Discussion on diagnosis and differential diagnosis of hypoglycemia

During the early neonatal life most of the infants have transient form of neonatal hypoglycemia either as a result of prematurity intrauterine growth restriction or being born to diabetic mother

Infant born to diabetic mother are macrosomic having characteristic large plethoric appearance

If however the Infant does not have a history of being born to a diabetic mother and is macrosomic having plethoric features with hypoglycemia , this should raise the possibility that the Infant has hyperinsulinemic hypoglycemia which may be due to autosomal recessive or autosomal dominant forms

If there is reducing sugar in urine such that clinitest test is positive but clinistix is negative and the patient has persistent jaundice with hepatosplenomegaly with normal development galactosemia may be considered

In a male infant if there is presence of microphallus with cholestatic jaundice in both genders or with evidence of midline facial defect such as cleft palate it should raise the possibility of hypopituitarism causing hypoglycemia due to deficiency of growth hormone or cortisol

The hypoglycemia episode due to  alcohol or salicyclic can be excluded by history

At the time of hypoglycemia The Following serum samples should be drawn

Beta hydroxybutyrate

Serum lactate

Free fatty acids

Insulin level, cortisol level ,ACTH, growth hormone level

These tests are then repeated after an intramuscular or intravenous injection of glucagon

In hyperinsulinemia, low Concentrations of serum c-peptide level confirm that hyperglycemia is due to exogenous insulin administration in which case the levels of insulin are high but c-peptide levels are low

However in case of deliberate or accidental ingestion of drugs that stimulate endogenous insulin secretion the levels of both insulin and c-peptide concentration will rise and it requires specialised laboratory methods to identify the offending substance

Pituitary- adrenal function and arginine-insulin stimulation test for growth hormone insulin like growth factor-1, insulin like growth factor binding protein 1 and may also be necessary.