Continuous long-time glycemia monitoring | Role and exclusiveness of the CGMS method
In connection with the above, in the latest edition of the Algorithms for Specialized Medical Care for Patients with Diabetes Mellitus (2015), special attention is paid to monitoring patients with diabetes. So, self-monitoring of glycemia should be carried out several times a day at the onset of the disease or during decompensation, and on therapy with antihyperglycemic drugs — at least 2 studies daily at different times of the day and once a week — at least 4 times a day. With insulin therapy, glycemic control should be carried out even more often, at least 4 times daily. In order to adequately assess the state of carbohydrate metabolism, to determine the risks of developing complications, an indicator such as glycated hemoglobin (HbA1C) is used. However, this indicator gives us information about what the average sugar was in the patient over the last 3 months but does not characterize the situation in a shorter period of time. So, it turns out that all responsibility for controlling sugar, and therefore maintaining compensation, lies entirely with the patient.
Nevertheless, even if all recommendations are followed and careful self-control, information about the dynamics of sugar in the rest of the day remains outside the scope, and we cannot guarantee the absence of hyper- or hypoglycemia.
CONTINUOUS LONG-TIME GLYCEMIA MONITORING
But medicine is constantly improving. In recent years, the method of daily monitoring of glycemia has appeared and is actively used. The essence of the method is continuous automatic measurement of blood sugar levels in the intracellular (interstitial) fluid for several days. For such monitoring, a specialized hardware and software complex CGMS (Continuous Glucose Monitoring System) is used — a highly sensitive method for monitoring blood glucose levels.
The system includes three modules:
- highly sensitive platinum sensor;
- transmitter and monitor;
- a device for exporting data from a transmitter to a computer.
The sensor is an individual disposable device that records the sugar level in the interstitial fluid; it is installed subcutaneously using a special device, practically without pain.
Once installed, a transmitter is attached to the sensor — a small device used to transmit a signal from the sensor to the monitor using Bluetooth technology. The monitor is suspended on the patient’s belt and remains there throughout the entire study period. The convenience of wireless signal transmission is obvious: there is no risk that the wires will be damaged during body movements and the study will be interrupted, and therefore the patient feels freer.
The duration of the study is 3-5 days. The monitor automatically measures blood sugar every 10 seconds and records the average value (from the collected readings) once every 5 minutes. Throughout the study, it is necessary to calibrate the monitor for blood sugar from a finger several times. This requires parallel self-monitoring of sugar on a glucometer. The monitor allows you to enter information about events in the patient’s life (eating or taking medications, physical activity, etc.). This helps to improve the quality of the interpretation of the collected data. After the completion of the study, all the obtained digital information is imported into a computer and analyzed by the attending physician. The monitoring results are presented in the form of graphs and pivot tables with the calculated average values of sugar indicators, the limits of deviations from them, the ratio of hyperglycemia and hypoglycemia in percent for different periods of time.
Automated glycemic monitoring provides the attending physician with the necessary amount of factual information about the nature of changes in sugar levels during the day and allows you to identify trends in deviations. Based on these data, the doctor prescribes the correct treatment tactics or makes timely adjustments to therapy.
ROLE AND EXCLUSIVENESS OF THE CGMS METHOD
Any adjustment to therapy can only be based on reliable data, and the CGMS method becomes an integral part of the management of patients with impaired carbohydrate metabolism. It should be noted that the possibilities of using the method are not limited only to patients with diabetes mellitus. It can be used to diagnose hypoglycemic conditions in people without diabetes, as well as to analyze changes in glycemia in obese patients and detect disorders of carbohydrate metabolism at the earliest stages.
In patients with diabetes mellitus, the technique is used to diagnose the following conditions:
- postprandial hyperglycemia, which allows evaluating the effectiveness of antihyperglycemic therapy and the rate of absorption of various carbohydrates;
- nocturnal hypoglycemia;
- the blood sugar response to exercise;
- hidden asymptomatic hypoglycemia, etc.
The collected and analyzed information makes it possible to individually adjust the therapy, the frequency and time of taking antihyperglycemic drugs, the schedule and degree of physical activity and, of course, nutrition, its qualitative and quantitative characteristics.
Repeated monitoring of glycemia after correction of therapy allows an objective assessment of the effectiveness of changes