New Key Publication: Impaired VLDL catabolism links hypoglycemia to hypertriglyceridemia in GSD Ia

Prevention of hypertriglyceridemia is one of the biomedical targets in Glycogen Storage Disease type 1a (GSD Ia) patients, yet it is unclear how hypoglycemia links to plasma triglyceride (TG) levels. We analyzed whole-body TG metabolism in normoglycemic (fed) and hypoglycemic (fasted) hepatocyte-specific glucose-6-phosphatase deficient (L-G6pc-/- ) mice. De novo fatty acid synthesis contributed substantially to hepatic TG accumulation in normoglycemic L-G6pc-/- mice. In hypoglycemic conditions enhanced adipose tissue lipolysis was the main driver of liver steatosis, supported by elevated free fatty acid concentrations in GSD Ia mice and -patients. Plasma VLDL levels were increased in GSD Ia patients and in normoglycemic L-G6pc-/- mice, and further elevated in hypoglycemic L-G6pc-/- mice. VLDL-TG secretion rates were doubled in normo- and hypoglycemic L-G6pc-/- mice, while VLDL-TG catabolism was selectively inhibited in hypoglycemic L-G6pc-/- mice. In conclusion, fasting-induced hypoglycemia in L-G6pc-/- mice promotes adipose tissue lipolysis and arrests VLDL catabolism. This mechanism likely contributes to aggravated liver steatosis and dyslipidemia in GSD Ia patients with poor glycemic control and may explain clinical heterogeneity in hypertriglyceridemia between GSD Ia patients.

by:

• Joanne A Hoogerland
• Fabian Peeks
• Brenda S Hijmans
• Justina C Wolters
• Sander Kooijman
• Trijnie Bos
• Aycha Bleeker
• Theo H van Dijk
• Henk Wolters
• Albert Gerding
• Karen van Eunen
• Rick Havinga
• Amanda C M Pronk
• Patrick C N Rensen
• Gilles Mithieux
• Fabienne Rajas
• Folkert Kuipers
• Dirk-Jan Reijngoud
• Terry G J Derks
• Maaike H Oosterveer

Read more: DOI: 10.1002/jimd.12380

Link to to the paper : https://pubmed.ncbi.nlm.nih.gov/33739445/