Metabolic disorders: what are they, characteristics and most common types

The body carries out multiple chemical reactions that make up metabolism. Without them, we would not be able to obtain energy or simple molecules from food and, therefore, our body would not be able to carry out its vital functions.

However, there are cases in which due to a genetic error, the substances in charge of degrading complex molecules, enzymes, are not produced properly, causing multiple problems metabolic.

The body produces about 75,000 enzymes and, if any of them are not present at the proper levels, a metabolic disorder can occur. Next we will see what are metabolic disorders and which are the most common.

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What is a metabolic disorder?

Both the human body and the rest of the living beings are containers of metabolic reactions, which allows us to compare the forms of life with factories of chemical reactions. Metabolism includes any chemical reaction that occurs in the organism of a living being, whether it is replicating DNA, degrading fats, carbohydrates and proteins, repairing tissues, producing melanin ...

The different compounds that our body requires to function are obtained through thousands of metabolic routes that occur inside cells. These chemical reactions occur thanks to the action of protein molecules, enzymes, of which our body has many different ones, more than 75,000. There is practically an enzyme for each substance that we introduce into our body and each of them specializes in some phase of a metabolic pathway.

It happens that, sometimes, and because of genetic errors, some enzyme cannot be synthesized or does it in a incorrect, making the metabolic pathway you were expected to participate in cannot be completed adequately. This brings with it problems, either in the form of accumulation of substances as they are not properly degraded or, On the contrary, there is too much enzyme for a substance and it is present at very high levels. low. Whatever the specific situation, this causes metabolic disorders.

Metabolic disorders are pathologies that occur when there is an error in a gene sequence, which makes that an enzyme cannot be adequately synthesized and, consequently, the degrading substance is present in harmful amounts for the organism, either by excess or by shortage. This enzymatic defect brings with it complications for the whole organism, of varying severity in function of the affected metabolic pathway and whether or not the enzyme involved is essential for the life of the affected.

As there are many enzymes in our body, there are hundreds of different metabolic disorders and, naturally, their prognosis varies between them. Some may involve simple temporary discomfort, others require constant clinical admissions and need extensive follow-up, and in some cases can even be fatal. Because they are often caused by genetic error, metabolic disorders can rarely be cured. However, by following a healthy lifestyle and avoiding exposure to certain substances, the prognosis can be very favorable.

While most metabolic disorders are rare seen individually, the truth is that about 40% of the population has some medical condition linked to poor synthesis of an enzyme or poor metabolism of a substance. That is, the group of metabolic disorders are relatively common, although it is true that there are extremely rare and life-threatening metabolic diseases.

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The most common metabolic disorders

As we have seen, a metabolic disorder develops when, due to a genetic error, there are problems in the synthesis of one or more enzymes. Depending on how altered the production of the enzyme involved is, which metabolic pathway it affects and in which of its stages the alteration is found, one or another pathology will appear. Among the most common metabolic disorders we find:

1. Obesity

Medically speaking, obesity is a complex disease. This medical condition has a multicomponent origin, being influenced by both genetics and environment, and in recent decades it has become a true pandemic in many countries. There are those who consider it the pandemic of the 21st century, since about 650 million people in the world suffer from obesity, and 1.9 billion, are overweight.

Although obesity requires a body mass index (BMI) greater than 30 to be diagnosed, the truth is that what most identifies a person with this disease is having excess fat. This is important because there are people whose BMI is greater than 30 but they do not have fat accumulation, as is the case of bodybuilders, and therefore they do not have obesity.

Obesity affects the body in multiple ways. While being thin is not synonymous with being healthy, being obese is confirmation that you are not healthy at all. Having excess body fat is associated with a greatly increased risk of disease cardiovascular disease, diabetes, cancer, bone pathologies, and even mood and learning.

It may come as a surprise, but the causes of obesity remain unclear. Although one of its causes that seems to be the most obvious is eating too much, the truth is that many experts say that they still do not know if this is the real reason or, rather, it is a consequence. That is, first you were obese and then you had the need to eat in large quantities.

