Brain energy metabolism during hypoglycaemia in healthy and type 1 diabetic subjects.
Diabetologia
; 47(4): 648-51, 2004 Apr.
Article
in En
| MEDLINE
| ID: mdl-15298341
ABSTRACT
AIMS/HYPOTHESIS:
This study aimed to examine brain energy metabolism during moderate insulin-induced hypoglycaemia in Type 1 diabetic patients and healthy volunteers.METHODS:
Type 1 diabetic patients (mean diabetes duration 13 +/- 2.5 years; HbA1c 6.8 +/- 0.3%) and matched controls were studied before, during (0-120 min) and after (120-240 min) hypoglycaemic (approximately 3.0 mmol/l) hyperinsulinaemic (1.5 mU x kg(-1) min(-1)) clamp tests. Brain energy metabolism was assessed by in vivo 31P nuclear magnetic resonance spectroscopy of the occipital lobe (3 Tesla, 10-cm surface coil).RESULTS:
During hypoglycaemia, the diabetic patients showed blunted endocrine counter-regulation. Throughout the study, the phosphocreatinegamma-ATP ratios were lower in the diabetic patients (baseline controls 3.08 +/- 0.29 vs diabetic patients 2.65 +/- 0.43, p<0.01; hypoglycaemia 2.97 +/- 0.38 vs 2.60 +/- 0.35, p<0.05; recovery 3.01 +/- 0.28 vs 2.60 +/- 0.35, p<0.01). Intracellular pH increased in both groups, being higher in diabetic patients (7.096 +/- 0.010 vs. 7.107 +/- 0.015, p<0.04), whereas intracellular magnesium concentrations decreased in both groups (controls 377 +/- 33 vs 321 +/- 39; diabetic patients 388 +/- 47 vs 336 +/- 68 micromol/l; p<0.05). CONCLUSIONS/INTERPRETATION:
Despite a lower cerebral phosphocreatinegamma-ATP ratio in Type 1 diabetic patients at baseline, this ratio does not change in control or diabetic patients during modest hypoglycaemia. However, both groups exhibit subtle changes in intracellular pH and intracellular magnesium concentrations.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Brain Chemistry
/
Diabetes Mellitus, Type 1
/
Energy Metabolism
/
Hypoglycemia
Limits:
Adult
/
Humans
/
Male
Language:
En
Journal:
Diabetologia
Year:
2004
Document type:
Article
Affiliation country:
Austria