Metabolic Disorders

February 7, 2017

Metabolic disorders are any of the diseases or disorders that disrupt normal metabolism – the process of converting food to energy on a cellular level. Thousands of enzymes participating in numerous interdependent metabolic pathways carry out this process. Metabolic diseases affect the ability of the cell to perform critical biochemical reactions that involve the processing or transport of proteins (amino acids), carbohydrates (sugars and starches), or lipids (fatty acids).

Disorders in metabolism can be inherited, in which case they are also known as inborn errors of metabolism, or they may be acquired during your lifetime. Many metabolic disorders exist, and they are common in the United States. For, instance, diabetes is metabolic disease that affects approximately 26 million Americans. The onset of symptoms usually occurs when the body’s metabolism comes under stress—for example, after prolonged fasting or during a febrile illness. For some metabolic disorders, it is possible to obtain prenatal diagnostic screening.

Metabolic disorder is quite common. Approximately 32% of the population in the U.S. has metabolic disorder. Around 25% of adults in Europe and Latin America are estimated to have the condition, and rates are rising in developing East Asian countries. Within the US, Mexican Americans have the highest prevalence of metabolic disorder. The prevalence of metabolic disorder increases with age, and about 40% of people over 60 are affected.

Risk Factors

A number of factors increase the risk of developing metabolic disorders. Not all people with risk factors will get metabolic disorders. Risk factors for metabolic disorders include –

  • Certain chronic medical conditions, such as lung or kidney disease (includes any type of kidney problem, such as kidney stones, kidney failure and kidney anomalies)
  • Family history of genetic metabolic disorder
  • HIV/AIDS

Types of Metabolic Disorders

Some types of Metabolic Disorders are –

  • Adrenoleukodystrophy (ALD) – This is a rare but fatal genetic disorder in which patients accumulate high levels of saturated, very-long-chain fatty acids in the brain and adrenal cortex, which develop because they cannot produce an enzyme that breaks down fatty acids. This leads to a breakdown of the myelin sheath, the membrane that protects the brain and spinal cord. This conditions also causes the adrenal glands to secrete cortisol, which regulates glucose metabolism, blood pressure and the release of insulin for blood pressure maintenance.
  • Alkaptonuria – Also called onchorosis, this is a rare metabolic disorder characterized by arthritis in adulthood and dark brown or black urine, which occurs when a patient cannot break down tyrosine, a type of amino acid, due to a defect in an enzyme that causes something called homogenistic acid to be released in the urine. Homogenistic acid turns brown when exposed to air. This condition is not life threatening, although lifelong treatment to manage systems is often required.
  • Cystinosis – This metabolic disorder is characterized by an abnormal accumulation of the amino acid cystine in the body, causing cystine to build up in the kidneys, eyes, muscles, pancreas and brain, eventually leading to tissue and organ damage.
  • DIDMOAD (Wolfram) syndrome – DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy and deafness) syndrome is an inherited neurodegenerative disease that takes place when the protein wolframin does not function properly, causing an inability to concentrate urine (diabetes insipidus), and inability to produce or properly use insulin (diabetes mellitus), blindness or deafness. Patients can also suffer from serious nervous system problems.
  • Glucose 6-phosphate-dehydrogenese deficiency – G6PD deficiency is an inherited enzyme deficiency in which patients has low levels of G6PD in their blood cells, causing the cells to die prematurely when the patient has an infection or is exposed to chemicals in food or medications.
  • Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) – HHH is a rare disorder in which patients suffer from poor coordination and learning disabilities due to a buildup of an amino acid called ornithine that prevents the removal of nitrogen waste from the body.
  • Inborn errors of urea synthesis – This metabolic disorder occurs when a series of enzyme reactions that remove nitrogen waste from the blood, called the urea cycle, is disrupted, leading to increased levels of ammonia in the blood and a condition called hyperammonemia, which leads to mental retardation, coma and death.
  • Kearns-Sayre syndrome – This is a rare neuromuscular disorder that occurs when there are mutated mitochondria inside a patient’s cells. This condition mostly affects the eyes.
  • Maple syrup urine disease (MSUD) – This metabolic disorder is caused by a deficiency of an enzyme needed to break down amino acids; these amino acids can build up to toxic levels in the body, and MSUD can cause brain and progressive nervous system damage.
  • McArdle’s disease – Also called glycogen storage disease, this is a rare muscular disease in which patients are unable to produce a protein called phosphorylase needed to produce the energy skeletal muscles require to exercise.
  • MELAS syndrome – MELAS (mitochondrial encephalopathy, lactic acidosis and stroke-like episodes) syndrome is a very form of dementia, which is fatal and has no cure.
  • Metabolic syndrome – Also called syndrome X, this condition is characterized by a patient having two or more of a group of conditions such as high blood pressure, high insulin levels, excess waist fat and high cholesterol. Patients with this condition are more likely to develop stroke, heart disease and diabetes.
  • Phenylketonuria (PKU) – Also called Folling’s disease, this potentially fatal condition occurs when patients do not have an enzyme needed to produce a protein called phenylalanine. People with this condition must follow a strict diet that does not contain phenylalanine, which means avoiding high-protein foods such as meat, cheese, milk or nuts.
  • Pyruvate carboxylase deficiency (hyperalaninemia) – Patients with this condition are born with low levels of the enzyme pyruvate carboxylase, which is needed to break down alkaline in the blood.
  • Subacute necrotizing encephalopathy – Also called Leigh’s disease, this fatal condition is caused by a missing enzyme called dehydrogenase, and is characterized by a degeneration of the brain and spin cord.
  • Tay-Sachs disease (TSD) – This condition progressively destroys the brain and nervous system, leading to blindness, paralysis and death. Symptoms of the most common type of TSD usually form when the baby is six months old, and patients typically die within a few years.
  • Trimethylaminuria – Patients with this condition excessively produce a protein called trimethylamine, given them offensive body odor that smells like rotting fish.