Obesity is considered a metabolic disorder, as it appears that is associated with problems in the metabolic routes of assimilation of certain nutrients. A genetic component has been seen in the development of this condition, which means that it is true that some people may be predisposed to obesity if there is a history of obesity in their family disease.

Nevertheless, The fact that there is a genetic predisposition to suffer from obesity does not mean that things cannot be done to lose body fat and improve health. Several environmental factors such as hours of sleep, physical exercise and diet influence this predisposition. Therefore, whatever its real cause, the best way to treat it is to start lifestyle changes, improve diet and even go to psychotherapy if there is a possibility of a Eating Disorder (TCA).

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2. Diabetes

Diabetes is an endocrine and metabolic disease that can be of four types:

• Prediabetes: near diabetes, curable.
• Gestational diabetes: temporary diabetes associated with pregnancy.
• Type 1 or child-youth diabetes: genetic in origin
• Type 2 or acquired diabetes: caused by being overweight or poor dietary habits.

Diabetes is a metabolic disorder because there are defects in the synthesis or action of insulin, the hormone responsible for regulating blood sugar levels. Due to this problem in the production of insulin, glucose cannot be properly metabolized and is circulating freely in the blood, causing serious damage to the body.

Some symptoms of diabetes are weight loss, weakness and fatigue, blurred vision, and the appearance of sores. In the long term, this disease can bring with it even more serious complications, such as diseases cardiovascular disease, kidney damage, mood disorders such as depression, and even death.

Prediabetes and gestational diabetes have a cure, but the other two cannot. Type 1 and 2 diabetes are chronic diseases that require lifelong treatment, as they are not glucose metabolism can be restored to normal and injections of insulin. To ensure that their health does not deteriorate further, people with diabetes must constantly monitor their blood glucose levels.

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3. Phenylketonuria

Phenylketonuria is an inherited metabolic disease in which, due to genetic failure, those who present it do not have the enzyme responsible for degrading phenylalanine, a very common amino acid found in foods rich in protein. Phenylketonuria patients, when introducing phenylalanine into their body, cannot digest it and it ends up accumulating.

This disease causes very fair skin and blue eyes, since the melanin pigment cannot be synthesized if phenylalanine is not degraded. The accumulation of phenylalanine damages the central nervous system, which causes intellectual disability. Other problems associated with phenylketonuria are strange skin odors, bad breath, and foul-smelling urine. delays in body development, behavior problems, microcephaly, skin rashes and, of course, disorders neurological.

The only way to avoid the symptoms of phenylketonuria is eating an extremely low-protein diet for life. Common foods such as meat, milk, eggs, legumes and fish are full of phenylalanine and therefore cannot be eaten by patients with phenylketonuria.

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4. Lactose intolerance

Lactose intolerance is an extremely common metabolic disorder globally (75% of the world population), although in Europe it is relatively rare, especially in the Nordic countries, Great Britain and north-central Europe, with less than 15% of their population with this trouble.

Those who suffer from it have problems in the synthesis of lactase, an enzyme produced in the small intestine and that breaks down lactose, substance present in animal milk derivatives. Lactase converts lactose, a substance that cannot be assimilated by the body, into glucose and galactose, which they are.

Lactose intolerance is varied, with more serious cases than others. Depending on how affected lactase production is, more or less severe symptoms will occur after eating lactose products, including flatulence, bloating, diarrhea, vomiting ...

There is no cure for this disorder, since there is no known way to increase lactase synthesis. Yes, there are drugs that help digest, but they do not work for everyone. The best way to avoid symptoms of lactose intolerance is to cut down on dairy products and get calcium from other foods, such as broccoli, soy drinks, oranges, salmon, spinach...

5. Hypercholesterolemia

Hypercholesterolemia is a metabolic disorder in which, due to genetic factors combined with an unhealthy lifestyle, blood levels of LDL cholesterol (low-density lipoprotein, "bad cholesterol") are above normal, while HDL (high-density lipoproteins, "good cholesterol"), below.

The most common hypercholesterolemia is familial, associated with a hereditary genetic predisposition, although with a healthy lifestyle you can prevent. More than 700 possible genetic mutations have been found that can cause its appearance, which would explain why it is so frequent.

