? In intensively treated subjects with T1DM during hypoglycemia there is often a loss of both the counterregulatory response and the mild cognitive symptoms prior to severe cognitive dysfunction. Both of these adaptations are believed to contribute significantly to hypoglycemic unawareness, which increases the risk of severe hypoglycemia. Using a novel method combining 13C MRS and [2-13C] acetate infusion we found that cortical monocarboxylic acid transport (MCT) and metabolism is up regulated 2-fold in patients with intensively treated T1DM.
In Aim 1 we will assess whether increased usage of lactate, the monocarboxylic acid (MCA) with the highest concentration in blood during hypoglycemia, plays a significant role in preserving neuronal energy metabolism in subjects with intensively treated T1DM.
In Aim 2 we will assess whether MCT upregulation is specifically caused by recent exposure to extended hypoglycemia. The detailed understanding provided by these studies of cortical metabolic adaptations to hypoglycemia should aid in the development of strategies for counteracting them, which may help restore awareness of hypoglycemia in such patients.
In Aim 3 we will use a novel 1H MRS method for measuring brain glucose transport to assess upregulation of glucose transport in intensively treated TIDM.
In Aim 4 we will use an animal model to validate our interpretation that the increase in acetate transport and metabolism due to repeated hypoglycemia is due to upregulation of blood brain barrier MCT activity. Finally in Aim 5 we will further assess in the animal model whether the upregulation of MCT activity can potentially protect against hypoglycemic energy failure. If MCAs or alternatively medium chain fatty acids can protect against hypoglycemic energy failure they may potentially be administered as a protective therapy for nocturnal hypoglycemic episodes. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS051854-05
Application #
7487953
Study Section
Special Emphasis Panel (ZDK1-GRB-N (O1))
Program Officer
Mitler, Merrill
Project Start
2004-09-30
Project End
2010-07-31
Budget Start
2008-08-01
Budget End
2010-07-31
Support Year
5
Fiscal Year
2008
Total Cost
$526,218
Indirect Cost
Name
Yale University
Department
Psychiatry
Type
Schools of Medicine
DUNS #
043207562
City
New Haven
State
CT
Country
United States
Zip Code
06520
Chowdhury, Golam M I; Jiang, Lihong; Rothman, Douglas L et al. (2014) The contribution of ketone bodies to basal and activity-dependent neuronal oxidation in vivo. J Cereb Blood Flow Metab 34:1233-42
Herzog, Raimund I; Jiang, Lihong; Herman, Peter et al. (2013) Lactate preserves neuronal metabolism and function following antecedent recurrent hypoglycemia. J Clin Invest 123:1988-98
De Feyter, Henk M; Mason, Graeme F; Shulman, Gerald I et al. (2013) Increased brain lactate concentrations without increased lactate oxidation during hypoglycemia in type 1 diabetic individuals. Diabetes 62:3075-80
Hyder, Fahmeed; Sanganahalli, Basavaraju G; Herman, Peter et al. (2010) Neurovascular and Neurometabolic Couplings in Dynamic Calibrated fMRI: Transient Oxidative Neuroenergetics for Block-Design and Event-Related Paradigms. Front Neuroenergetics 2:
van Eijsden, Pieter; Hyder, Fahmeed; Rothman, Douglas L et al. (2009) Neurophysiology of functional imaging. Neuroimage 45:1047-54
Jiang, Lihong; Herzog, Raimund I; Mason, Graeme F et al. (2009) Recurrent antecedent hypoglycemia alters neuronal oxidative metabolism in vivo. Diabetes 58:1266-74
Shulman, Robert G; Hyder, Fahmeed; Rothman, Douglas L (2009) Baseline brain energy supports the state of consciousness. Proc Natl Acad Sci U S A 106:11096-101
Shulman, Robert G; Rothman, Douglas L; Hyder, Fahmeed (2007) A BOLD search for baseline. Neuroimage 36:277-81