Causes

Metabolic disorders develop when normal metabolic processes are disturbed. Normally, food is broken down by the body into simpler components (proteins, fats and sugars) in a highly regulated manner. Metabolic disorders are defined by a breakdown in any one of the steps of this complex process. Disorders in metabolism can be inherited, in which case they are known as inborn errors of metabolism, or they may be acquired. They may also occur as complications of other serious diseases, such as liver or respiratory failure, cancer, end-stage chronic obstructive pulmonary disease (COPD, includes emphysema and chronic bronchitis), and HIV/AIDS.

Genetic Factor – There are numerous examples of inherited metabolic disorders, which can be classified based on the type of food-related building block that they affect, including amino acids (the building block for proteins), carbohydrates, and fatty acids (the building block for fats). Inherited causes of metabolic disorders include:

  • Amino acid disorders; examples include Tay-Sachs disease, phenylketonuria, tyrosinemia, maple syrup urine disease, and homocystinuria
  • Carbohydrate disorders; examples include diabetes insipidus, hereditary fructose intolerance, galactosemia, pyruvate metabolism disorders, von Gierke’s disease, McArdle disease, Pompe’s disease, and Forbes’ disease
  • Fatty acid oxidation defects; examples include Gaucher’s disease, Niemann-Pick disease, Fabry’s disease, and medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency

Other Factors – Metabolic disorders can be due to other factors, such as a combination of inherited and environmental factors. Other examples of conditions that can cause metabolic disorders include –

  • Alcohol abuse
  • Diabetes (chronic disease that affects your body’s ability to use sugar for energy)
  • Diuretic abuse
  • Gout (type of arthritis caused by a buildup of uric acid in the joints)
  • Ingestion of poison or toxins, including excessive aspirin, bicarbonate, alkali, ethylene glycol, or methanol
  • Kidney failure
  • Pneumonia, respiratory failure, or collapsed lung
  • Sepsis (life-threatening bacterial blood infection)

Symptoms

The symptoms of metabolic disorders vary widely depending on the metabolism problem present. Some symptoms of metabolic disorders include –

  • Lethargy
  • Poor appetite
  • Abdominal pain
  • Vomiting
  • Weight loss
  • Jaundice
  • Failure to gain weight or grow
  • Developmental delay
  • Seizures
  • Coma
  • Abnormal odor of urine, breath, sweat, or saliva

The symptoms may come on suddenly or progress slowly. Symptoms may be brought on by foods, medications, dehydration, minor illnesses, or other factors. Symptoms appear within a few weeks after birth in many conditions. Other inherited metabolic disorders may take years for symptoms to develop.

