Hyperinsulinism

A condition characterized by excessive insulin levels in the blood

Chemical structure of insulin

Hyperinsulinism is a condition characterized by an excess of insulin in the bloodstream. This condition can lead to various metabolic disturbances, primarily affecting the regulation of blood glucose levels. Hyperinsulinism can be caused by several factors, including insulinoma, congenital hyperinsulinism, and reactive hypoglycemia.

Pathophysiology

Hyperinsulinism occurs when there is an overproduction of insulin by the pancreas, or when the body's tissues are overly sensitive to insulin. Insulin is a hormone produced by the beta cells of the islets of Langerhans in the pancreas. It plays a crucial role in regulating blood glucose levels by facilitating the uptake of glucose into cells for energy production or storage as glycogen.

In hyperinsulinism, the excessive insulin levels cause blood glucose to be taken up by cells at a higher rate than normal, leading to hypoglycemia, or low blood sugar levels. This can result in symptoms such as dizziness, sweating, confusion, and in severe cases, seizures or coma.

Causes

There are several causes of hyperinsulinism, including:

• Insulinoma: A rare tumor of the pancreas that secretes insulin.
• Congenital hyperinsulinism: A genetic disorder where the beta cells produce too much insulin.
• Reactive hypoglycemia: A condition where insulin is overproduced in response to a meal, leading to low blood sugar levels.
• Medications: Certain medications, such as sulfonylureas, can cause increased insulin production.

Diagnosis

The diagnosis of hyperinsulinism involves measuring blood insulin and glucose levels. A fasting test may be conducted to observe the body's insulin response when no food is consumed. Imaging studies, such as CT scan or MRI, may be used to identify insulinomas or other pancreatic abnormalities.

Treatment

Treatment of hyperinsulinism depends on the underlying cause. Options include:

• Surgical removal: In cases of insulinoma, surgical removal of the tumor is often necessary.
• Dietary management: Frequent small meals and a diet low in simple carbohydrates can help manage symptoms.
• Medications: Drugs such as diazoxide or octreotide may be used to reduce insulin secretion.

Prognosis

The prognosis for individuals with hyperinsulinism varies depending on the cause and the effectiveness of treatment. With appropriate management, many individuals can lead normal lives, although ongoing monitoring and treatment may be necessary.

Related pages

• Insulin
• Hypoglycemia
• Pancreas
• Endocrinology