My Research: Hypoglycemia

From the National Diabetes Information Clearing House

Description: Hypoglycemia, also called low blood sugar, occurs when your blood glucose (blood sugar) level drops too low to provide enough energy for your body’s activities. In adults or children older than 10 years, hypoglycemia is uncommon except as a side effect of diabetes treatment, but it can result from other medications or diseases, hormone or enzyme deficiencies, or tumors.

Glucose, a form of sugar, is an important fuel for your body. Carbohydrates are the main dietary sources of glucose. Rice, potatoes, bread, tortillas, cereal, milk, fruit, and sweets are all carbohydrate-rich foods.

After a meal, glucose molecules are absorbed into your bloodstream and carried to the cells, where they are used for energy. Insulin, a hormone produced by your pancreas, helps glucose enter cells. If you take in more glucose than your body needs at the time, your body stores the extra glucose in your liver and muscles in a form called glycogen. Your body can use the stored glucose whenever it is needed for energy between meals. Extra glucose can also be converted to fat and stored in fat cells.

When blood glucose begins to fall, glucagon, another hormone produced by the pancreas, signals the liver to break down glycogen and release glucose, causing blood glucose levels to rise toward a normal level. If you have diabetes, this glucagon response to hypoglycemia may be impaired, making it harder for your glucose levels to return to the normal range.

Symptoms: Symptoms of hypoglycemia include

• hunger
• nervousness and shakiness
• perspiration
• dizziness or light-headedness
• sleepiness
• confusion
• difficulty speaking
• feeling anxious or weak

Hypoglycemia can also happen while you are sleeping. You might

• cry out or have nightmares
• find that your pajamas or sheets are damp from perspiration
• feel tired, irritable, or confused when you wake up

Two Types:  Two types of hypoglycemia can occur in people who do not have diabetes: reactive (postprandial, or after meals) and fasting (postabsorptive). Reactive hypoglycemia is not usually related to any underlying disease; fasting hypoglycemia often is.

[As I have fasting hypoglycemia, this post focuses only on that type]

Fasting Hypoglycemia

Diagnosis
Fasting hypoglycemia is diagnosed from a blood sample that shows a blood glucose level of less than 50 mg/dL after an overnight fast, between meals, or after exercise.

Causes and Treatment
Causes include certain medications, alcohol, critical illnesses, hormonal deficiencies, some kinds of tumors, and certain conditions occurring in infancy and childhood.

Medications
Medications, including some used to treat diabetes, are the most common cause of hypoglycemia. Other medications that can cause hypoglycemia include

• salicylates, including aspirin, when taken in large doses
• sulfa medicines, which are used to treat infections
• pentamidine, which treats a very serious kind of pneumonia
• quinine, which is used to treat malaria

If using any of these medications causes your blood glucose to drop, your doctor may advise you to stop using the drug or change the dosage.

Alcohol
Drinking, especially binge drinking, can cause hypoglycemia because your body’s breakdown of alcohol interferes with your liver’s efforts to raise blood glucose. Hypoglycemia caused by excessive drinking can be very serious and even fatal.

Critical Illnesses
Some illnesses that affect the liver, heart, or kidneys can cause hypoglycemia. Sepsis (overwhelming infection) and starvation are other causes of hypoglycemia. In these cases, treatment targets the underlying cause.

Hormonal Deficiencies
Hormonal deficiencies may cause hypoglycemia in very young children, but usually not in adults. Shortages of cortisol, growth hormone, glucagon, or epinephrine can lead to fasting hypoglycemia. Laboratory tests for hormone levels will determine a diagnosis and treatment. Hormone replacement therapy may be advised.

Tumors
Insulinomas, insulin-producing tumors, can cause hypoglycemia by raising your insulin levels too high in relation to your blood glucose level. These tumors are very rare and do not normally spread to other parts of the body. Laboratory tests can pinpoint the exact cause. Treatment involves both short-term steps to correct the hypoglycemia and medical or surgical measures to remove the tumor.

Conditions Occurring in Infancy and Childhood

Children rarely develop hypoglycemia. If they do, causes may include

• Brief intolerance to fasting, often in conjunction with an illness that disturbs regular eating patterns. Children usually outgrow this tendency by age 10.
• Hyperinsulinism, which is the excessive production of insulin. This condition can result in transient neonatal hypoglycemia, which is common in infants of mothers with diabetes. Persistent hyperinsulinism in infants or children is a complex disorder that requires prompt evaluation and treatment by a specialist.
• Enzyme deficiencies that affect carbohydrate metabolism. These deficiencies can interfere with the body’s ability to process natural sugars, such as fructose and galactose, glycogen, or other metabolites.
• Hormonal deficiencies such as lack of pituitary or adrenal hormones.