Beriberi Health Article

Definition

Beriberi is a condition caused by severe prolonged deficiency of vitamin B1 (also known as thiamine). Beriberi refers to a constellation of heart, gastrointestinal, and nervous system problems from thiamine deficiency.

Description

Thiamine is found in a variety of foods, particularly whole grains, legumes, and pork. Thiamine serves as a coenzyme in the chemical pathway responsible for the metabolism of carbohydrates. Thiamine deficiency interferes with the metabolism of glucose and the production of energy.

Four major types of beriberi exist: wet beriberi, which affects primarily the cardiovascular system; dry beriberi, which affects primarily the nervous system; shoshin, which is a rapidly evolving and frequently fatal form of cardiovascular beriberi; and infantile beriberi, which tends to strike babies between the ages of one and four months who are breastfed by mothers who are severely thiamine deficient.

Demographics

Because so many foods in the United States and other western countries are vitamin enriched, beriberi is extremely rare. In developed countries, beriberi is primarily a complication of malnutrition secondary to alcoholism or gastrointestinal disorders. Because alcoholism affects more males than females, rates of beriberi in developed countries are higher among males. The syndrome of symptoms caused by thiamine deficiency in alcoholism is called Wernicke-Korsakoff syndrome.

In developing countries, where diets are more limited, beriberi is endemic. In some areas of Asia, people subsist on polished rice, in which the outer, more nutritious husk is removed. The rates of beriberi in these areas are quite high. In certain parts of Indonesia, the prevalence of beriberi among low-income families is as high as 66%. The majority of patients with beriberi are infants (ages 1–4 months) and adults.

Causes and symptoms

Symptoms of beriberi are caused by abnormal metabolism of carbohydrates throughout the body, resulting in a decreased production of energy, and particular injury to the heart muscle and the nervous system.

Symptoms of dry beriberi include:

• numbness, tingling, burning pain in extremities
• pain and cramping in the leg muscles
• difficulty with speech
• problems walking
• disturbed sense of balance

Symptoms of wet beriberi include:

• fast heart rate
• swollen feet and legs
• enlarged heart
• enlarged, tender liver
• shortness of breath
• congestion in the lungs

Symptoms of shoshin beriberi are the same as those of wet beriberi, but the onset is sudden, the progression is rapid, and the risk of death is very high.

Symptoms of infantile beriberi include:

• restlessness
• difficulty sleeping
• diarrhea
• swollen arms and legs
• muscle wasting in arms and legs
• silent cry
• heart failure

Symptoms may coexist with other disorders due to thiamine deficiency such as Wernicke-Korsakoff encephalopathy. In such cases, confusion, memory loss, difficulty with eye movements, and even coma may occur.

Diagnosis

The first step to diagnosis includes taking a careful history to uncover a possible underlying cause for thiamine deficiency. Physical examination will demonstrate some of the expected signs of beriberi, such as swelling, decreased reflexes, decreased sensation, problems with walking or balance, etc.

Laboratory testing to demonstrate thiamine deficiency includes measurements of thiamine in the blood; tests of the activity of thiamine in whole blood or red blood cells (called transketolase activity), both before and after the administration of thiamine; measurements of the chemicals lactate and pyruvate in the blood (these will be increased in beriberi); and measurements of the amount of thiamine passed into the urine (this will be decreased in beriberi).

In some cases, the diagnosis of beriberi is made only after thiamine supplementation results in a resolution of the patient's symptoms.

Treatment team

Depending on how a patient enters the health care system, an emergency room physician, internal medicine physician, family practitioner, neurologist, gastroenterologist, or cardiologist may treat a patient for beriberi. A nutritionist should be consulted to develop a nutritional plan. If alcoholism is an underlying problem, the patient may need to enter an alcohol rehabilitation program. Physical therapy may help patients recover from the neurological complications of beriberi.

Treatment

When a patient has serious symptoms of thiamine deficiency, supplementation is usually started by giving thiamine through an IV or by intramuscular shots. Because magnesium is required for the proper functioning of thiamine, magnesium is usually administered through injections as well. After several days of this therapy, a multivitamin containing 5–10 times the usually recommended daily allowance of all the water-soluble vitamins, including thiamine, should be given for several weeks. Ultimately, the patient will be advised to follow a lifelong regimen of nutritious eating, with the regular diet supplying 1–2 times the recommended daily allowance of the water-soluble vitamins, including thiamine.

Recovery and rehabilitation

Recovery from the cardiovascular effects of beriberi is nearly always complete. Some of the neurological problems, however, may remain even after thiamine supplementation has been accomplished.