Metabolic Myopathy

Metabolic Myopathy
Body Parts: Whole Body
Medical Subjects: Nervous System

What Is Metabolic Myopathy?

Metabolic myopathy refers to muscle diseases caused by metabolic factors, including primary metabolic myopathy and secondary metabolic myopathy. The latter refers to muscle disease secondary to thyroid, parathyroid, pituitary, adrenal disease or other metabolic diseases.

Symptoms can manifest as gradually or rapidly progressing muscle weakness, myalgia, and muscle atrophy. Most of the primary patients have a family genetic history, and the secondary ones are often accompanied by symptoms of other metabolic diseases.

Are there many people with metabolic myopathy?

Primary metabolic myopathy is a rare clinical disease, and the incidence of secondary metabolic diseases is slightly higher.

Are metabolic myopathy and muscular dystrophy the same disease?


The former is a muscle disease caused by metabolic factors related to various etiologies, and the latter is a muscle degeneration disease caused by genetic factors. The pathological changes of muscles in the two types of diseases are different, and the mechanism of occurrence is also different.


What Is The Cause Of Metabolic Myopathy?

The energy required for muscle contraction is provided by ATP hydrolysis. The energy for short-lived muscle activity comes from glycogen reserves, and creatine phosphorylase participates in the glycogen metabolism process. Fatty acids from adipose tissue and intracellular lipid storage are another major source of energy, and muscle dysfunction indicates energy exhaustion. The cytochrome oxidation process plays an important role in both aerobic and anaerobic metabolism of muscles.

Muscle contraction and maintenance of endurance depend on the continuous supply of glycogen, glucose, fatty acids and metabolic enzymes. Abnormal functions in any link of the storage, decomposition and utilization of these biochemical substances may lead to metabolic myopathy.

What are the causes of metabolic myopathy?

  • Primary metabolic myopathy is mainly due to abnormal muscle metabolism caused by hereditary factors. The common ones include glycogen storage myopathy, dyslipidemia myopathy and mitochondrial myopathy.
  • Secondary metabolic myopathy refers to abnormal muscle metabolism secondary to other diseases, common including thyroid myopathy, corticosteroid myopathy, adrenal insufficiency myasthenia, parathyroid myopathy, pituitary disease Muscle weakness.

What Are The Manifestations Of Metabolic Myopathy?

According to the cause and severity of the disease, the manifestations of metabolic diseases are different. Generally speaking, they include the following aspects:

  • Muscle symptoms: It is manifested as muscle weakness in different degrees and parts, easy to fatigue, gradually progressive muscle atrophy, some cases may have myalgia, some may have muscle volume increase, and a few cases may have "flesh jumping" or "cramping" sensation, serious Sometimes there may be weakness of the respiratory muscles, which can cause breathlessness and fatigue, and even respiratory failure.
  • Primary metabolic myopathy is a muscle disease caused by dysfunction of muscle metabolic enzymes, abnormal glycogen and lipid metabolism, or damage to mitochondria resulting in energy supply obstacles, and most of them are hereditary. Infants and young children often have enlarged hearts, enlarged livers, organ failure, abnormal development, and decreased intelligence. The above symptoms are relatively mild in adults with onset.
  • Patients with secondary metabolic myopathy also have symptoms of related metabolic diseases. For example, those with hyperthyroidism may have symptoms such as exophthalmos, excitement, increased heart rate, hyperappetite, hyperhidrosis, weight loss and other symptoms.

What are the serious consequences of metabolic myopathy?

Severe metabolic myopathy can involve respiratory muscles and cause respiratory failure. Certain metabolic myopathy can also cause liver failure, kidney failure, and heart failure. Infant-onset hereditary metabolic myopathy has a short survival time.


How To Judge Metabolic Myopathy?

Metabolic myopathy has many causes, and sometimes it is difficult to diagnose. Clinicians determine the cause of the cause based on the patient's symptoms and signs, combined with laboratory tests, neuroelectrophysiology, muscle biopsy, and genetic testing, and other diagnoses need to be ruled out.

What tests should be done for suspicious patients with metabolic myopathy? Why do these checks?

For patients who are suspected of having metabolic myopathy, it is necessary to conduct targeted and comprehensive examinations based on the medical history and physical signs to clarify the cause. The main examination items include:

  • Hematological examination (including liver and kidney function, thyroid function, parathyroid function, hormone determination, lactic acid, muscle enzymology): clarify whether there are secondary factors, and assist in the diagnosis of mitochondrial myopathy.
  • Urine examination (including urine routine, metabolites, myoglobin, etc.): to help clarify the cause.
  • Neurophysiological examinations (including electromyography and others): It is confirmed that the myasthenia is myogenic damage, and the neurogenic myasthenia is excluded.
  • Muscle biopsy: The pathological examination of muscles is valuable for confirming the diagnosis of metabolic myopathy, and characteristic metabolic pathological changes of muscles can be found.
  • Genetic testing: It has diagnostic value for suspected hereditary causes, and can also help genetic counseling.

What conditions need to be differentiated from metabolic myopathy?

Metabolic myopathy needs to be differentiated from other myopathy and peripheral nerve diseases, including inflammatory myopathy, muscular dystrophy, toxic myopathy, multiple peripheral nerve diseases, motor neuron diseases, etc.


Can Metabolic Myopathy Be Prevented?

Actively diagnose and treat related diseases that easily cause metabolic myopathy, which has a positive effect on preventing secondary metabolic myopathy. However, because most of the primary metabolic myopathy is a genetic disease, there is no way to prevent it.


How Is Metabolic Myopathy Treated?

Cause treatment

For secondary metabolic myopathy, the primary disease is mainly treated. Most of the primary metabolic myopathy has no specific treatment, and some people who lack sugar, lipids, carnitine and other components can be given special supplementary or alternative treatments.

Symptomatic support

Reduce the amount of exercise and physical activity. If symptoms of breathing effort occur, effective respiratory support can help prolong the life of the patient, and patients with respiratory failure should be actively treated symptomatically.


What Should Patients With Metabolic Myopathy Pay Attention To In Life?

Patients with metabolic myopathy should reduce strenuous exercise and avoid overwork and cold. In the event of breathing effort, etc., it needs to be supported by a ventilator.

What should patients with metabolic myopathy pay attention to in their diet?

The dietary requirements of patients with metabolic myopathy are different according to the etiology, and it is impossible to generalize. For example, patients with type II acid maltase deficiency in glycogen storage myopathy need to limit carbohydrate intake, and patients with type V muscle phosphorylase deficiency may benefit from taking high sugar or oral fructose before exercise. It is necessary to consult a specialist according to the cause of the disease and follow the doctor's advice.

Does metabolic myopathy need to be reviewed? How to review?

If necessary, the cause is generally reviewed.

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