Premium
Alanine infusion during hypoglycaemia partly supports cognitive performance in healthy human subjects
Author(s) -
Evans M. L.,
Hopkins D.,
Macdonald I. A.,
Amiel S. A.
Publication year - 2004
Publication title -
diabetic medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.474
H-Index - 145
eISSN - 1464-5491
pISSN - 0742-3071
DOI - 10.1111/j.1464-5491.2004.01174.x
Subject(s) - medicine , endocrinology , alanine , saline , glucagon , hypoglycemia , effects of sleep deprivation on cognitive performance , alanine transaminase , hormone , diabetes mellitus , cognition , biochemistry , chemistry , amino acid , psychiatry
Aim To investigate the potential for the non‐glucose metabolic substrate alanine to support brain function during glucose deprivation in man. Methods Seven healthy men were studied on two occasions using a hyperinsulinaemic glucose clamp to lower arterialized plasma glucose to 2.5 mmol/l, in the presence of either 2 mmol/kg/h alanine infusion or saline, measuring counter‐regulatory hormonal responses, symptoms generated and cognitive function with a mini‐battery of tests sensitive to hypoglycaemia. Results Alanine infusion elevated plasma alanine (peak value 1481 ± 1260 vs. 138 ± 32 µmol/l, P = 0.02 alanine vs. saline) and lactate (peak value 3.09 ± 0.14 vs. 2.05 ± 0.12 mmol/l, P = 0.02). Cognitive function assessed by the Stroop word and colour subtests deteriorated less with alanine than saline ( P < 0.01 for both). Other cognitive function tests deteriorated equally and counter‐regulatory hormones rose equally during hypoglycaemia in both studies ( P > 0.34) except for increased glucagon with alanine (peak 260 ± 53 vs. 91 + 8 ng/l, P = 0.03). There was no significant effect of alanine on either autonomic or neuroglycopenic symptom scores. Conclusions Some, but not all, aspects of cognitive performance may be supported by an alanine infusion during hypoglycaemia. It is not clear whether alanine supports brain function directly or via increased availability of lactate. These data contribute to the growing evidence that regional metabolic differences exist in the brain's ability to use non‐glucose fuels during hypoglycaemia. Diabet. Med. (2004)