The blood glucose values are - just like the blood lipids - among the routine values on the laboratory reports. They are mainly used for the diagnosis and therapy monitoring of diabetes mellitus. But what do the different measured values mean? Why do you have to be fasting for some values? And what does our blood sugar have to do with our life expectancy? In this part of the lab series, we take a look at exactly that.
Sugar in the blood - what do we need it for anyway?
Our body needs energy - and a lot of it. The main mechanism by which our cells obtain energy is glycolysis, the citrate cycle and the respiratory chain. In this process, sugar molecules (glucose) are "burned" with the help of oxygen to produce ATP. ATP is the abbreviation for Adenosinetripphosphate. ATP can also be described as the energy currency of the cell. If we want to move our muscles, for example, we need ATP for our muscle fibers to contract. At rest, our brain is the largest consumer of glucose in the entire body. About 20% of all sugar is consumed by our brain - even at night.
Our cells therefore need "sugar" around the clock so that they can work. For this reason, there is about 5g of glucose in our bloodat all times.
To give you a better idea of what your body does every day, here are a few figures: According to Mergenthaler et al.in 2013, the human brain requires around 5.6mg of glucose per 100 grams of brain matter per minute. With an average brain weight of 1400 grams, that makes 78.4mg per minute. That's 4.7 grams per hour and about 113 grams of glucoseper day. And that's just for your brain!
At least as impressive is the fact how much ATP your body consumes per day. On average, it is around 65 kg or as much as you weigh. Your ATP is recycled around 1000 to 1500 times a day, otherwise we would have to carry around a lot of extra weight
In order to supply our cells with glucose, we have sugar stores in the form of glycogen. Glycogen is a molecule that consists of many glucose molecules strung together. These can be split off if necessary and distributed into the blood by the liver, for example.
Fasting blood glucose, long-term glucose - what types of measurement are there
If you want to know your blood glucose level, there are various ways to measure it. The simplest method is a self-test with test strips and the appropriate meter. You can usually get both at the pharmacy. For this type of test, you need a small drop of blood, which is placed on the test strip and a few seconds later the test device spits out the blood glucose value. The advantage of this method is that it is easy to carry out . However, it only provides a selective insight into the blood glucose metabolism.
A much more informative method is the use of glucose trackers, also called Continuous Glucose Monitor (GGM). As the name suggests, these devices continuously measure your blood sugar and send this information to your smartphone, for example. This allows you to see "live" how your body reacts to different foods. Corresponding sensors are already available to buy for around €100. The lifespan of a sensor is around two weeks - enough time to test your blood sugar reaction to different products!
In addition to these two methods, there are also the following options for assessing blood glucose metabolism. This usually requires a blood sample or a few drops of blood:
- Fasting blood glucose (NPG) : Fasting blood glucose is when you have not eaten for at least eight hours . This value is therefore usually measured in the morning and should not exceed 100mg/dl in healthy people.
- HbA1c : This value is colloquially known as " long-term glucose". It measures the concentration of red blood cells that are loaded with a sugar molecule. As red blood cells have a lifespan of around three months, the blood sugar situation over the last eight to twelve weeks can be estimated . In the case of lifestyle changes or dietary changes, it only makes sense to check the HbA1c value after around three months. High blood sugar levels lead to higher HbA1c values. There are different limits depending on age. In healthy adults the value should be below 5.7%
- Occasional plasma glucose (GPK): This is the blood glucose value independent of food intake. It varies greatly and is not particularly meaningful. The target value is below 200mg/dl .
A blood glucose measurement is easy to perform and provides selective information about the blood glucose level.
High blood glucose levels - what's behind them
If your blood sugar levels are too high, this can be a sign of diabetes mellitus, a metabolic sugar disease. Diabetes mellitus is one of the most common diseases worldwide. The most common variants or types of diabetes are type 1 and type 2. In type 1 diabetes mellitus, our own immune system destroys beta cells in our pancreas. The beta cells produce the hormone insulin. In somewhat simplified terms insulin can be thought of as a key that is needed to bring glucose from the blood into our cells. In type 1 diabetics, this key is missing, which is why the door to the inside of the cell remains locked and the sugar level in the blood becomes too high.
Type 2 diabetics have a different problem. Their cells have become increasingly "resistant" to insulin . So the key no longer works so well. Insulin resistance is the precursor to diabetes and a silent epidemic due to the significantly high number of unreported cases. The good news is that insulin resistance and prediabetes are still reversible .
Do you actually know where the name diabetes mellitus comes from? "Diabetes" comes from the Greek and means " to flow through ", while "mellitus" comes from the Latin and means "honey sweet".
The disease was already known in ancient times - with the main symptom of "sweet" urine. If the blood sugar is significantly too high, the body excretes some of the excess glucose in the urine . As it was not possible to measure blood glucose levels in the past, those affected were recognized by their sweet-tasting urine.