This disorder has as its main problem that it does not show signs of its existence until it is too late, when it has already been produced cholesterol accumulation in the blood vessels and have clogged them, causing vascular problems such as heart attacks or ictus. It is for this reason so important that, if it is known that there is a family history, frequent blood tests.

6. Hyperlipidemia

Hyperlipidemia is a metabolic disorder in which there is an increase in triglycerides and cholesterol. It is usually due to an inherited genetic disorder, although it must be said that other factors such as poor diet, alcoholism and being overweight can worsen this medical condition.

The best way to avoid severe symptoms of hyperlipidemia is reducing the consumption of meats (especially red ones), fatty dairy products, industrial pastries and any other food with a high amount of fat, since they cannot be metabolized well and will accumulate in the blood.

Symptoms associated with this medical condition include chest pain at an early age, leg cramps, and loss of balance. People with hyperlipidemia have an increased risk of suffering myocardial infarction and cerebrovascular accidents, among other vascular problems.

7. Porphyria

Porphyria is a disorder in which there is an accumulation of porphyrins due to problems in the metabolism of these substances. Porphyrins are essential to fix iron and transport oxygen in hemoglobin but that, when they cannot be degraded or more than necessary are synthesized, it can result in an accumulation of them in the blood, which brings with it several problems.

This metabolic disease is inherited and can manifest itself in multiple ways. Sometimes it only causes skin problems, while other times it can cause nerve damage, causing breathing difficulties, abdominal pain, chest pain, hypertension, seizures, muscle pain, anxiety, and even death.

There is no cure for porphyria and treatment is limited to relieving symptoms when attacks of the disease occur. Porphyria attacks can be more or less prevented by leading a healthy lifestyle, reducing the stress, avoiding sun exposure, not drinking alcohol or smoking, and avoiding being too long without eat.

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8. Wilson's disease

Wilson's disease is an inherited metabolic disorder in which there are problems metabolizing copper, a metal that accumulates in the liver, brain, and other vital organs. Copper is obtained through food and is essential to keep our nerves, skin and bones in good health, but it must also be correctly eliminated.

This metal can accumulate when there are problems in the synthesis of the bile enzymes that are responsible for eliminating it. If this situation occurs, it can lead to problems such as liver failure, blood disorders, neurological diseases and psychological problems.

Although there is no cure for Wilson's disease, there is there are drug treatments that help fix copper so that the organs expel it into the bloodstream and, thus, is eliminated through the urine. Thanks to medications, people with this disease can lead a normal life although they must avoid foods rich in copper such as shellfish, nuts, chocolate or liver.

9. Atherosclerosis

Atherosclerosis is a metabolic disorder whose cause is of genetic origin and in which there are alterations in the metabolism of fats. In patients with this disease, fatty matter accumulates on the walls of the blood vessels., causing plaque formation and hardening of the arteries, which become stiffer and narrower.

Hardening and narrowing of the arteries causes blood flow to be affected, slowing down because it has difficulty flowing through the circulatory system. There comes a time when the fat plates are so dense that, directly, the flow is blocked and, depending on the affected region, can cause death.

Atherosclerosis is the main cause of arterial insufficiency which, in turn, can cause vascular diseases such as heart attacks, ictus, heart failure, arrhythmias ...

As a disease of genetic origin, atherosclerosis has no cureBut yes, lifestyle changes and drug treatments can improve prognosis. If necessary, surgery also improves the patient's quality of life.

10. Tay-Sachs disease

Tay-Sachs disease is an inherited metabolic disorder in which, due to failures in lipid metabolism, the enzyme that breaks down them is not available. As a consequence of this, which occurs with only 3 months of life, fat accumulates in the baby's brain.

Fats have a toxic effect on the Central Nervous System, especially sensitive during childhood because of being still in development. The accumulation of fat in this system damages neurons, which results in problems with muscle control, seizures, weakness and, in the long term, blindness, paralysis and death.

For this medical condition to occur, two damaged genes must have been inherited from both parents, since it is an autosomal recessive disease, it is considered a very rare disorder. There is no cure, and the treatments currently available are merely palliative, which is why if it is known that there is a history relatives of people who have suffered this disease, a genetic analysis should be done to know if there is a probability of having a child with this disease condition.