P1043 - TWO WEEKS OF PROTEIN SUPPLEMENTATION DOES NOT INCREASE DAILY MUSCULOSKELETAL TISSUE PROTEIN SYNTHESIS RATES IN VIVO IN HUMANS

P1043

TWO WEEKS OF PROTEIN SUPPLEMENTATION DOES NOT INCREASE DAILY MUSCULOSKELETAL TISSUE PROTEIN SYNTHESIS RATES IN VIVO IN HUMANS

D. C. J. Houtvast^1,*, F. K. Hendriks¹, M. E. G. Weijzen¹, A. H. Zorenc¹, J. S. J. Smeets¹, P. J. Emans², W. K. W. H. Wodzig³, M. S. Larsen⁴, U. R. Mikkelsen⁴, M. G. M. Schotanus⁵, B. Boonen⁵, J. M. J. van Mulken⁶, P. A. J. de Leeuw⁷, M. F. M. van Stijn⁸, K. Baar^1,9,10, L. J. C. van Loon¹

¹Department of Human Biology, Institute of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre+, ²Department of Orthopaedics, Joint Preserving Clinic, Maastricht University Medical Centre+, ³Central Diagnostic Laboratory, Maastricht University Medical Centre+, Maastricht, Netherlands, ⁴Arla Foods Ingredients Group P/S, Viby J, Denmark, ⁵Department of Orthopaedic Surgery, Zuyderland Medical Center, Sittard-Geleen, ⁶Department of Orthopaedic Surgery, Laurentius Ziekenhuis, Roermond, ⁷Department of Orthopaedic Surgery, Flevoziekenhuis, Almere, ⁸Department of Anaesthesiology, Amsterdam UMC, Amsterdam, Netherlands, ⁹Department of Neurobiology, Physiology and Behavior, University of California Davis, ¹⁰Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, United States

Rationale: The plasticity of musculoskeletal tissues other than muscle, and whether these tissues are responsive to the anabolic properties of protein supplementation, is poorly understood. This study assessed skeletal muscle, bone, cartilage, tendon, ligament, meniscus, and periarticular soft tissue protein synthesis rates during a two-week period with or without protein supplementation in vivo in humans.

Methods: Twenty-four otherwise healthy adults (12M/12F; age: 68±7 y; BMI: 29±5 kg/m²) undergoing total knee arthroplasty were randomly allocated to maintain their habitual diet (n=12) or to consume an additional 40 g whey protein isolate daily for 14 days prior to surgery (n=12). Deuterium oxide administration throughout the 14-day preoperative period and tissue collection during surgery allowed the assessment of protein synthesis rates of numerous musculoskeletal tissues.

Results: Fractional protein synthesis rates in muscle, synovium, and Hoffa’s fat pad averaged 1.17±0.27, 0.76±0.39, and 0.53±0.33%/d, respectively. Fibrous tissues, including anterior and posterior cruciate ligament, patellar tendon, lateral and medial meniscus, and femoral cartilage presented protein synthesis rates of 0.43±0.23, 0.47±0.35, 0.19±0.10, 0.21±0.14, 0.18±0.14, and 0.19±0.12%/d, respectively. Finally, bone tissue obtained from the femur, notch, trochlea, tibial plateau, and patella showed protein synthesis rates of 0.18±0.13, 0.21±0.15, 0.13±0.11, 0.12±0.06, and 0.16±0.10%/d, respectively. Tissue protein synthesis rates did not differ between the control and protein supplemented group (independent samples t-tests, all tissues P>0.05).

Conclusion: Daily muscle, bone, cartilage, tendon, ligament, meniscus, and periarticular soft tissue protein synthesis rates range between 0.12 and 1.17%/d in vivo in humans. Two weeks of protein supplementation does not increase daily musculoskeletal tissue turnover.

Disclosure of Interest: D. Houtvast: None declared, F. Hendriks: None declared, M. Weijzen: None declared, A. Zorenc: None declared, J. Smeets: None declared, P. Emans: None declared, W. Wodzig: None declared, M. Larsen Other: MSL is an employee of Arla Foods Ingredients and was involved in designing the study. Arla Foods Ingredients provided the protein supplement and partially funded the work presented., U. Mikkelsen Other: URM is an employee of Arla Foods Ingredients and was involved in designing the study. Arla Foods Ingredients provided the protein supplement and partially funded the work presented., M. Schotanus: None declared, B. Boonen: None declared, J. van Mulken: None declared, P. de Leeuw: None declared, M. van Stijn: None declared, K. Baar: None declared, L. van Loon: None declared