Hypoglycaemia and Russell-Silver syndrome

Abstract

Aim: To determine both the incidence and aetiology of chronic hypoglycaemia in symptomatic children with Russell-Silver syndrome (RSS) during the first four years of life.

Study design: Twenty-four children with RSS under the age of 4 years, who had either clinical symptoms of hypoglycaemia or previous evidence of biochemically documented hypoglycaemia, were admitted to hospital for 48 hours to perform a 24-h cortisol/glucose profile and a diagnostic fast in those who did not develop spontaneous hypoglycaemia. A dietary assessment was also performed. Glucose profile was assessed in 20 children and cortisol profile in 16; combined glucose and cortisol profile in 15 children. Eight children had a diagnostic fast. Mean chronological age at time of assessment was 2.2 +/- 0.8 years (range 1.1-3.9 years).

Results: Ten of 24 children had previously been documented as having hypoglycaemia. Seven of 12 patients were growth hormone (GH) insufficient after a glucagon test. Their feeding pattern was described as 'poor and picky eaters' in all, seven requiring nasogastric tube feeding. The mean spontaneous energy intake (n = 8) was 56 +/- 19.6 kcal/kg/day (range 38-90). Nocturnal sweating was the commonest symptom (23.96%), followed by irritability (11.46%), tantrums (7.29%), pallor and shakiness (3.13%). The glucose profile in seven children showed hypoglycaemia but only four were symptomatic. None of the children was cortisol deficient. The mean period of fasting was 11.8 +/- 4 hours (range 3-18 h). No metabolic/hormonal abnormality, with the exception of GH insufficiency, was detected at the time of hypoglycaemia.

Conclusion: Children with RSS are prone to develop spontaneous hypoglycaemia especially if they are not fed both frequently and regularly. The most likely explanation is accelerated starvation and/or GH insufficiency. We suggest guidelines to minimise hypoglycaemia in these children.