Lecture Notes: The Metabolic Link Podcast - Keto Adapted Phenotype on Muscle

Introduction

• Podcast Name: The Metabolic Link
• Host: Dr. Angela Poff
• Guest Speaker: Dr. Jeff Volek
• Topic: Exploring the keto-adapted phenotype, with a focus on muscle
• Guest Background: Registered dietitian, research scientist, pioneer in low-carb and ketogenic nutrition

Dr. Jeff Volek's Background and Contributions

• Professor at Ohio State University
• Contributed to science on ketones and ketogenic diets for two decades
• Focus on managing insulin resistance, optimizing human performance
• Over 200 lectures, more than 300 peer-reviewed publications
• Co-founder and former Chief Scientific Officer of Virta Health

Main Discussion: Keto Adaptation in Muscle

1. Glycogen Metabolism Under Keto-Adaption

   • Study Findings: Low-carb athletes maintain glycogen levels similar to high-carb athletes.
   • Glycogen breakdown rates: Similar in both diet groups.
   • Resynthesis without carbohydrate intake: Possible through recycling lactate, amino acids, and glycerol.
   • Hypothetical Pathways: Usage of lactate, pentose phosphate pathway for nucleotide synthesis.

2. Ketone Production in Muscle

   • Traditional View: Ketone production mainly in liver.
   • Recent Findings: Evidence that skeletal muscle may produce ketones, specifically through leucine breakdown.
   • Gene Expression: High expression of HMG-CoA synthase in keto-adapted athletes.

3. Ketones and Heart Function

   • Heart's Ketone Utilization: Increases with circulating ketone levels.
   • In Heart Failure: Ketone usage can improve cardiac function; sglt2 inhibitors and exogenous ketones show positive effects.
   • Studies: Infusion studies and exogenous ketone trials show improved cardiac output and function.
   • Current Research: Projects underway to explore long-term effects of ketogenic diets on heart function.

Supporting Evidence and Research

• Arterial-Venous Difference Studies: Conversion of acetoacetate to BHB in muscle suggests utilization of ketones.
• Animal and Human Studies: Consistent results in improved cardiac function with ketone use.

Future Directions and Research Needs

• Understanding Glycogen Synthesis: More research needed on glycogen repletion without carbohydrate intake.
• Long-term Effects: Studies on sustained effects of ketosis on heart and muscle function.

Conclusion

• Potential Benefits: Underappreciated beneficial effects on muscle and heart function with nutritional ketosis.
• Acknowledgments: Thanks to lab members, collaborators, and sponsors.

Outro

• Encouragement to join the Metabolic Initiative for more in-depth content.
• CMEs available for healthcare professionals through the platform.