β-hydroxybutyrate exposure restores mitochondrial function in skeletal muscle satellite cells of critically ill patients.
Level 5 - mechanism / opinion, no new human data
Ex vivo laboratory bench study using isolated human satellite cells
PubMed 38653008 · doi:10.1016/j.clnu.2024.04.009
What was done
Researchers isolated skeletal muscle satellite cells from vastus lateralis biopsies taken from 10 patients with ICU-acquired weakness and 10 controls (healthy volunteers or elective hip replacement patients). The isolated cells were cultured and exposed to β-hydroxybutyrate to evaluate its effects on cell proliferation via ELISA, bioenergetic parameters (ATP production, glycolytic and respiratory capacity) using extracellular flux analysis, electron transport chain complex function via high-resolution respirometry, and reactive oxygen species (ROS) production via confocal microscopy.
What was found
No specific numerical values, percentages, or effect sizes were reported in the abstract. Critical illness was reported to cause declines in maximal respiratory capacity, ATP production, glycolytic capacity, and complex II function, along with increased ROS production. Exposure to β-hydroxybutyrate restored complex II function to normal levels in ICU cells and significantly reduced ROS production in both control and ICU groups, but had no significant effect on global mitochondrial functions.
Why it matters
This study provides mechanistic evidence that ketone bodies such as β-hydroxybutyrate can target specific mitochondrial respiratory chain deficits and oxidative stress in muscle stem cells impaired by critical illness.
Limits
The study is an in vitro bench experiment using cultured cells, so results cannot be directly translated to in vivo human muscle physiology or clinical recovery. The sample size was small (10 per group), the control group combined healthy subjects with surgical patients, and the abstract omitted quantitative measurements, effect sizes, and concentration details.