Objective To investigate whether glycaemic profile is associated with multiorgan dysfunction and with response to hypothermia after perinatal hypoxic–ischaemic encephalopathy (HIE).

Design Post hoc analysis of the CoolCap Study.

Setting 25 perinatal centres in UK, USA and New Zealand during 1999–2002.

Patients 194/234 (83%) infants of ≥36 weeks' gestation with moderate-to-severe HIE enrolled in the CoolCap Study with documented plasma glucose levels and follow-up outcome.

Intervention Infants were randomised to head cooling for 72 hours starting within 6 hours of birth or standard care. Plasma glucose levels were measured at predetermined time intervals after randomisation.

Main outcome measure Unfavourable primary outcome was defined as death and/or severe neurodevelopmental disability at 18 months. Glycaemic profile (hypoglycaemia (≤40 mg/dL, ≤2.2 mmol/L), hyperglycaemia (>150 mg/dL, >8.3 mmol/L) and normoglycaemia) during 12 hours after randomisation was investigated for association with multiorgan dysfunction or risk reduction of primary outcome after hypothermia treatment.

Results Hypoglycaemia but not hyperglycaemia was associated with more deranged multiorgan function parameters (mean pH 7.23 (SD 0.16) vs 7.36 (0.13), p<0.001; aspartate transaminase 2101 (2450) vs 318 (516) IU/L, p=0.002; creatinine 1.95 (0.59) vs 1.26 (0.5) mg/dL, p<0.001) compared with normoglycaemia. After adjusting for Sarnat stage and 5 min Apgar score, only hyperglycaemic infants randomised to hypothermia had reduced risk of unfavourable outcome (adjusted risk ratio: 0.80, 95% CI 0.66 to 0.99), whereas hypoglycaemic and normoglycaemic infants did not.

Conclusions Early glycaemic profile in infants with moderate-to-severe HIE may help to identify risk of multiorgan dysfunction and response to therapeutic hypothermia.

Trial registration number NCT00383305.