In the case of a lipid metabolism disorder, the blood levels of certain fats are outside the normal range. There are many different shapes. The most common are caused by an unhealthy lifestyle, often in connection with unfavorable family dispositions. As a rule, the levels of one or more blood lipids are increased, such as cholesterol, certain sub-forms of cholesterol or triglycerides. Other disorders are rare.
The body needs fats for many very important processes. However, too many fats in the blood can increase health risks. In most cases, the risk of cardiovascular diseases such as arteriosclerosis, thrombosis, angina pectoris, heart attack, stroke and aneurysms increases. Liver diseases can also develop as a result. Treatment aims to bring the values back down. Although this can be achieved with medication, the focus is on lifestyle changes.
Lipid Metabolism Disorder Causes And Risk Factors
There are around 70 different lipid metabolism disorders. The majority are rare forms. The variants can be grouped according to which fats or lipoprotein values have changed. Basically, the disorders are divided into primary and secondary disorders according to their origin. For the most common forms, it also depends on whether cholesterol, triglycerides, or both are outside the recommended range.
- Primary, hereditary forms: Genes play a role in around four out of five lipid metabolism disorders (80%), but are usually not solely responsible for them. External factors (poor diet, obesity, lack of exercise, diabetes mellitus, smoking, etc.) must also be present, particularly in the case of the widespread forms, for the disorder to develop and persist. The most common forms of this category are familial hypercholesterolaemia, in which several genes are altered, and familial combined hyperlipidemia. Lipid metabolism disorders that can be traced back to a single altered gene are rare. Affected people often develop symptoms in their childhood.
- Secondary forms based on underlying diseases, medication or alcohol abuse: Diseases and substances can interfere with and disrupt lipid metabolism. Common causes include diseases such as diabetes mellitus, hypothyroidism, liver disease, obesity, chronic kidney failure and anorexia or drugs from the families of estrogens, beta-blockers, glucocorticoids (e.g. cortisone) and diuretics as well as alcohol abuse.
The forms with increased values (hyperlipidemia) are further differentiated by experts according to which values have changed. The most important hyperlipidemias are:
- Hypercholesterolaemia – only cholesterol is elevated, predominantly LDL cholesterol
- Combined hyperlipidemia – cholesterol and triglycerides are elevated
- Hypertriglyceridemia – only triglycerides are elevated
In addition, texts sometimes list forms in which the values for total cholesterol and triglycerides are correct, but the ratio of certain lipoproteins to one another is not correct. This usually means that there is too much “bad” LDL cholesterol circulating in the blood and not enough “good” HDL cholesterol.
Risk factors
Many factors can contribute to a lipid metabolism disorder. These include some that are present at the onset, such as familial predisposition, medical conditions, and medications. The most important include:
- Age
- Male gender
- Overweight, especially abdominal
- Lack of exercise
- Wrong diet, particularly high proportion of animal fats or saturated fatty acids
- Smoking
- Alcohol abuse
- Stress
- Diseases (e.g. high blood pressure, diabetes)
- Medication
Lipid Metabolism Disorder Symptoms
The most common forms rarely trigger special symptoms within the usual framework. But they increase, usually together with other factors, some health risks - especially those for the heart and circulatory system. Signs of a strong, long-lasting lipid metabolism disorder or its consequences can be:
- Yellowish-brownish to reddish nodules on eyelids, elbows and other parts of the body
- Clouded rings around the cornea of the eye
- Pain in the upper abdomen, e.g. with inflammation of the pancreas or liver
- Increased deposits in the arteries (arteriosclerosis) can lead to pain in the chest (angina pectoris), in the legs («intermittent claudication», peripheral arterial occlusive disease [PAOD]) or even to a heart attack or stroke.
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| Blood test |
Visible or noticeable consequences only become apparent later. In some cases, they and the damage associated with them can then no longer be reversed. It is therefore advantageous if lipid metabolism disorders come to light beforehand, preferably as early as possible. Experts recommend regular blood tests from the age of 35. The blood tests determine values for several different fats or lipoproteins, as the transport forms are called. Because fats, including cholesterol and triglycerides, do not dissolve in water and therefore also not in the blood. The main classes of lipoproteins are:
- LDL (Low-Density Lipoprotein): It is always loaded with cholesterol and delivers it to the cells. When there is too much LDL cholesterol in the blood, it can build up on artery walls. That is why LDL cholesterol is considered “bad” cholesterol, especially when its level is elevated.
