5.1. Explain causes of metabolic disorders

This guide will help you answer 5.1. Explain causes of metabolic disorders.

Metabolic disorders involve problems with the way the body uses or converts food into energy. This process, known as metabolism, is essential for maintaining life. Such disorders can lead to various symptoms and complications, often affecting growth, energy levels, or organ function. Understanding the causes is critical to managing and preventing these conditions effectively.

Genetic Factors

Genetics is one of the leading causes of metabolic disorders. The process of metabolism relies on enzymes, which are proteins that speed up chemical reactions in the body. These enzymes are created based on instructions found in genes. If a gene carries a mutation (an error in its code), the enzyme it produces might not work properly or might not be produced at all. This can lead to a metabolic disorder.

Examples of inherited metabolic disorders include:

• Phenylketonuria (PKU): Caused by a gene mutation that affects the body’s ability to break down an amino acid called phenylalanine.
• Glycogen storage diseases: Occur when the body cannot properly store or use glycogen, a form of sugar stored for energy.
• Maple syrup urine disease: Caused by the inability to break down certain proteins.

People with a family history of these disorders are more likely to inherit them.

Hormonal Imbalances

Hormones play a crucial role in regulating metabolism. For instance, the thyroid gland produces hormones that control how quickly the body burns calories and uses energy. If there’s too much or too little of a hormone, it can disrupt metabolic processes.

Examples of metabolic disorders linked to hormonal imbalances include:

• Hyperthyroidism: Overactivity of the thyroid gland leads to excessive energy use, weight loss, and symptoms such as sweating and a racing heart.
• Hypothyroidism: Underactivity of the thyroid gland results in sluggish energy metabolism, causing fatigue and weight gain.
• Cushing’s syndrome: Caused by the overproduction of cortisol, a hormone that affects metabolism and can lead to fat accumulation and high blood sugar.

Hormonal imbalances can arise from autoimmune diseases, tumours, or other conditions affecting hormone-producing glands.

Dietary Deficiencies or Excess

Diet plays a significant role in metabolic health. A lack of key nutrients or overconsumption of harmful substances can cause metabolic disorders. For example:

• Vitamin or mineral deficiencies: Essential vitamins and minerals act as cofactors that help enzymes work. A deficiency in these can impair metabolic processes. For instance, a lack of vitamin D may influence calcium metabolism, increasing the risk of bone disorders.
• High sugar or fat intake: Over time, a poor diet can lead to insulin resistance and diabetes, a metabolic disorder where the body struggles to control blood sugar levels.

Both undernutrition and overnutrition can have long-term impacts on metabolism.

Infections

Certain infections can cause or worsen metabolic disorders. Some viruses and bacteria interfere with the function of organs involved in metabolism, like the liver or pancreas.

• Hepatitis viruses: These viruses can damage the liver, an organ essential for fat, protein, and carbohydrate metabolism.
• Pancreatitis: Infections or other factors that inflame the pancreas can disrupt its ability to produce insulin, leading to metabolic issues like diabetes.

Infections can act as both a trigger and a long-term disruptor of metabolism.

Medications and Toxins

Drugs and toxic substances can interfere with metabolism by altering organ function or enzyme activity. Repeated exposure or improper use of certain substances increases the risk of metabolic disorders.

• Corticosteroids: Long-term use can contribute to conditions like diabetes by increasing blood sugar levels.
• Alcohol: Excessive drinking damages the liver, leading to issues such as fatty liver disease, which disrupts metabolism.
• Environmental toxins: Chemicals such as pesticides or heavy metals can interfere with enzymes and organ health, contributing to metabolic problems.

People working in industries involving chemicals should take precautions to minimise exposure.

Lifestyle Factors

Lifestyle choices often influence metabolic health over time. Smoking, lack of exercise, and poor sleep patterns are common contributors.

• Smoking: Reduces oxygen supply to cells, affecting their ability to use energy efficiently. Long-term smoking is linked to diseases like chronic obstructive pulmonary disease (COPD), which indirectly affects metabolism.
• Physical inactivity: Lowers the body’s overall energy use and can lead to obesity and insulin resistance.
• Poor sleep: Disrupts hormonal regulation of appetite and energy use, increasing the risk of metabolic issues like obesity.

Making healthy lifestyle changes can reduce the risk of developing these disorders.

Autoimmune Conditions

Autoimmune diseases occur when the immune system mistakenly attacks normal tissues. This can cause damage to organs critical to metabolism, especially the thyroid and pancreas.

Examples include:

• Type 1 diabetes: The immune system damages the pancreas, reducing its ability to produce insulin, a hormone required for blood sugar management.
• Hashimoto’s thyroiditis: An autoimmune attack on the thyroid gland, leading to hypothyroidism and its associated metabolic disturbances.

Such conditions often require long-term management.

Birth-Related Causes

Metabolic disorders can sometimes occur due to complications during pregnancy or birth. These issues may affect the development of organs or systems involved in metabolism.

Examples include:

• Maternal malnutrition during pregnancy, which can impair the development of metabolic pathways in the baby.
• Premature birth, which can lead to underdeveloped organs like the liver or pancreas, increasing metabolic risks later on.

Preventative care during pregnancy reduces these risks significantly.

Ageing

Ageing naturally reduces the efficiency of metabolic processes. This can increase vulnerability to disorders over time.

• Decreased muscle mass: With age, the body loses muscle, which lowers the resting metabolic rate.
• Changes in enzyme activity: Enzymes may become less effective, slowing metabolic reactions.
• Organ function decline: For instance, ageing reduces the liver’s ability to detoxify and process nutrients effectively.

Maintaining an active lifestyle can help counteract some of these effects.

Trauma and Surgery

Serious trauma or surgery can disrupt metabolism temporarily or permanently. When the body undergoes major stress, such as during recovery from an injury, energy demands increase, but the body’s ability to meet them decreases.

Trauma can damage organs, leading to long-term metabolic issues. For example, liver damage affects the body’s ability to process toxins and produce proteins.

Final Thoughts

Metabolic disorders arise from a variety of causes, including genetic mutations, lifestyle choices, and external triggers like infections and toxins. Addressing these underlying factors early can prevent or minimise complications. Healthcare workers should understand these causes to provide appropriate support and advice to individuals affected by these conditions.