Blood sugar

Blood glucose level at a glance

Sugar - especially glucose - plays a central role in the human body. Many cells prefer to use it as it is readily available and provides energy quickly. Especially the Brain is heavily dependent on glucose and needs around 150 grams a day when at rest. To ensure this supply is maintained, there is always a certain amount of sugar in the blood. 

The blood glucose level is not a fixed value, but changes depending on the time of day, activity and food intake. It rises after eating because carbohydrates are broken down into glucose in the digestive system and absorbed into the bloodstream. Physical activity causes it to fall, as muscles consume more sugar. Hormonal fluctuations also contribute to these natural changes. The body uses a finely tuned system to ensure that blood sugar levels neither rise too high nor fall too low.

Hypoglycemia

Hypoglycaemia describes a condition in which the glucose concentration in the blood drops and falls below the normal level. The brain in particular reacts sensitively, as it constantly needs energy. The causes are usually longer breaks between meals, very intense physical exertion or fluctuations after high-sugar meals. When the blood sugar level drops, the first signs are rather mild, such as a loss of concentration, minor thinking errors, shaky hands or a slight feeling of dizziness.

To counteract this, the body immediately activates several mechanisms. Hormones such as adrenaline and glucagon cause glucose to be released from the liver and muscle stores. Cortisol can also contribute to the formation of new glucose in prolonged situations. At the same time, the brain sends hunger signals that ensure a supply from outside. If the deficiency persists for longer, the symptoms intensify: dizziness, weakness or visual disturbances are possible. In most cases, however, the blood sugar level is quickly stabilized again, as the body's own systems work very reliably.

Hyperglycemia

The counterpart to undersupply is hyperglycemia, i.e. an increased concentration of glucose in the blood. In the short term, this is completely normal and part of the digestive process: after a meal, carbohydrates are converted into glucose, absorbed and the blood sugar level rises. The body reacts to this by Pancreas secretes insulinwhich enables the uptake of glucose into the cells. Normally, the level then falls back to the initial level.

It becomes problematic if the blood glucose level remains permanently high. At very high concentrations, the fluid balance changes, as glucose binds water. In this case, the body excretes sugar in the urine, whereby fluid is lost at the same time. Glycation can also occur: Glucose attaches itself to proteins or fats and changes their structure. The resulting so-called "AGEs" (Advanced Glycation Endproducts) can affect various tissues. The HbA1c value serves as a long-term marker, which indicates the average level of sugar in the blood over the last few weeks.

Hormones and regulation

The two hormones insulin and glucagon are at the center of regulation. Insulin is formed in the beta cells of the pancreas and ensures that Sugar is absorbed from the blood into the muscle and fat cells. It acts like a key that opens the "doors" to the cells. In addition, it promotes storage in the form of glycogen and contributes to the Blood sugar level drops again.

Glucagon is the Opponent. It is produced in the alpha cells of the pancreas and activates the Breakdown of glycogen in the liver, so that Glucose into the blood is released. This causes the blood sugar level to rise again if the concentration is too low. Other hormones such as adrenaline, cortisol and growth hormone also have an effect, which ensure the energy supply, particularly in stressful situations.

This interaction works like a set of scales: after a meal Insulin lowers the blood sugar levelduring periods of fasting or Exercise increases glucagon again. This keeps the concentration within a stable range that prevents both undersupply and oversupply.

Insulin resistance

Insulin resistance is when the body's cells react less sensitively to the insulin signal. Normally, insulin binds to a receptor on the cell surface and triggers the uptake of glucose. If this reaction is weakened, more sugar remains in the blood, while less arrives in the cells.

The development of insulin resistance has various causes. Frequent blood sugar spikescaused by heavily processed Carbohydratesare considered to be a significant factor. Lack of exercise also contributes, because the muscles are the biggest consumers of glucose. Another point is the so-called visceral abdominal fat, i.e. fatty tissue around the internal organs. It releases messenger substances that can disrupt the effect of insulin. Increased amounts of free fatty acids in the blood also impair signal transmission.

In the early phase, the body can still compensate by the pancreas releasing more insulin. In this way, the blood sugar level initially remains normal, but the insulin levels are already elevated. Over time, this extra work can no longer be maintained and the blood sugar rises. This stage is known as Prediabetes.

In the long term, insulin resistance causes blood sugar levels to remain elevated more frequently and at the same time changes the fat metabolism. Insulin normally inhibits the breakdown of fat and promotes the build-up of energy reserves. With permanently high insulin levels, fat is increasingly storedwhich further increases the imbalance. The pancreas is also constantly required to produce more and more insulin.

Glycemic index

Another aspect of blood sugar regulation is the so-called glycemic index. It describes, how much a food raises the blood sugar level compared to glucose. The reference value for glucose was set at 100. Food with a high value let the Fast blood sugar level and strong risewhile foods with a low value cause the increase to be slower and less pronounced. The GI therefore provides an orientation as to which carbohydrates are more likely to cause rapid changes and which are more likely to cause more even changes.

Conclusion

Blood sugar levels are subject to constant fluctuations. Both hypoglycaemia and hyperglycaemia show how sensitively the system reacts. Insulin and glucagon are two hormones that work together to ensure that the supply remains stable. Other hormones intervene to provide support when particular stresses occur. However, if insulin resistance occurs, this balance becomes unstable. Lifestyle factors such as diet, exercise and body fat percentage influence how stable the regulation is. The glycemic index provides additional guidance on how different foods can affect blood sugar levels.