At 11 1/2 months of age, my son was diagnosed with “severe” hypoglycemia and hyperinsulinism. He is currently on diazoxide three times daily and finger stick tested twice daily. He had two seizures that led us to this current diagnosis. Will he outgrow this condition? How common is type 2 diabetes with this condition? He is currently 18 months old and I am very concerned. I have gotten two opinions from different specialists. What could have caused this? Can it be hereditary? We have diabetics on both sides of the family and I, his mother, have reactive hypoglycemia.

Diazoxide is the conventional treatment for Persistent Hyperinsulinemic Hypoglycemia of Infancy (PHHI, and, because of late onset in your son’s case, it is likely that the hypoglycemia can be relatively easily controlled. This is such a rare condition that accurate statistics really aren’t yet available, but, in some reports, recovery has been shown at somewhat less than 50%.

PHHI represents a variety of genetically determined disorders that result in an increase in the pancreas of insulin producing cells, and there a number of subvariants. The two main groups are: first, the one where the islet hyperplasia is aggregated into a discrete adenoma, and this is linked to a mutation in the short arm of chromosome 11; secondly, the diffuse type where the abnormality is in what is called the Sulphonylurea Receptor site (SUR, and it is inherited as an autosomal recessive. The condition is not related to any form of diabetes, however some cases may end up requiring insulin as a consequence of surgery.

Recently, there have been some suggestions that the drug nifedipine, a calcium channel blocker drug that used to be used for high blood pressure, may have fewer side effects than diazoxide especially if combined with raw cornstarch in the diet as an additional guard against hypoglycemia. You might give the reference by Bis, F. in Jour.Pediat.Endocrinol & Metab. vol 12, p873 to your sons’s doctor if he/she is interested. If there are difficulties with medical management, the question of surgery will come up, and, if this does, it would be important, first of all, to use modern imaging techniques to make sure whether the problem was one of diffuse nesidioblastosis or an adenoma. The whole removal of an adenoma or 85% to 95% of the pancreas has been successful in combating hypoglycemia, but there is always the risk of either having to repeat the operation because of insufficient removal or of taking away too much and needing insulin supplementation, and, perhaps also, supplementation of digestive enzymes.

DOB