Poor glycemic control is associated with central nervous system complications. We have previously shown that compared to healthy controls, individuals with uncontrolled T2DM have a blunted rise in brain glucose levels measured by 1H magnetic resonance spectroscopy (MRS). In this study, we investigate whether reduction in HbA1C improves intracerebral glucose levels. Six T2DM subjects with poor glycemic control were recruited (4F, age 46.0 ± 8.8 yrs, BMI 34.2 ± 4.1 kg/m2, HgbA1c 9.6 ± 1.1%) to participate in 1HMRS scanning at 4 Tesla during a hyperglycemic clamp (∼220 mg/dl) before and after a 12-week intervention to improve glycemic control through use of continuous glucose monitoring, intensification of diabetes regimen, and frequent visits with an endocrinologist and nutritionist. Following the intervention, HbA1c decreased by 2.1%±1.5 (P=0.02) with minimal BMI changes (P=0.10). Using a hierarchical linear regression model to compare glucose time courses during the clamp pre and post intervention, brain glucose levels were modestly and significantly higher during the clamp after the intervention (P=0.02) despite no differences in plasma glucose levels during the clamp (P=0.45). These findings suggest that brain glucose levels increase after improvement of glycemic control and provide evidence that reducing HbA1C may improve brain glucose transport and/or metabolism.


E. Sanchez Rangel: None. F. Gunawan: None. L. Jiang: None. M. Savoye: None. F. Dai: None. D.L. Rothman: None. G.F. Mason: None. J.J. Hwang: Research Support; Self; General Electric.


National Institutes of Health (DK109284)

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at http://www.diabetesjournals.org/content/license.