(OR06-05-24) Post-absorptive Myofibrillar Protein Synthesis Differs Between Pre- and Post-menopausal Females

Saturday, June 29, 2024

5:48 PM – 6:00 PM CT

Location: W183

Presenting Author(s)

Žan Zupančič, MSc (he/him/his)

Graduate Student
University of Illinois Urbana-Champaign
Urbana, Illinois, United States

Disclosure(s): No relevant financial relationship(s) with ineligible companies to disclose.

Co-Author(s)

AA

Andrew T. Askow, MS

University of Illinois at Urbana-Champaign
Urbana, Illinois, United States
JB

Joseph W. Beals

University of Illinois Urbana-Champaign, United States
Nicholas A. Burd, PhD

Associate Professor
University of Illinois Urbana-Champaign
Urbana, Illinois, United States
RJ

Ralf Jäger

Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, United States
ZL

Zhong Li, PhD

University of Illinois at Urbana-Champaign
Urbana, Illinois, United States
CM

Colleen F. McKenna

University of Colorado Anschutz Medical Campus, United States
KP

Kevin J. Paulussen, MS

University of Illinois at Urbana-Champaign
Urbana, Illinois, United States
MP

Martin Purpura

Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, United States
AS

Amadeo F. Salvador

University of Illinois Urbana-Champaign, United States
AU

Alexander V. Ulanov, PhD

University of Illinois at Urbana-Champaign
Urbana, Illinois, United States

Objectives: Elevated postabsorptive myofibrillar protein synthesis (MPS) rates have been associated with reduced anabolic sensitivity to feeding and exercise stimuli. To date, age-related muscle protein turnover investigations have used male participants. Consequently, the influence of age on the regulation of muscle protein turnover is still relatively unstudied among females. This study aimed to compare postabsorptive MPS between pre- and post-menopausal females.

Methods: Postabsorptive MPS were compared between fourteen healthy pre-menopausal females (24±3y, 24.9±3.1 BMI) and sixteen healthy post-menopausal females (60±8y, 26±4 BMI). In pre-menopausal postabsorptive females, MPS was determined from two different clinical trials (NCT02613767 and NCT03870165) using a sequential biopsy approach during primed continuous L-[ring-¹³C₆]phenylalanine [n = 9] and/or L-[ring-²H₅]phenylalanine [n =5] infusions. In post-menopausal females, postabsorptive MPS were determined from a single clinical trial (NCT02918981) using single biopsy and sequential biopsy approaches during primed continuous L-[ring-¹³C₆]phenylalanine infusion. Differences in myofibrillar FSR were assessed via linear mixed-effects models with leg, time, and group as fixed factors with Bonferroni correction.

Results: Postabsorptive MPS were 37% higher in post-menopausal females compared to pre-menopausal females (P=0.023). There were no observed differences in postabsorptive MPS between the single biopsy and sequential biopsy approaches in post-menopausal females (0.077±0.029 vs. 0.081±0.035; P = 0.763).

Conclusions: Post-menopausal females demonstrated elevated post-absorptive MPS compared to pre-menopausal females. These results suggest that aging females may be more susceptible to age-related anabolic resistance vs. their aging male counter-parts.

Funding Sources: This study was supported by Increnovo, LLC., The National Pork Board and USDA National Institute of Food and Agriculture.