[HTML][HTML] Fructose levels are markedly elevated in cerebrospinal fluid compared to plasma in pregnant women
JJ Hwang, A Johnson, G Cline, R Belfort-DeAguiar… - PLoS …, 2015 - journals.plos.org
PLoS One, 2015•journals.plos.org
Background Fructose, unlike glucose, promotes feeding behavior in rodents and its
ingestion exerts differential effects in the human brain. However, plasma fructose is typically
1/1000th of glucose levels and it is unclear to what extent fructose crosses the blood-brain
barrier. We investigated whether local endogenous central nervous system (CNS) fructose
production from glucose via the polyol pathway (glucose→ sorbitol→ fructose) contributes to
brain exposure to fructose. Methods In this observational study, fasting glucose, sorbitol and …
ingestion exerts differential effects in the human brain. However, plasma fructose is typically
1/1000th of glucose levels and it is unclear to what extent fructose crosses the blood-brain
barrier. We investigated whether local endogenous central nervous system (CNS) fructose
production from glucose via the polyol pathway (glucose→ sorbitol→ fructose) contributes to
brain exposure to fructose. Methods In this observational study, fasting glucose, sorbitol and …
Background
Fructose, unlike glucose, promotes feeding behavior in rodents and its ingestion exerts differential effects in the human brain. However, plasma fructose is typically 1/1000th of glucose levels and it is unclear to what extent fructose crosses the blood-brain barrier. We investigated whether local endogenous central nervous system (CNS) fructose production from glucose via the polyol pathway (glucose→sorbitol→fructose) contributes to brain exposure to fructose.
Methods
In this observational study, fasting glucose, sorbitol and fructose concentrations were measured using gas-chromatography-liquid mass spectroscopy in cerebrospinal fluid (CSF), maternal plasma, and venous cord blood collected from 25 pregnant women (6 lean, 10 overweight/obese, and 9 T2DM/gestational DM) undergoing spinal anesthesia and elective cesarean section.
Results
As expected, CSF glucose was ~60% of plasma glucose levels. In contrast, fructose was nearly 20-fold higher in CSF than in plasma (p < 0.001), and CSF sorbitol was ~9-times higher than plasma levels (p < 0.001). Moreover, CSF fructose correlated positively with CSF glucose (ρ 0.45, p = 0.02) and sorbitol levels (ρ 0.75, p < 0.001). Cord blood sorbitol was also ~7-fold higher than maternal plasma sorbitol levels (p = 0.001). There were no differences in plasma, CSF, and cord blood glucose, fructose, or sorbitol levels between groups.
Conclusions
These data raise the possibility that fructose may be produced endogenously in the human brain and that the effects of fructose in the human brain and placenta may extend beyond its dietary consumption.
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