Why Monitoring Blood Glucose Matters?
The goals of the research are to assess a part of the health condition through the monitoring of the individual’s glucose level on a daily basis. Although this method also has its drawbacks, it currently represents one of the modern methods of tracking and detecting glucose irregularities.
Glucose, as the primary sugar in the blood, is the main source of energy for cells, especially for the brain and muscles. The concentration of glucose in the blood is constantly changing and depends on diet, physical activity, and hormonal regulation. Too much or too little glucose can lead to various health problems and diagnoses.
What Is Glucose and Why Is It Important?
Glucose, a type of sugar, is the main source of energy in the cells of the body. The body produces glucose by breaking down carbohydrates obtained from food. The blood carries glucose to the cells, where the cells use it to create energy. This generation of energy is called cellular respiration. In the whole process, the brain and muscles are most dependent on glucose as the main source of energy.
Glucose can be obtained by eating fruits, honey, and foods rich in carbohydrates.
Normal Blood Glucose Values
Normal physiological values of glucose in healthy people before the first meal of the day range from 3.9 – 5.6 mmol/L.
Postprandial glucose values are a process of rising and falling of glucose after having a meal. The process lasts within a time frame of approximately 2-3 hours.
Normal postprandial values after a meal in healthy individuals are:
- 30-60 minutes after a meal: <7.8 mmol/L
- 2-3 hours after a meal: <6 mmol/L
If the morning glucose level is too high, it is called hyperglycemia. If the level is too low, then it is hypoglycemia. Hyperglycemia can be a sign of diabetes, while hypoglycemia causes dizziness, sweating, and weakness.
Blood vs Interstitial Fluid Glucose Measurement
Measuring Blood Glucose in the Laboratory and at Home
The laboratory measures blood glucose from a sample. It is most often taken from a finger or a vein in the morning, before the first meal of the day. A technician places the blood sample on the strip and measures the level.
Another way is to measure with a glucometer device, so that the person takes a blood sample by pricking their finger.
Measuring blood glucose is good for determining sudden hypoglycemia or hyperglycemia. The blood immediately reacts to spikes or drops in glucose.
Continuous Glucose Monitoring (CGM) and Interstitial Fluid
Measuring glucose in the interstitial fluid is a determination of the glucose level in the fluid that surrounds the cells under the skin. A glucose monitoring sensor (CGM) helps measure this by staying in a fixed place on the body—on the stomach or the back of the upper arm—for about two weeks.
Learn more about how these devices work in What Is a Continuous Glucose Monitor (CGM) and How Does It Work.
Glucose first rises or falls in the blood and then in the interstitial fluid. Therefore, interstitial fluid measurements show delayed reactions. The usual reaction time between measurements in blood and interstitial fluid is 5-15 minutes. For example, if glucose rises sharply after a meal, a blood sample will immediately show a sudden spike. The sensor will need some minutes until the real value of glucose in the interstitial fluid becomes equal.
During the experiment, blood was drawn once in the laboratory. The glucose value measured in the laboratory compared to the sensor shows a value 10% higher. This value is acceptable compared to the officially accepted deviations, which range from ~8–12%.
👉 Next: Blood Glucose Monitoring Methods: Traditional Testing vs CGM Systems
The goal of this personal glucose monitoring experiment is to understand long-term trends rather than single values. For a complete overview, visit the CGM data–based educational series.