In the German National Health Care Guidelines, the diagnosis of type 2 diabetes mellitus is defined as follows:
At least two values of fasting blood glucose, HbA1c or occasional blood glucose must be pathological . What exactly does pathological mean? Here, too, the guideline contains corresponding threshold values:
| No diabetes | Increased risk of diabetes | Diabetes | |
| Nüchternblutzucker | & lt; 100 mg/dl (< 5.6 mmol/l) | 100 - 125 mg/dl (5.6 - 6.9 mmol/l) | from 126 mg/dl (from 7.0 mmol/l) |
| HbA1c | & lt; 5.7% (< 39 mmol/mol) | &5.7 to 6.4%from 6.5% (from 48 mmol/mol) | |
| occasional plasma glucose | from 200 mg/dl (from 11 mmol/l) |
If the values are not clear, an oral glucose tolerance test (OGTT) can be performed.
Sugar comes in many different forms. Basically, they all promote insulin resistance to a similar extent.
OGTT - what does the oral glucose tolerance test tell me about my blood glucose metabolism?
In the oral glucose tolerance test, you drink a sugar-water mixture consisting of 75mg glucose , which is significantly sweeter than soft drinks such as cola. You measure your blood sugar once before taking the drink and then every half hour after drinking it. The last measurement is taken after two hours. The purpose of this, admittedly somewhat complex, test is to detect insulin resistance and thus impaired glucose tolerance at an early stage. An OGTT is usually always carried out during pregnancy in order to detect the occurrence of gestational diabetes as early as possible. The standard values for this test are defined in the national care guideline for type 2 diabetics as follows:
| No diabetes (normal glucose tolerance) | Increased risk of diabetes | Diabetes mellitus | ||
| Abnormal fasting glucose | Impaired glucose tolerance | |||
| Fasting plasma glucose | < 100 mg/dl ( < 5.6 mmol/l) | 100-125 mg/dl (5.6 - 6.9 mmol/l) | < 126 mg/dl ( < 7.0 mmol/l) | from 126 mg/dl (from 7.0 mmol/l) |
| 2-h after oral glucose | < 140 mg/dl ( < 7.8 mmol/l) | - | 140 - 199 mg/dl (7.8 - 11.0 mmol/l) | from 200 mg/dl (from 11.1 mmol/l) |
Why blood glucose is important for your longevity
We looked at how we measure different blood glucose levels, how to diagnose diabetes mellitus and what insulin resistance is. But why is it all so important for a long, healthy life?
Diabetes is a disease that does not cause any symptoms for a very long time. We don't necessarily notice when our blood sugar is too high. However, we quickly notice the opposite - namely hypoglycaemia. We get cold sweats, get ravenous hunger and can no longer concentrate.
According to data from the Robert Koch Institute, around 4.6 million (7.2%) of all Germans between the ages of 18 and 79 have been diagnosed with diabetes, and the trend is rising. This means that almost one in ten people is "diabetic" . The number of insulin-resistant people is significantly higher, but can only be estimated. Experts suspect that the number of unreported cases is extremely high.
Injecting insulin is particularly typical and necessary for type 1 diabetics. Type 2 diabetics are only required to take insulin in the final stages of the disease.
Excessively high blood sugar levels and the risk of arteriosclerosis - a deadly combination
Excessively high sugar levels attack the blood vessels in our body. As a result, diabetes contributes significantly to the number one cause of death in the western world: Cardiovascular disease. Our blood lipids also make a contribution when they get out of balance.
The number of deaths from diabetes is difficult to estimate. According to this report , there are more than 100,000 deaths per year in the USA alone. Probably even more, considering the role that high blood sugar levels play in the development of cardiovascular disease.
While the death rates for cardiovascular diseases are significantly higher, Dr. Peter Attia describes insulin resistance as the basis on which other life-shortening diseases such as cancer, Alzheimer's and cardiovascular diseases can develop . In his view, it is important to take action against insulin resistance as early as possible.
The studies show that berberine, a naturally occurring pigment extracted from the bark of barberry plants, is involved in the regulation of several signaling pathways and longevity pathways , includingAMPK, NF-κB, sirtuins and several others, has an effect on the body. Among other things, on our sugar metabolism. Berberine (as well as the trace elements chromium and zinc ) have been shown in several scientific studies to have a positive effect on blood sugar levels (especially insulin sensitivity). All three substances are found in combination in the Berberine Mineral Complex from MoleQlar .
Blood sugar levels - why don't we actually measure insulin?
As we have already seen, insulin resistance plays an important role in the development of type 2 diabetes mellitus. Wouldn't it then be easier to measure the insulin directly?
In principle, this is not a bad idea, but insulin does not remain in our bloodstream for very long and this makes accurate measurement difficult. The C-peptideis much better suited for this purpose . This is produced during the manufacture of insulin. In the pancreas, C-peptide and insulin are still connected. In order for insulin to work, the C-peptide must now be split off.
Medical professionals measure the C-peptide to get an indication of the type of diabetes. Type 1 diabetics produce little to no insulin, so in simple terms their C-peptide level is also low. Type 2 diabetics are insulin-resistant. The pancreas produces even more insulin here, which is also reflected in a high C-peptide level .
