Somatostatin treatment of insulin excess due to beta-cell adenoma in a neonate

Neonatal hyperinsulinemic hypoglycemia: heterogeneity of the syndrome and keys for differential diagnosis

The two major forms of infantile persistent hyperinsulinemic hypoglycemia require different treatments, but are difficult to differentiate during surgery. Indeed, one is characterized by focal adenomatous hyperplasia often macroscopically invisible, whereas the other consists of a diffuse, but discreet, beta-cell abnormality. We evaluated, in a large series of persistent hyperinsulinemic hypoglycemia, the reliability of two criteria in differentiating these two forms: the mean beta-cell nuclear radius (MNR) and the beta-cell nuclear crowding, i.e. the number of nuclei per 1000 micron 2 beta-cell (BCNC). The values of the largest MNR and of BCNC in cases bearing a focal lesion (respectively, 3.27 microns +/- 0.25 and 14.62 +/- 1.78) were significantly different from those in the diffuse pathology (4.25 microns +/- 0.43 and 10.00 +/- 1.55). Setting the threshold value of MNR at 3.70 microns and that of BCNC at 12.00 enabled correct classification of 90.9% of the diffuse and 100% of the focal forms. beta-Cell nuclear analysis can thus contribute to a subclassification of the syndrome, not allowed by clinical or biological data. If performed during surgery it could help in determining the extent of pancreatectomy necessary to cure the patient, as the diffuse form, with abnormal nuclei in the whole pancreas, requires subtotal to near-total pancreatectomy, whereas the focal form, devoid of abnormal insular beta-cell nuclei, can be cured by partial pancreatectomy.

Clinical use of the long acting somatostatin analogue octreotide in pediatrics

Preliminary data of the use of the long-acting somatostatin analog octreotide (Sandostatin) in pediatrics are reported. In nesidioblastosis and other hyperinsulinemic conditions, timely treatment with octreotide can protect cerebral function and may reduce mortality. The acute use of octreotide produces prompt elevation of blood glucose, even in patients who fail to respond to diazoxide. In addition, it may be possible to avoid the need for partial or subtotal pancreatectomy by the long-term use of octreotide. As in adults, octreotide should find a place in the symptomatic treatment of secretory diarrhea, notably the watery diarrhea hypokalemia-achlorhydria complex and pancreatic cholera syndrome. Octreotide has been shown to be effective in the treatment of familial tall stature by reducing height velocity and final height. Responses to octreotide therapy vary and the individual responsiveness must be extensively studied.

Short- and long-term use of octreotide in the treatment of congenital hyperinsulinism

Octreotide, a long-acting analog of somatostatin that inhibits insulin release, has the potential to control hypoglycemia in infants with congenital hyperinsulinism. To examine the efficacy and side effects of octreotide, we evaluated therapy between 1988 and 1993 in 16 infants who did not respond to diazoxide. In nine patients with onset of severe hypoglycemia in the first days of life, octreotide was helpful in stabilizing plasma glucose levels and allowed reductions in the rates of glucose infusion; however, glucose control was inadequate to avoid subtotal pancreatectomy. In two of these nine patients postoperatively and in seven other infants, a trial of long-term treatment with octreotide was undertaken. Four were treated successfully for up to 4.3 years. Octreotide therapy was not associated with thyroid deficiency and caused only transient malabsorption. All patients receiving long-term therapy had some decrease in linear growth and two had subnormal plasma concentrations of insulin-like growth factor I and insulin-like growth factor binding protein 3 compatible with suppression of growth hormone by octreotide. Resistance to octreotide therapy, even with increasing doses, occurred in all patients. These results suggest that octreotide may aid in the acute or long-term treatment of congenital hyperinsulinism in a limited number of selected cases.

Tolerance to somatostatin analogue in a preterm infant with islet cell dysregulation syndrome

An infant of 31 weeks' gestation presented with refractory neonatal hypoglycaemia secondary to islet cell dysregulation. Treatment was started with somatostatin analogue and his glycaemic control improved initially. Tolerance developed, however, in that the dose required to maintain control increased by a factor of 40. The infant subsequently underwent pancreatectomy. It is safe to use somatostatin analogue in a preterm infant, but tolerance to the drug rapidly develops.

