniPod Insulin Management System is one such pump and comprises a system with just two elements: the Pod and the Personal Diabetes Manager (PDM).
The small, compact Pod combines an insulin reservoir, infusion set and pump in one unit, which is applied directly onto the skin and supplies insulin for up to three days continuously, without tubing. It’s controlled wirelessly via the PDM, which at the same time also serves as a blood glucose meter and bolus calculator.
Many pumps connect wirelessly with blood glucose meters. These devices measure blood sugar levels using a drop of blood from your fingertip and come in all shapes and sizes. There is a huge range of meters on the market, with over 40 currently available in the UK. They usually have some common components including a lancet to prick the finger, a digital display, and a place to insert the testing strip.
Modern meters include features like calculators to help work out insulin-to-carbohydrate ratios, a USB connection that allows results to be read on a computer, and lights so that they can be used in the dark. There are also ‘strip free’ meters with 50 tests stored on a rotating cassette. There are now many brands to choose from, offering variations on the latest technology such as Roche’s new strip-free Accu-Chek, an all-in-one system combining tests, lancets and a finger pricker in one device; Bayer’s Contour which connects to its own app to capture all of your blood glucose readings, presenting the results in a simple, personalised way; and WaveSense from AgaMatrix Europe Ltd, on which you can track glucose, insulin, carbs and weight to help visualise trends.
Some pumps connect wirelessly with continuous glucose monitoring (CGM) devices that are inserted under the skin and monitor blood sugar levels all day long, providing information every few minutes. You can track whether your glucose is high or low, and see how your glucose levels vary, for example, while you are sleeping, after you eat, when you exercise, or when you are feeling unwell.
CGM has a sensor telling you how much glucose there is in your tissue fluid and is inserted into the skin. This is connected to the transmitter which is worn on the skin and communicates with the receiver, usually wirelessly. The receiver records results and displays them on a pager-sized device often worn on a belt.
The information CGMs provide is useful for analysing the trend of your glucose levels rather than the reading at any particular moment. Research suggests that using a CGM can help reduce your overall blood glucose control over the usual three-month testing period, without increasing the risk of a hypo (very low blood sugar level). They can help you maintain target blood glucose levels, and limit the risk of hypoglycaemia if they are used on a daily basis.
All current CGM systems have a display showing glucose level, trend information, alarms and the ability to download data and view graphs and statistics. Medtronic’s CGM can be used as a separate system or linked to the Veo insulin pump. The company also makes a system which records CGM readings for later reading on a computer, without displaying it to the wearer. Animas’s Vibe insulin pump can be linked to its Dexcom system; and Abbott have a separate system which is licenced for use in those aged 18 or older. Its FreeStyle Navigator II CGM system has a 30m range between transmitter and receiver and incorporates early warning alarms to anticipate highs and lows.
Then there’s flash glucose sensing, a new development in glucose monitoring that uses a sensor the size of a £2 coin that sits on the back of the arm with a probe just under the skin. By scanning or ‘flashing’ the sensor with a scanning device, you get your blood glucose level, a graph of your blood glucose level for the last eight hours, and a direction arrow showing if your levels are going up or down.
There are also a number of apps on the market to help you stay on top of your diabetes management. If you sometimes forget whether you’ve injected, check out the following: Gocap, a device that knows the amount of insulin in your pen and measures the time of your injection and the remaining amount of insulin; Timesulin, which has a feature that automatically counts the time since you last removed the cap; and InsulCheck, which, for extra accuracy, has a timer based on when you inject, rather than when you replace the pen’s cap.
Current research in the treatment of type 1 is focused on developing new ways to lighten the burden of managing the condition, helping people to achieve better glucose control, with less effort. Top of the list is pioneering work on a ‘closed-loop’ system, or ‘artificial pancreas’ (AP), with the US Food and Drug Administration having recently announced its approval of the Medtronic MiniMed 670G hybrid closed-loop system, the first device ever approved to automate the dosing of insulin in type 1 diabetes.
AP technology combines an insulin pump, a CGM and a computer algorithm that uses the information it gains from the CGM sensor to tell the insulin pump how much insulin it should give. It offers a sophisticated, innovative solution to managing the condition and marks a significant milestone in research in the field.