Carbohydrate Metabolism Defects - Conditions and Treatments

Introduction:

Food consists of carbohydrates, proteins, and fats. Carbohydrates are sugars that are simple and complex. The carbohydrates are rich in fiber, sugars, and starches in the body and are converted into glucose that provides energy for functioning. The chemicals in the digestive system break down the food into sugars and acids. The carbohydrates are broken down by glucose by the digestive system. The amount of carbohydrates consumed affects the blood glucose level in the body. Total carbohydrates refer to the combinations of all three types of carbohydrates: sugars, starches, and fiber. Metabolism is a process by which the body makes energy from food.

What Are Carbohydrate Metabolic Disorders?

The carbohydrate metabolism is:

• Carbohydrate metabolism disorders are metabolic disorders with a deficiency of enzymes that breaks carbohydrates down into glucose. It occurs when there is a defect in the formation of glucose from the sugars. The disorders of carbohydrates are hereditary (inherited) or metabolic.

• The parents pass the defective gene to children with congenital disorders. Inherited carbohydrate metabolism disorders with genetic defects lead to a lack of certain metabolic enzymes in sugar metabolism.

• Fructose and glucose are two simple sugars that make sucrose. Glucose and galactose make lactose.

• Enzymes break down sucrose and lactose before the body absorbs and uses them. If the enzyme needed to break down sugar goes missing, the sugar accumulates in the body, which causes metabolic disorders.

• The disorders of carbohydrate mechanisms are galactosemia, hereditary fructose intolerance, glycogen storage diseases, and pyruvate metabolism disorders.

What Are the Medical Conditions That Affect the Carbohydrate Metabolism?

The medical conditions that affect the metabolism of carbohydrates are:

• Galactosemia.

• Fructose malabsorption.

• Glycogen storage diseases.

• Pyruvate metabolic disorders.

What Is Galactosemia?

Galactosemia is a metabolic disorder in which the body cannot metabolize galactose. The inherited disorder has a defective enzyme that prevents from breaking down the sugar into galactose which builds up to toxic levels in the blood. Breast milk comprises good things such as antibodies, hormones, and essential nutrients that protect babies from diseases. Galactose is present in breast milk and many baby formulas.

• Some babies are born with galactosemia, in which the babies are unable to metabolize galactose into energy.

• Once the disorder is diagnosed, it is easy to treat with a lactose-restricted diet. If left untreated, it can be life-threatening.

• Galactosemia is a hereditary disorder where the genes that produce the enzyme to break down galactose into glucose are defective or missing. Without these genes, the enzymes cannot do their function.

• Due to this, galactose starts to build up in the blood of the babies. The symptoms include vomiting, jaundice, diarrhea, and severe weight loss in babies. They can have liver and kidney damage. The three types of galactosemia are-

• Classic (type I).

• Galactokinase deficiency (type II).

• Galactose epimerase deficiency (type III).

What Is Fructose Malabsorption?

Fructose is a monosaccharide that is simple sugar from vegetables and fruits. It is available in honey, nectar, and some processed foods with added sugars. They are fermentable carbohydrates.

• Fructose malabsorption is also called dietary fructose intolerance. In this disorder, the intestine cells cannot break down fructose efficiently.

• Fructose malabsorption is associated with fructose intolerance. Hereditary fructose intolerance is a rare genetic condition where the body does not make the enzyme needed to break fructose.

• In the intestine cells (enterocytes), fructose carriers are present. These carriers are responsible for ensuring that fructose is directed to the site where it is needed. If the intestinal cells are deficient, the fructose can build up in the large intestine and causes gut problems.

• Fructose malabsorption is due to processed sugars, stress, and an imbalance of good and bad bacteria in the gut. The symptoms include abdominal pain, nausea, diarrhea, and vomiting. Elimination of fructose-rich food will help a lot to avoid this condition.

What Are Pyruvate Metabolic Disorders?

Pyruvates are formed in the metabolism of proteins and carbohydrates. The disorder is due to a lack of enzymes required to process pyruvate.

• Pyruvate metabolic disorders are inherited conditions that cause lactic acid to accumulate in the blood. The pyruvate metabolism defects can limit a cell’s ability to produce energy and cause the buildup of lactic acid waste products.

• Many enzymes are involved in pyruvate metabolism. A hereditary deficiency in these enzymes results in various disorders depending on which enzyme is deficient. Pyruvate dehydrogenase and pyruvate carboxylase deficiency are disorders of pyruvate metabolism.

• It is caused due to lack of metabolism of pyruvate. There is a build-up of lactic acid because of this. The deficiency of the enzymes involved in pyruvate metabolism leads to the disease. The condition's symptoms include muscle weakness, seizures, and coordination problems. The lack of the enzyme pyruvate carboxylase causes a rare condition that blocks glucose production from pyruvate in the body. Newborns with this condition have brain malformations.

• The lack of the pyruvate decarboxylase enzyme causes a rare disease that interferes with glucose production from pyruvate in the body. As a result, lactic acid and ketones build up in the blood.

What Are Glycogen Storage Diseases?

Glycogen is a carbohydrate made up of many glucose molecules that are linked together. When not used, glucose is stored in glycogen form in the liver and muscles.

• When the body requires energy, the glycogen is converted into glucose again and released to the tissues where the energy is required.

• If the enzyme necessary to convert glucose into glycogen and the enzymes responsible for breaking it into glucose are defective, they need to be fixed. Carbohydrate metabolism disorders include glycogen storage diseases that occur when a defect or lack of enzymes is involved in glycogen metabolism.

• The enzymes break down glycogen into glucose. The symptoms include weakness, sweating, kidney stones, confusion, low blood sugar, and stunted growth.

What Is the Treatment for Carbohydrate Metabolism Disorders?

The treatment includes supplements, special diets, and medicines. There is no permanent cure, but treatments can help improve the symptoms. Eliminating fructose-rich diets such as certain fruits, pears, cherries, apples, honey, ice cream, candy, and cookies is a good way to treat the disorder. The only way to treat galactosemia is to eliminate the galactose from the diet, like avoiding dairy products. Dairy products can be replaced with vitamin D and calcium to compensate for the lack of dairy products. For bone density, it can be replaced with vitamin D and calcium. The treatment consists of regular doses of nutrition supplements. Small meals low in sugar help keep blood sugar levels, preventing glycogen storage in the liver.

Conclusion:

The treatment is limited for inherited disorders and varies depending on the condition. There are enzymes and chemical replacements to help metabolism return to normal function. Other treatments involve the removal of toxic metabolic byproducts.