Glucose and leucine kinetics in idiopathic ketotic hypoglycaemia.
OBJECTIVE
To investigate glucose and leucine kinetics in association with metabolic and endocrine investigations in children with ketotic hypoglycaemia (KH) in order to elucidate the underlying pathophysiology.


METHODS
Prospective interventional study using stable isotope tracer in nine children (mean age 4.23 years, range 0.9-9.8 years; seven males) with KH and 11 controls (mean age 4.57 years, range 0.16-12.3 years; four males).


RESULTS
Plasma insulin levels were significantly lower in KH compared to subjects in the non-KH group. Plasma ketone body levels were significantly higher in KH than in non-KH. Basal metabolic rate was significantly higher in subjects with KH (45.48+/-7.41 v 31.81+/-6.72 kcal/kg/day) but the respiratory quotients were similar in both groups (KH v non-KH, 0.84+/-0.05 v 0.8+/-0.04. Leucine oxidation rates were significantly lower in children with KH (12.25+/-6.25 v 31.96+/-8.59 micromol/kg/h). Hepatic glucose production rates were also significantly lower in KH (3.84+/-0.46 v 6.6+/-0.59 mg/kg/min).


CONCLUSIONS
KH is caused by a failure to sustain hepatic glucose production rather than by increased glucose oxidation rates. Energy demand is significantly increased, whereas leucine oxidation is reduced.
Bodamer
O A
OA
Biochemical Genetics and National Neonatal Screening Laboratories, University Children's Hospital Vienna, Vienna, Austria. olaf.bodamer@meduniwien.ac.at
Hussein
K
K
Morris
A A
AA
Langhans
C-D
CD
Rating
D
D
Mayatepek
E
E
Leonard
J V
JV
D000409:Alanine / Q000097:blood; D000597:Amino Acids, Branched-Chain / Q000097:blood; D001481:Basal Metabolism; D002153:Calorimetry, Indirect; D002331:Carnitine / Q000031:analogs & derivatives / Q000097:blood; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005215:Fasting; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007003:Hypoglycemia / Q000378:metabolism*; D007223:Infant; D007328:Insulin / Q000097:blood; D007662:Ketosis / Q000378:metabolism*; D007930:Leucine / Q000378:metabolism*; D008297:Male
D000597:Amino Acids, Branched-Chain; D007328:Insulin; C116917:acylcarnitine; D007930:Leucine; D005947:Glucose; D000409:Alanine; D002331:Carnitine