Glycemic control is essential for the management of diabetes. However, intensive glycemic control brings increased morbidity and mortality associated with hypoglycemia. This work tested the hypothesis that human brain networks have functional patterns of hierarchical recruitment in physiologic responses to induced hypoglycemia.

Design and Methods: Glycemic levels were clamped to 90, 65, 55 and 45 mg/dL in seven normal subjects and six persons with T1DM. Cerebral blood flow (CBF) was measured by arterial spin labelling with MRI.

Results: The thalamus, medial prefrontal (MPFC) and orbital prefrontal cortices (OPFC), and striatum have differential changes in CBF with progressive hypoglycemia. Significances were verified using threshold-free cluster enhancement methods.

Discussion: With progressively induced hypoglycemia, specific cortical and subcortical regions demonstrate characteristic alterations of CBF. These changes confirm existing data regarding the roles of the thalamus, MPFC, OPFC and striatum in responses to hypoglycemia. Furthermore, regional CBF reactivity to progressive, induced hypoglycemia has distinctive features for acute/recurrent hypoglycemia and hypoglycemia in T1DM. These characteristic features suggest mechanistic roles for human brain networks in physiologic responses to severe hypoglycemia and hypoglycemia-associated autonomic failure (HAAF).


J.J. Lee: None. A. Tanenbaum: None. A. Arbelaez: None.

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