Congenital Hyperinsulinism

Congenital HI is the most common cause of recurrent hypoglycemia in neonates and infants. The incidence of congenital HI is estimated at 1 in 25,000 to 1 in 50,000 live births throughout the world, but is as high as 1 in 2500 live births in certain populations where the gene pool is limited. Typically, congenital HI presents in the first month of life with non-specific signs and symptoms consistent with hypoglycemia. Over time, recurrent hypoglycemic episodes and/or dangerously low blood sugar levels can lead to progressive and irreversible brain damage and other health problems.  Fortunately, most patients with congenital HI survive into adulthood; however, even when on current standards of care, those who suffer with the disease may still experience hypoglycemia which can affect day-to-day functioning and lasting problems such as seizures, developmental delay and brain damage. While 14 different genetic defects have been found to cause congenital HI, more than one-third of the individuals who suffer with the disease have an unknown genetic cause.

The two most commonly used long-term medications, diazoxide and octreotide, are not Food and Drug Administration (FDA) approved for all forms of this condition and are often ineffective or cause intolerable side effects. In cases where congenital HI patients are unresponsive to medical management, surgical removal of a portion of the pancreas or the entire pancreas is required. In those with focal congenital HI (where only a small portion of the pancreas is affected), surgical removal of the specific affected area often results in a cure. In those with diffuse congenital HI (where the whole pancreas is affected), a near-total pancreatectomy is undertaken, but still about half of these children  continue to have hypoglycemia and require ongoing medical treatment for congenital HI.

It is important to note that surgery is performed in the US, but in many other places in the world, medical management is the only treatment option.

Post-Gastric Bypass Hypoglycemia

Hypoglycemia associated with bariatric surgery, especially Roux-en-Y gastric bypass surgery, can occur quickly and result in seizures, confusion, and focal neurological deficits. The hypoglycemia after gastric bypass surgery responds variably to nutritional changes and often requires treatment with medication.

Although hypoglycemia after bariatric surgery is associated with hyperinsulinemic responses to meals, the cause may be multifactorial. Postprandial hypoglycemia can develop months to years after surgery and occurs with a range of severity in post-gastric-bypass patients. Current treatment options include acarbose, somatostatin (octreotide), verapamil, and diazoxide, each having the risk of undesirable side effects. In more severe cases, a partial pancreatectomy or reversal of the gastric bypass may be required.

Insulinoma

Insulinomas, which are insulin over-producing tumors of the beta cells in the pancreas, are the most common cause of hypoglycemia related to HI. Insulinoma often manifests clinically as fasting hypoglycemia with discrete episodes of symptoms that indicate a shortage of glucose in the brain. If left untreated, potential problems include increased risk of neurological complications, recurrent seizures, brain damage or even death. Patients are generally categorized as having benign or malignant insulinomas, but insulinomas may be further characterized by disease severity. Surgical removal remains the preferred treatment choice, but medications to control hypoglycemia are often needed throughout the patient journey. Following surgery, patients may still require lifelong, episodic treatment to control hypoglycemic episodes.  Up to 10% of insulinomas prove to be malignant and surgical resection alone may not be curative.