Endocrine Abstracts

Introduction: The incidence of adrenal insufficiency in cases of unexplained death in young children is unclear. It is also unclear whether there is a relationship between adrenal size and plasma cortisol concentration.

Methods: All post-mortem (PM) reports of sudden deaths in children in the West of Scotland between 2010 and 2012 were retrospectively analysed. Combined adrenal weight (g) was recorded and expressed as the percentage of total body weight (%TBW). Plasma cortisol was measured by immunoassay using a sample from the right atrium.

Results: Of 153 cases during the study period, 106 had data on adrenal weight and plasma cortisol. The median (5th, 95th) age was 5months (3 days, 11 years) with 70 cases (63%) under the age of 1 year. Median time to PM was 60 h (20, 144). There was no correlation between plasma cortisol and time to PM (r=−0.06, P=0.6). The median %TBW was 0.058 (0.025, 0.27) and the median plasma cortisol was 232 nmol/l (28, 1300). There was a positive correlation between total body weight and combined adrenal weight (r=0.4, P<0.0001). There was a weak positive correlation between %TBW and plasma cortisol levels (r=0.2, P=0.03), with a stronger correlation seen in children over 1-year-old (r=0.5, P=0.003). The lowest and highest plasma cortisol quartile had a median of 52 nmol/l (28, 95) and 946 nmol/l (477, 1973), respectively. In the lowest quartile, conditions associated with death included 17 cases (65%) of sudden unexpected death in infancy, three cases (12%) of drowning and two cases of seizure (8%). In the highest quartile cases included infection (six cases, 23%), sudden unexpected death in childhood (five cases, 19%) and hypoxic ischaemic encephalopathy (four cases, 15%) (P<0.0001).

Discussion: Although there is a relationship between circulating cortisol and relative adrenal size, there is substantial inter-individual variability. Cortisol levels are often low at PM but this is a less frequent finding in cases of infection.