Metabolic disorders can present with a great diversity of signs and symptoms that mimic non-genetic disorders. Common presenting symptoms are –

  • Acute neonatal symptoms (described below)
  • Failure to thrive
  • CNS symptoms such as developmental delay, movement or psychiatric disorder or cerebral palsy
  • Sudden infant death syndrome (SIDS)
  • Episodic illness – anorexia, vomiting, lethargy, coma
  • Cardiomyopathy
  • Muscular – hypotonic, weakness, cramps
  • Gastrointestinal – anorexia, vomiting, diarrhoea, malabsorption
  • Liver disease
  • Ophthalmic abnormalities
  • Reye’s syndrome-like illness
  • Dysmorphic features
  • Metabolic – acidosis, hypoglycaemia

Treatment

Treatment for metabolic disorders begins with seeking medical care from your health care provider. The treatment approach for metabolic disorders depends on the specific disorder. Inborn errors of metabolism ( metabolic disorders) are often treated with nutritional counseling and support, periodic assessment, physical therapy, and other supportive care options. Acquired metabolic disorder treatment will include normalizing the metabolic balance by both reversing the cause and administering medications.

Treatment options for metabolic disorders – Multiple treatment options are available for inherited metabolic disorders. Examples include –

  • Bone marrow transplantation
  • Enzyme replacement therapy in selected patients
  • Gene therapy in selected patients
  • Medications to reduce symptoms, such as pain or low blood sugar
  • Mineral supplementation
  • Nutritional counseling
  • Physical therapy
  • Surgery to relieve pain or symptoms
  • Vitamin supplementation

Alternative Treatment

Chromium – Improves glucose tolerance and balances blood‐sugar levels.

Magnesium – Plays an important role in both the prevention and treatment of Metabolic Disorder and diabetes. It benefits these conditions by increasing the number and sensitivity of insulin receptors.

Gymnema sylvestre – An herb native to the tropical forests of southern and central India, it lowers blood sugar levels.

Alpha lipoic acid – Some researchers credit alpha‐lipoic acid with being the principal supplement for preventing and reversing Metabolic Disorder. The supplement earned this reputation by increasing the burning of glucose. The body needs alpha‐lipoic acid to produce energy; it plays a crucial role in the energy‐ producing structures in cells (mitochondria). The body actually makes enough alpha‐ lipoic acid for this basic function.

Vanadyl sulfate  – Vanadyl Sulfate is the most popular and common form of vanadium, an element in the body that is found in foods such as pepper, dill, radishes, eggs, vegetable oils, buckwheat, and oats.

Highpotency multivitamin/mineral supplement – This will supply many of the nutrients involved with blood sugar metabolism.

Biotin – Biotin is involved with proper glucose metabolism.

Essential Fatty Acids  – EFAs – especially omega‐3s – are vital to health and proper insulin function. Flaxseed or fish oil, combined with evening primrose oil is a good idea.

 

Reference –

http://www.healthgrades.com/conditions/metabolic-disorders–treatments

http://www.healthline.com/health/nutrition-metabolism-disorders#Types4

http://www.britannica.com/science/metabolic-disease/Disorders-of-lipid-metabolism

https://www.floridahospital.com/metabolic-disorders/treatments

http://www.medicinenet.com/metabolic_syndrome/page4.htm#what_is_the_treatment_for_metabolic_syndrome

http://www.webmd.com/a-to-z-guides/inherited-metabolic-disorder-types-and-treatments?page=3#1

http://www.mda.org/disease

http://www.biomedcentral.com/content/pdf/1741-7015-9-48.pdf

http://gep.wustl.edu/curriculum/course_materials_WU/introduction_to_genomics/bio3055/3055/projects/HPRT1/ch14d1.pdf

https://www.idf.org/webdata/docs/IDF_Meta_def_final.pdf