Brain glucose concentrations in patients with type 1 diabetes and hypoglycemia unawareness

AB Criego, I Tkac, A Kumar, W Thomas… - Journal of …, 2005 - Wiley Online Library
AB Criego, I Tkac, A Kumar, W Thomas, R Gruetter, ER Seaquist
Journal of neuroscience research, 2005Wiley Online Library
Although it is well established that recurrent hypoglycemia leads to hypoglycemia
unawareness, the mechanisms responsible for this are unknown. One hypothesis is that
recurrent hypoglycemia alters brain glucose transport or metabolism. We measured steady‐
state brain glucose concentrations during a glucose clamp to determine whether subjects
with type 1 diabetes and hypoglycemia unawareness may have altered cerebral glucose
transport or metabolism after exposure to recurrent hypoglycemia. We compared 14 subjects …
Abstract
Although it is well established that recurrent hypoglycemia leads to hypoglycemia unawareness, the mechanisms responsible for this are unknown. One hypothesis is that recurrent hypoglycemia alters brain glucose transport or metabolism. We measured steady‐state brain glucose concentrations during a glucose clamp to determine whether subjects with type 1 diabetes and hypoglycemia unawareness may have altered cerebral glucose transport or metabolism after exposure to recurrent hypoglycemia. We compared 14 subjects with diabetes and hypoglycemia unawareness to 27 healthy control subjects. Brain glucose concentrations were measured under similar metabolic conditions using in vivo 1H nuclear magnetic resonance (NMR) spectroscopy at 4 Tesla during a hyperglycemic clamp (plasma glucose = 16.7 mmol/l) with somatostatin and insulin. Subjects with type 1 diabetes and hypoglycemia unawareness had significantly higher brain glucose concentrations compared to that in controls under the same conditions (5.5 ± 0.3 vs. 4.7 ± 0.1 μmol/g wet weight, P = 0.016). These data suggest that changes in brain glucose transport or metabolism may occur as a result of recurrent hypoglycemia. © 2004 Wiley‐Liss, Inc.
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