Both hyperglycemia and hypoglycemia have been shown to modulate glucose transport into the brain; however, the impact of glycemic variability remains unknown. This study was undertaken to investigate the impact of glycemic variability on brain glucose transport kinetics amongst T1DM individuals.

Nine individuals with poorly-controlled T1DM (age 6F/3M, age 30±4 years, BMI 27±1.2 kg/m2, HbA1C 8.0±0.3%, duration of DM 17±5 years) underwent 1H magnetic resonance spectroscopy scanning in the occipital lobe to measure the change in intracerebral glucose levels during a 2-hour hyperglycemia clamp (target glucose 220 mg/dl). In addition for 5-6 days prior to scanning, individuals wore a continuous glucose monitor (Dexcom G4) to assess several measures of glycemic variability (EasyGV).

The mean change in brain glucose was 0.99±0.1 mmol/L. There was no significant relationship between HbA1C% and change in intracerebral glucose (P=0.31), which may be due to the narrow range of HbA1C. However, there were significant positive correlations between measures of glycemic variability and change in intracerebral glucose (Figure).

These findings suggest that the degree of glycemic variability can modulate brain glucose transport and highlight the need for future studies to investigate the impact of glycemic variability on brain glucose kinetics.


J. Hwang: None. L. Jiang: None. W. Lam: None. E. Sanchez Rangel: None. D.L. Rothman: None. G.F. Mason: Consultant; Self; UCB, Inc., Sumitomo Dainippon Pharma Co., Ltd. R. Sherwin: Other Relationship; Self; QuintilesIMS, MannKind Corporation. Research Support; Self; Regeneron Pharmaceuticals, Inc.. Other Relationship; Self; ICON plc..

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