Continuous Glucose Monitoring: Ride the Waves
Continuous Glucose Monitoring (CGM) is a way to measure glucose levels in real-time, via a sensor that is inserted under the skin into interstitial fluid. A transmitter talks wirelessly with the sensor and sends glucose information to a receiver, pump, and now to a mobile phone. CGM reduces, but does not replace, the need for fingerprick blood tests. Benefits of CGM A fingerprick test gives a single snapshot of blood glucose at a point in time – it does not show which way the glucose level is heading. By contrast, CGM fills in the information gaps, so you can see trends and patterns. CGM helps you to know exactly what your blood glucose does through the night, or at times when it is not convenient to do a fingerprick test such as during exercise, exams or driving. CGM shows not only the direction in which your glucose level is heading, it also shows you how quickly it is moving via the ‘rise’ and ‘fall’ arrows. You can set alarms to alert you when your glucose levels are heading high or low. Software is available that downloads your data and packages it up into neat documents and graphs. I love using CGM in my practice, because seeing all of the information helps me give my patients highly targeted advice. Key things to pay attention to on a CGM graph: Arrow direction: Use the arrows and be proactive. You may be sitting pretty at 6mmol/L right now, but check the arrow direction. It will tell you which way you’re headed so you can act before a hypo hits. Alarm notifications for lows: Be conservative, and set the threshold a little higher than what you think is ‘low’. Remember, the CGM is always about ten minutes behind your blood glucose level. Watch the waves: Compare days to pick up reccurring highs or lows and consider what’s happening at this time – for example, are you giving your breakfast bolus at the right time? Decipher foods that can cause a blood glucose nightmare, such as high carbohydrate meals that are also high in fat or protein. You can get a better idea if what you’re eating is supporting good glucose management, and how to time and dose your insulin too.