Poor sleep quality has been associated with increased risk of metabolic syndrome and type 2 diabetes as well as acceleration of neurodegenerative diseases. In rodents, sleep restriction decreases glucose transport into the brain via downregulation of GLUT1, the primary glucose transporter at the blood-brain barrier. However, little is known about the association between sleep quality and glucose transport and metabolism in the human brain. In this exploratory analysis, we quantified cerebral glucose levels amongst individuals with good and poor sleep quality as defined by the widely used and well-validated Pittsburgh Sleep Quality Index (PSQI), which assesses 7 different components of sleep quality over a 1 month time period (PSQI≥5 = Poor sleep; PSQI<5 = Good sleep). Twelve healthy subjects completed the PSQI questionnaire. Eight (6F, age 27.6 ± 5.7, BMI 26.6 ± 8.2 kg/m2, HgbA1c 5.4 ± 0.2%) had good and 4 (2F, age 29.5± 2.4, BMI 27.8 ± 6.5 kg/m2, HgbA1c 5.2 ± 0.2%) had poor sleep. All subjects underwent 13C magnetic resonance spectroscopy brain scanning at 4 Tesla during a 2-hour hyperglycemic clamp (plasma glucose target ∼180 mg/dl) to measure absolute cerebral glucose levels as part of a larger study to investigate obesity and cerebral glucose metabolism. There were no differences in age, BMI, or HbA1c levels between groups with good and poor sleep. Individuals with good sleep had 63% higher absolute cerebral glucose levels at steady state compared to those with poor sleep (3.4 ± 0.7 mmol/L vs. 2.1 ± 0.9 mmol/L, p=.017). Higher PSQI scores correlated with lower absolute cerebral glucose levels (r= -0.725, p=0.008, PSQI for all subjects (mean±SD) = 4 ± 2). In this pilot and exploratory study, individuals with poor sleep quality have significantly lower absolute cerebral glucose levels, which suggests an association between poor sleep and altered cerebral glucose transport and/or metabolism. These findings may have wide-ranging implications for understanding the effects of sleep on brain function.
T.K. Stanley: None. F. Gunawan: None. N.S. Redeker: None. L. Jiang: None. A. Coppoli: None. D.L. Rothman: None. G.F. Mason: None. J. Hwang: Research Support; Self; General Electric.
American Diabetes Association (1-17-ICTS-013 to J.H.); National Institutes of Health (1R03DK121048)