ABSTRACT
AIM: To assess the value and safety of fasts for investigating hypoglycaemia or suspected metabolic disease. STUDY DESIGN: Review of all diagnostic fasts performed over a 2.5 year period. SETTING: The neonatal intensive care unit and programmed investigation unit at a tertiary referral centre for endocrinology and metabolic disease. RESULTS: 138 diagnostic fasts were performed during the study period. Hypoglycaemia (< 2.6 mmol/l) occurred in 54 cases but in only four did the blood glucose concentration fall below 1.5 mmol/l. One patient became unwell as a result of a fast, but prompt treatment averted any sequelae. Specific endocrine or metabolic defects were identified in 30 cases, the most common being hyperinsulinism and beta-oxidation defects. CONCLUSIONS: Fasting is safe if conducted on an experienced unit with appropriate guidelines. It continues to provide useful information for diagnosis and management, particularly in cases of hyperinsulinism. Diagnoses should, however, be established by lower risk procedures whenever possible. Thus specimens for metabolic and endocrine studies should be obtained during the presenting episode and blood acylcarnitine species should be analysed prior to fasting.
Subject(s)
Fasting/metabolism , Hypoglycemia/etiology , Metabolic Diseases/diagnosis , 3-Hydroxybutyric Acid , Age Distribution , Child , Child, Preschool , Evaluation Studies as Topic , Fasting/adverse effects , Fatty Acids/metabolism , Fatty Acids, Nonesterified/blood , Humans , Hydroxybutyrates/blood , Hyperinsulinism/diagnosis , Infant , Infant, Newborn , Oxidation-ReductionABSTRACT
One of the most important criteria for good health in childhood is normal growth. Taking regular accurate measurements of length and plotting them on a centile chart is essential to spot early signs of growth disorders. Be alert for a "zig-zag" pattern on the chart: it could indicate psychosocial dwarfism (see opposite). Length is more important than weight for identifying growth disorders. Lack of love, or an adverse emotional or social environment, can cause growth failure even in a child who is eating enough. Such children have a condition called psychosocial dwarfism, which is due to hypopituitarism (too little growth hormone secretion from the pituitary gland). This condition does not respond to growth hormone treatment. Once the child is placed in an alternative environment, eg a good foster home, the hypopituitarism is reversed and rapid "catch-up" growth takes place. It often emerges that such children have been physically, emotionally or sexually abused.
