Metabolic Disorders

What are metabolic disorders?

Metabolic disorders are conditions of the metabolism. The body’s metabolism is what allows for food to be processed into energy. Food consists of carbohydrates, fats, and proteins, which are metabolized into sugars and acids to fuel the body. When this essential process is disrupted, it produces either too much or too little of what the body needs to continue functioning. Metabolic disorders are the result of a disrupted metabolism.

Metabolic disorders can take hundreds of different forms. Something as simple as a single mutated gene can cause them. Many metabolic disorders are inherited genetically, but environmental and lifestyle factors can also influence a patient’s risk for developing a metabolic disorder.

What causes metabolic disorders?

A wide range of factors can cause metabolic disorders. Genetics is often at play when a metabolic disorder is diagnosed. Most metabolic disorders are the result of a genetic mutation that is passed down, generation after generation. Other causes of metabolic disorders are a deficiency of a hormone or enzyme, having too much or too little of specific foods, or when some organs, like the pancreas or liver, become diseased and their functions are disrupted.

The causes of metabolic disorders are not limited to this list, for there are a number of other genetic, environmental, and lifestyle factors that can influence a patient’s metabolism. See below for a more comprehensive list of risk factors or groups for some metabolic disorders.

What are the different kinds of metabolic disorders?

There are hundreds of different kinds of metabolic disorders. This particular page highlights the symptoms and risk factors or groups for a few of the most common metabolic disorders, but this list is not exhaustive. The metabolic disorders discussed here are diabetes, sickle cell anemia, cystic fibrosis, hemochromatosis, Maple Syrup Urine Disease, and Gaucher disease.

• Diabetes occurs when the body is unable to produce insulin, or cannot use the insulin that is produced. Because insulin takes sugar from blood into cells, this process causes high blood sugar. The four types of diabetes are Type 1, Type 2, prediabetes, and gestational diabetes.
• Sickle cell anemia (also called sickle cell disease) is a red blood cell disease. This condition causes misshapen red blood cells. The cells’ usual shape is a disc, but sickle cell anemia causes the cells to be shaped like sickles. A sickle shape makes it hard for the red blood cells to move around, and blood ultimately cannot move as easily through the body. There are several types of sickle cell anemia.
• Cystic fibrosis damages the cells that produce mucus, sweat, and digestive enzymes. These fluids, usually thin, become thick and difficult to move, which can cause respiratory and digestive issues.
• Hemochromatosis occurs when the body has an excess of iron. There is no way for the body to get rid of the iron it does not need, so the iron is stored throughout the body, particularly in the pancreas, heart, and liver.
• Maple Syrup Urine Disease keeps the body from breaking down some kinds of amino acids due to an absence of the BCKDC (branched-chain alpha-keto acid dehydrogenase complex) enzyme. Untreated, this metabolic disorder can cause the patient to develop severe physical and neurological issues.
• Gaucher Disease is a lack of the glucocerebrosidase enzyme, which causes an excess of certain fatty substances to build up in the liver, lungs, bones, spleen, and, in severe cases, the brain.

What are common symptoms of metabolic disorders?

Each metabolic disorder attacks a function, or several, of the body. The metabolic disorders listed here have some overlapping symptoms but tend to present in different ways. Since this is not an exhaustive list of metabolic disorders, it will not cover all possible symptoms. Please see a doctor for the development of any abnormal symptoms.

• Symptoms of diabetes include extreme fatigue, increased hunger or thirst, weight loss, frequent urination, blurry vision, and sores that will not heal.
• Symptoms of sickle cell anemia include extreme fatigue, urinary incontinence, jaundice, swelling or pain in the hands or feet, increased infections, and pain in the arms, back, legs, or chest.
• Symptoms of cystic fibrosis include respiratory problems, like wheezing, persistent coughing, shortness of breath, stuffy nose or sinuses, and lung infections, as well as digestive problems, like nausea, constipation, unusual stool, loss of appetite, and a swollen abdomen.
• Symptoms of hemochromatosis include extreme fatigue, weight loss, joint pain, abdominal pain, decreased sex drive, and bronze or gray skin tint.
• Symptoms of Maple Syrup Urine Disease include extreme fatigue, weight loss, weak sucking ability, disrupted sleep, hypertonia and hypotonia, and a maple sugar odor in urine, earwax, and sweat.
• Symptoms of Gaucher Disease include extreme fatigue, yellow spots in the eyes, difficulty with eye movement, an enlarged spleen or liver, and lung issues.

Are there any risk factors or groups for metabolic disorders?

• Diabetes risk factors or groups depend on the type of diabetes. Type 1 diabetes is typically inherited genetically. Risk factors and groups for Type 2 diabetes include Alaska Natives, African Americans or Black people, Hispanic people or Latino Americans, Pacific Islanders, Native Americans, or Asian Americans, obesity, being 45 years or older, lack of physical activity, and if someone has had either gestational diabetes or prediabetes.
• Sickle cell anemia risk factors or groups include being Black, having endemic malaria, and people whose parents both carry the sickle cell trait.
• Cystic fibrosis risk factors or groups include people of northern European descent and people who have a family history of cystic fibrosis.
• Hemochromatosis risk factors or groups include alcohol dependency, family history of heart disease, liver disease, or diabetes, iron or Vitamin C supplements, and frequent blood transfusions.
• Maple Syrup Urine Disease risk factors or groups include whether or not the patient’s parents are both carriers for the disease.
• Gaucher Disease risk factors or groups include Eastern or Central European Jewish people (Ashkenazi).

What are common treatments for metabolic disorders?

Treatments for metabolic disorders are as varied as the disorders themselves. Not all metabolic disorders target the same bodily functions, so treatments are created to target the specific functions that have been disrupted.

• Type 1 diabetes is treated using insulin. Type 2 diabetes can be managed through diet and exercise, but there are several drugs available to treat this disorder if diet and exercise do not work.
• Sickle cell anemia is treated using blood transfusions, immunizations, rehydration, supplemental oxygen, and the treatment of underlying infections.
• Cystic fibrosis is treated using medications (antibiotics, mucus-thinning medications, bronchodilators, nonsteroidal anti-inflammatory drugs, and cystic fibrosis transmembrane conductance regulator modulators), surgeries (bowel surgery, double lung transplant, and feeding tube), chest physical therapy, and home care.
• Hemochromatosis is treated using phlebotomy and chelation.
• Maple Syrup Urine Disease is treated using dietary restriction of branched-chain amino acids (BCAA), which can also be administered intravenously.
• Gaucher disease is treated using some types of medication and enzyme replacement therapy.

When should a person see a doctor for metabolic disorders?

If a patient has family history of a specific metabolic disorder, or many, it is worth having a conversation with a doctor to see what testing is available. A genetic counselor can sometimes help parents determine their unborn child’s risk of developing a metabolic disorder, depending on which disorder is being tested. In fact, some metabolic disorders are detected during newborn screening.

However, for metabolic disorders that develop later in life, a patient should see a doctor as soon as abnormal symptoms develop. Doctors are integral to a successful, sometimes life-long treatment plan.

What is the outlook for people living with metabolic disorders?

A patient’s outlook varies greatly once diagnosed with a metabolic disorder. Some cases are milder, while others will cause frequent, severe disruptions to daily life. Milder metabolic disorders can often be managed through a regulated diet, exercise, and some medication. More severe cases can cause patients to have lifelong pain, and can progress into severe organ damage, or death.