- HDL (High-Density Lipoprotein): It collects excess cholesterol from cells and transports it to the liver. This ensures that the body eliminates cholesterol. That is why HDL cholesterol or a high value is considered “good”.
- VLDL (Very Low-Density Lipoprotein): It supplies fat and muscle cells with energy in the form of triglycerides. VLDL that have unloaded their triglycerides reload in the liver.
- Chylomicrons: They arise in the small intestine and enter the bloodstream via the lymph. They contain mainly triglycerides and only a little cholesterol.
Tests commonly measure blood levels of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides.
Lipid Metabolism Disorder Treatment
The aim of the treatment is to lower blood lipid levels to a level that keeps the risks for those affected as low as possible. Fat levels have to drop the lower the more risks are present, such as past heart attacks, obesity, high blood pressure, diabetes and smoking. Slim, athletic people who have never smoked and otherwise have normal blood levels can cope better with higher blood lipid levels than overweight, non-athletic smokers with diabetes and high blood pressure. Depending on the individual risk, doctors set different target values for blood lipids. In order to achieve them, the first thing to do is to make lifestyle changes. They are hugely important and can eliminate the need for medication or reduce the doses needed.
- According to most experts, changes in the menu make sense. Ingesting less cholesterol with food is only useful for certain dyslipidemia. Otherwise, the body simply produces more cholesterol itself when the supply decreases. It can be more helpful to limit the fat content of the diet to a maximum of 30%. It is important to ensure that you consume more unsaturated fatty acids and less saturated ones. One should prefer vegetable fats and avoid animal ones. However, eating fish regularly is considered good for the blood vessels. Sometimes patients need to reduce calorie intake in general, which they can do by eating less fat or fewer carbohydrates in the diet. Some have to give up alcohol. With some forms, it is unwise to switch to a low-fat diet. The diagnosis determines which diet plan is suitable as treatment. There is nothing wrong with eating plenty of fresh fruit, vegetables and foods that are high in fiber. Many of those affected find professional nutritional therapy helpful, also because it shows many ways of eating healthily and still enjoying it.
- Changing your lifestyle is worthwhile if you have unhealthy habits. In addition to an unhealthy diet, these are usually excessive weight, lack of exercise, smoking, heavy alcohol consumption and the like. Such risk factors should be eliminated or at least mitigated. Regular physical activity helps with weight loss. Studies have shown that endurance sports in particular have clearly improved the ratio of lipoproteins. Blood pressure and blood sugar also benefit from it. Many of those affected could do without medication if they were disciplined in making lifestyle changes.
- Medications help lower blood lipids to target levels. Attempts to achieve these values are usually first made by making lifestyle changes alone. If that is not enough, most substances from the statin family are used. In the case of poor tolerability and for special forms, there are alternatives such as fibrates or nicotinic acid. If nothing helps, the last resort in severe disorders is blood washing. It only happens on very rare occasions. Those affected must also treat concomitant diseases, especially if they increase the cardiovascular risk. Many patients take other medications for this purpose.
Prevention
A lipid metabolism disorder can be prevented by avoiding the risk factors as much as possible. The best people are relaxed people who have never smoked, never been overweight, exercise a lot, drink little alcohol and eat healthily. This not only reduces the risk of lipid metabolism disorders and cardiovascular diseases! Smokers should definitely avoid nicotine. For the other risk factors, it is advisable to keep them at least within reasonable limits: neither weight nor lack of exercise, alcohol consumption and the quantity of unfavorable foods should be too far outside the healthy recommendations. Medication can also help prevent it. Statins not only lower blood lipids, but also the risk of heart attacks and strokes - especially after a heart attack or stroke has already occurred. It has not been clearly clarified whether the drugs also reduce the risk beforehand.