Hyperinsulinism in infancy

Five infants with persistent hypoglycaemia due to hyperinsulinism were reported. Provocative tests for insulin release were unhelpful. Diazoxide was useful in the treatment of three patients but many side-effects were observed. These included petechial rash, hypertrichosis, acute renal failure, fluid retention and cardiac failure. Two patients underwent spontaneous remission. Three patients had nesidioblastosis, two of whom were subjected to 95% pancreatectomy. Postoperatively, recurrence of hypoglycaemia was due to hyperinsulinism in one patient and to presumed glucagon deficiency in the other. Phenytoin effectively corrected the hypoglycaemia in the patient who had postoperative hyperinsulinism. It is recommended that medical therapy with diazoxide (10-15 mg/kg per day) together with a diuretic be commenced once hyperinsulinism is diagnosed. Subtotal pancreatectomy should be performed early in these patients if hypoglycaemia cannot be controlled with medical therapy or if side-effects of treatment are documented.

Pancreatic venous samplings in infants and children with primary hyperinsulinism

The authors present 19 cases of hyperinsulinism in children worked up with selective pancreatic venous samplings (PVS). Focal lesions were found in 7, diffuse secretion in 8 and normal insulin levels in 4. In three patients with focal hypersecretion less extensive surgery could be performed and confirmed the presence of focal lesions in two. These preliminary results are encouraging and PVS seems to be a valuable technic for detection of focal lesions in the pancreas of children with hyperinsulinism.

Somatostatin analogue SMS 201-995 in the short-term management of neonatal hyperinsulinism due to nesidioblastosis

A neonate with persistent hyperinsulinaemic hypoglycaemia is presented in whom the use of intravenous somatostatin SMS 201-995 allowed good glycaemic control over 10 days. A 95% pancreatectomy was then performed.

Long-term use of somatostatin analogue SMS 201-995 in the treatment of hypoglycaemia due to nesidioblastosis

An infant presented with hypoglycaemia secondary to nesidioblastosis. Subtotal pancreatectomy failed to prevent recurrent post-operative hypoglycaemia. Subcutaneous somatostatin analogue (SMS 201-995) was shown to increase the blood concentrations of glucose and B-hydroxybutyrate while lowering serum insulin levels. Regular use of somatostatin analogue was helpful in long term management without causing significant side effects.

Persistent neonatal hyperinsulinism

Over a 3-year period, the diagnosis of persistent neonatal hyperinsulinism (PNH) was made in seven infants, from an unselected cohort of 18,726 births, all of Saudi Arabian origin. Thus the incidence of PNH was one in 2,675 births. The high incidence, associated consanguinity, and occurrence in siblings suggest that PNH may be inherited as an autosomal recessive disorder.

Somatostatin and octreotide: literature review and description of therapeutic activity in pancreatic neoplasia

The somatostatins represent endogenous substances that serve a diversity of functions in the body. These activities are just beginning to be understood and could have major implications in the treatment of human disease. Their chief pharmacologic activities lie in the modification or modulation of protein hormone synthesis of the gastrointestinal system; a great many other systems may be involved as well. Since the discovery of the therapeutic potentials of naturally isolated somatostatins, attempts have been made to design newer analogs more conducive to practical use. Such an example is long-acting somatostatin analog octreotide. Literature has recently begun to appear describing the therapeutic activities of this and other similar compounds and the first steps to understanding their clinical pharmacology are being taken. Surprising activity has been found in the palliative treatment of a wide variety of formerly resistant gastrointestinal syndromes and endocrine tumors. These activities may have considerable future impact on the treatment of disease involving hormonal imbalance or inappropriate secretion.

Studies on insulin secretion by monolayer cultures of normal and tumorous human pancreatic cells. Effects of glucose, somatostatin and SMS 201-995

