Contrary to popular belief, cholesterol is not inherently bad. But what exactly is cholesterol and how is it related to your kidney? What tasks does it perform in your body? What are your target cholesterol levels and how can you positively influence them? You can find the answers to these question in this blog article.
What is cholesterol and how is it produced?
You may have heard about the so-called blood fats. Cholesterol is one of them. Now the word blood fats sounds rather negative at first. After all, you are often taught that fat is not necessarily the basis for a healthy diet. But cholesterol performs many important tasks in your body. For example, it is an important component of the outer shell of your body cells (=cell membrane). Cholesterol is also used to produce various endogenous messenger substances (=hormones) as well as bile, which is a digestive juice. Since the body needs cholesterol, most of it is actually produced by the body itself and the rest is taken in through food.
What are the different forms of cholesterol?
The transport medium for important substances within the body, e.g. oxygen, hormones and our cholesterol, is the blood. As the name blood fats - to which cholesterol belongs - already reveals, cholesterol is a fat-like substance. Our blood, on the other hand, is largely made up of water. If you have ever tried to dissolve a vegetable fat, such as olive oil, in water, you know that this is almost impossible. The reason for this is that fats are difficult to dissolve in water. So that our cholesterol can be transported from A to B in our blood, it is packed into small packages consisting of proteins, fats and other components. This allows it to dissolve in water and be transported in the blood. These packages are called lipoproteins. So cholesterol does not just float around freely in your blood, but is always transported in the form of lipoproteins.
This is also the reason why a distinction is made between different forms of cholesterol. If you take a look at your last lab report, you will often discover HDL and LDL cholesterol in addition to the so-called "total cholesterol". Total cholesterol is a laboratory value that is measured in the blood and in which all "cholesterol packets" are added together.
What is HDL cholesterol?
HDL (=high density lipoprotein) cholesterol is the name given to the "transport package" that brings cholesterol from the body's cells to the liver. There it is either excreted or further utilized. HDL is said to have a positive effect on your blood vessels and protect them, even though the connection has not yet been clearly proven scientifically. Therefore, HDL is often referred to as "good cholesterol". In summary, HDL transports your cholesterol to the liver, where it is then used.
What is LDL cholesterol?
Another of the packets used to transport cholesterol is called LDL (=Low Density Lipoprotein). This is the pathway by which cholesterol is carried from the liver to various cells in the body. LDL cholesterol is often colloquially referred to as "bad cholesterol" because it plays a central role in the development of hardened vascular walls (=arteriosclerosis). This increases the risk of heart attacks and strokes, among other things. In summary, LDL transports your cholesterol from the liver to the rest of the body.
How are cholesterol levels and my kidney function related?
Too much LDL cholesterol damages your blood vessels and can lead to hardening of your vessel walls (=arteriosclerosis). Why is this dangerous? Your blood vessels carry important nutrients to your various organs. If they harden, the blood can no longer flow as it should. As a result, your organs may not be supplied with sufficient nutrients and oxygen and may be damaged as a result. Your kidneys are particularly sensitive to poor blood flow, as are your heart and brain. If your kidneys are already not functioning so well, or if you have had a kidney transplant or are on dialysis, you should take particularly good care of your kidneys and avoid high LDL cholesterol levels.
What are the target values for my cholesterol?
Now you know a lot about cholesterol, what it does, and the different forms it takes in the body. But what target values should you reach? Your target cholesterol levels are based primarily on your personal risk of developing cardiovascular disease - your kidney disease itself plays a less important role.
Total cholesterol target
If you are at low risk of developing cardiovascular disease, your total cholesterol - the amount of all "cholesterol packets" in your blood - should be below 190 mg/dL. If this value is exceeded, we speak of a pathologically elevated cholesterol level in the blood (=hypercholesterolemia). This increases the risk of developing cardiovascular diseases (e.g. heart attacks and strokes).
Target value of LDL
As you already know, LDL plays a central role in the development of vessel wall hardening (=arteriosclerosis) and should therefore be as low as possible. Your personal target value for LDL changes depending on how many additional risk factors for the development of cardiovascular disease you have. In addition to elevated LDL cholesterol levels, the main risk factors include high blood pressure (=hypertension), existing diabetes (=diabetes mellitus), obesity and smoking. If you have few of these risk factors, your LDL target value is less than 116 mg/dL. However, if you have an increased risk of developing cardiovascular disease, your LDL level should be less than 40 mg/dL. As you can see, the difference is very large. It is therefore worthwhile to talk to your family doctor or nephrologist about this topic. In general, the lower the LDL cholesterol level, the better.
Target value of HDL
As you have already learned, HDL is the "good" cholesterol. Therefore, higher values are good for your health. Again, your personal risk factors for cardiovascular disease play an important role. Your kidney disease also has little influence on your HDL target value. But it does make a difference depending on your gender. If you have few risk factors, your HDL level should be more than 45 mg/dL as a woman. For men, the target value is more than 40 mg/dL. In this case, too, it is worth discussing the topic in more detail with your physician.
How can I positively influence my cholesterol levels?
Low LDL and total cholesterol levels and higher HDL levels have a positive effect on your cardiovascular system and kidneys. So what can you do now to improve your individual levels?
Exercise
Exercise is generally good for you and your health. Regular exercise also has a positive effect on your HDL level. It can increase as a result. In general, exercise significantly reduces the risk of developing cardiovascular diseases. But how much exercise are we talking about? It is recommended that you do at least 30 minutes of exercise five times a week, during which you break a light sweat. Of course, the limit for this varies depending on your fitness level. But even everyday activities, like walking 10,000 steps a day, have a positive effect on your health. To motivate yourself, you can use a pedometer on your cell phone or in a watch, for example.
Diet
A healthy and, above all, balanced diet in combination with exercise not only helps you to lower your LDL levels, but also supports you in maintaining or achieving your ideal weight. In this way, you kill two birds with one stone, in other words, you reduce two risk factors for cardiovascular disease at the same time: elevated LDL cholesterol levels and obesity.
What exactly is meant by a healthy and balanced diet in relation to cholesterol levels? In this context, the word "Mediterranean diet" comes up again and again. This diet mainly avoids animal fats in the form of sausage and red meat. Instead, you can eat more vegetable fats, which are contained in olive oil and nuts, for example. Whole grain products are also part of the Mediterranean diet. It is also recommended that you eat fish twice a week and avoid fast foods as much as possible. This is because they often hide sugar and "unhealthy" fats. If you're looking for ideas for healthy and varied recipes, take a look at the Mizu app. Depending on the status of your kidneys, you'll find lots of delicious suggestions with personalized nutritional calculations.
Specifically, the Mediterranean diet can lower your LDL levels and blood pressure, thereby protecting your blood vessels. It also has a positive effect on your kidney function, especially after kidney transplantation and in case of kidney insufficiency. Note: especially if you are currently dialyzing, you may have other dietary recommendations such as a low potassium diet.
Medication
If your lifestyle - i.e. a healthy diet and regular exercise - has not yet enabled you to fully reach your cholesterol target values as set by your doctor, then medication can provide you with additional support.
First and foremost, statins are used for this purpose. They stop an important step in the formation of LDL. As a result, your body produces less LDL overall. Less LDL means less risk of hardening of the vascular walls (= arteriosclerosis) and thus less risk of poor blood supply to your kidneys or other organs, which could lead to damage.