Recently, somatostatin analogs have been introduced which can be used clinically in the treatment of tumorous or functional hypoglycemia. In the present study we investigated in vitro the regulation, the degree of autonomy and the sensitivity to natural somatostatin and its analog SMS 201-995 of insulin secretion by monolayer cultures of human pancreatic cells obtained from patients with insulinomas and from a newborn with nesidioblastosis. All cultures released insulin upon the addition of dibutyryl-cAMP and calcium, demonstrating their intact viability. Insulin secretion from nontumorous pancreatic cells surrounding an insulinoma was dose-dependently stimulated by glucose. In contrast, insulin release by B cells from a patient with nesidioblastosis and from 2 insulinomas was not stimulated by the addition of glucose. Native somatostatin (SRIF) and the synthetic analog SMS 201-995 inhibited insulin secretion from all cultures. The inhibitory effects of SRIF and SMS in the culture from the nesidioblastosis tissue, could be reversed by the addition of 11.2 mmol glucose/l, but not in one of the insulinoma cultures. This demonstrates that some sensitivity to glucose is present in B cells from the nesidioblastosis tissue, despite the unresponsiveness to glucose alone. Insulin release by insulinoma cells was blocked by somatostatin, while it was inhibited to some extent only in the cultures of nontumor B cells and of cells from the nesidioblastosis tissue. In conclusion, it was shown that insulin release by the cultured B cells obtained from several pathological conditions differed with regard to the autonomy of hormone release (glucose sensitivity) and the sensitivity to somatostatin and its analog.

An immunohistochemical study of islet cells with macronuclei in infancy

The presence of hypertrophic islet cells in infancy as evidenced by nuclear enlargement (2 to 6 times normal size) has been mentioned as a morphological accompaniment of hyperinsulinemic hypoglycemia of infancy. We report an immunohistochemical and semiquantitative study of hypertrophic islet cells in 14 infants with neonatal hypoglycemia (10 with documented persistent neonatal hypoglycemia and 4 with probable persistent neonatal hypoglycemia) and 6 infants born to diabetic mothers (IDM), using an indirect immunoperoxidase methods for the demonstration of insulin, somatostatin, and glucagon. Quantitation of immunoreactivity was performed in each case on 20 hypertrophic cells. Polyploid cells were positive for insulin and somatostatin but negative for glucagon; insulin-positive cells outnumbered somatostatin-positive cells in both groups. As nuclear hypertrophy is considered to be a sign of hyperfunction, our findings are in accordance with the concept that IDM involves reactive beta-cell hypertrophy and similar findings in the pancreases of infants with persistent neonatal hypoglycemia (PNH) suggest a primary dysfunction of their beta cells, too.

Pathophysiology, diagnosis, and management of glucose homeostasis in the neonate

The neonate appears to be in a transitional stage of glucose homeostasis. Maturation of neonatal glucose homeostasis requires coordination of opposing hormonal, neural, and enzymatic controls. The vulnerability of the neonate to carbohydrate disequilibrium has been described by tracing the maturation of carbohydrate homeostasis physiologically. The many examples of neonatal hypoglycemia and hyperglycemia have been enumerated. Much information in recent years has increased our understanding of the mechanism of these conditions in the newborn. Continued research of the biochemical and physiologic bases for alterations of carbohydrate metabolism should further enhance our ability to diagnose and treat the neonate effectively.

Experience with 95% pancreatectomy and splenic salvage for neonatal nesidioblastosis

Conventional 85% pancreatectomy with splenectomy performed for management of hypoglycemia of neonatal nesidioblastosis has been followed by a dismal prognosis characterized by post-splenectomy sepsis, recurrent hypoglycemia, permanent brain damage, and a high mortality. For our last eight infants we have found it possible to remove at least 95% of the pancreas, preserving the blood supply to the spleen as well as the duodenum. This has permitted satisfactory control of the hypoglycemia and long-term septic complications have been avoided. Follow-up evaluation up to 20 years with successful control of hypoglycemia without progressive brain damage indicates the value of this primary extensive surgical approach.

Surgical treatment of organic pancreatic hypoglycemia in the pediatric age

From 1974 to 1980, 6 patients were operated upon for organic hyperinsulinism. 218 patients reported in the last 5 years are studied. Age at onset of symptoms is the most important factor. In infants the diagnosis is urgent. A severe mental retardation can result from waste of time in diagnosis and treatment. Simultaneous measurement of blood glucose and insulinemia during fasting and feeding periods is sufficient. Diffuse lesions are frequent, even associated with Islet cell adenoma. Surgery based upon local portal insulinemia must be adequately large and should avoid repeated pancreatectomy. In older children the diagnosis is easy. When a localised lesion is the pathologic feature, after a complete exposure of the gland, local excision is the technique of choice.

Plasma somatostatin concentration in the preterm neonate

Plasma somatostatin concentration was measured by radioimmunoassay in 26 preterm neonates (mean gestational age 34 weeks). None were seriously ill and they were all fed with breast-milk 12 h after birth. In a longitudinal study the concentrations were (mean +/- SEM): 21 +/- 2 pmol/l (n = 8) at 2-8 h of age, 24 +/- 2 pmol/l (n = 11) at the age of 2 days and 25 +/- 2 pmol/l (n = 15) at the age of 8 days. These levels were significantly higher than in 30 healthy control adults: 11 +/- 1 pmol/l (P less than 0.01). Gavage with breast milk on the 2nd day induced a significant decrease from 21 +/- 4 to 15-2 pmol/l in 60 min (P less than 0.05). This data shows that the high plasma levels in neonates correspond to the high density of somatostatin in the neonatal pancreas and digestive tract. It also indicates that somatostatin is regulated by feeding in the neonate.

Effect of somatostatin and two of its analogues on basal and arginine-stimulated insulin and glucagon secretion in the dog

Two analogues of somatostatin (D-Trp8,D-Cys14-somatostatin, and the octapeptide DesAA1,2,3,4,13,14,D-Trp8,GABA12-somatostatin) were compared with somatostatin using infusions of 0.1 and 0.5 microgram . kg-1 . min-1 in conscious dogs. Basal concentrations of insulin and glucagon were markedly and similarly lowered by all three somatostatin (SRIF) compounds at either dose. Arginine stimulation of insulin and glucagon secretion was entirely abolished by SRIF and by the octapeptide during infusion at 0.1 microgram . kg-1 . min-1 but both hormones were only partly inhibited by D-Trp8,D-Cys14-SRIF. The higher dose (0.5 microgram . kg-1 . min-1) of all three SRIF peptides lowered plasma insulin and glucagon before and during arginine stimulation. The recovery of plasma insulin and glucagon was delayed after discontinuation of the D-Trp8,D-Cys14-SRIF, and particularly after the octapeptide when compared with SRIF suggesting a longer duration of action of the analogues. The results did not confirm the previously suggested selective suppression of glucagon by D-Trp8,D-Cys14-SRIF. The new octapeptide appears to be promising for future clinical studies due to its potent inhibitory effect on insulin and glucagon, and its prolonged duration of action.

Effect of somatostatin infusion on intermediary metabolism and entero-insular hormone release in infants with hyperinsulinaemic hypoglycaemia

The hypoglycaemia of infantile hyperinsulinism is often exceedingly difficult to control. The use of somatostatin has been advocated recently in such infants because of its effect on inhibiting insulin release, but nothing is known of the wider effects of this potent hormone in the young child. Two infants presenting at 9 weeks and 5 days of age with severe hyperinsulinaemic hypoglycaemia were studied during an infusion of somatostatin. In both infants normoglycaemia was restored with suppression of insulin secretion. An increase in blood ketone bodies occurred, but no change was seen in blood pyruvate, lactate or alanine concentrations. The plasma concentrations of glucagon, cortisol, growth hormone, motilin, pancreatic polypeptide, gastric inhibitory of polypeptide, neurotensin, gastrin and vasoactive intestinal peptide decreased markedly during the somatostatin infusion. No consistent change occurred in plasma enteroglucagon or secretin values. We conclude that somatostatin effectively suppresses abnormal insulin secretion in infants, but it has profound effects on the release of nine other hormones. Further studies are needed to define the consequences of suppressing the release of these hormones before somatostatin can be used routinely in the management of infantile hyperinsulinism.

Intractable diarrhoea in a patient with vasoactive intestinal peptide-secreting neuroblastoma. Attempted control by somatostatin

A 1 1/2 year old child developed profuse watery diarrhoea, shown to be due to excessive plasma vasoactive intestinal peptide (VIP) levels, whilst on treatment for metastatic neuroblastoma. Because it was unresponsive to alternative treatment, an attempt was made to control the diarrhoea with a somatostatin infusion. The attempt failed despite the fact that serum VIP levels were substantially reduced. Possible reasons for failure are discussed and the importance of plasma VIP as a marker for maturation in neuroblastoma emphasised.