O049 - FEMALES HAVE LOWER OVERALL ANABOLIC RESPONSE TO PROTEIN INTAKE REGARDLESS OF PROTEIN QUALITY
O049
FEMALES HAVE LOWER OVERALL ANABOLIC RESPONSE TO PROTEIN INTAKE REGARDLESS OF PROTEIN QUALITY
S. B. Knezek1,*, M. C. Kang1, S. S. Malireddy1, R. A. Wierzchowska-McNew1, M. P. Engelen1, N. E. Deutz1 on behalf of Center for Translational Research in Aging and Longevity
1Texas A&M University, College Station, United States
Rationale: We previously found sex-specific postabsorptive amino acid metabolic profiles, but the effect of biological sex on the metabolic response to dietary protein is unknown. Using a novel stable-isotope pulse, we compared whey (WP), soy (SP), and pea (PP) protein in older adults to investigate if biological sex affects intracellular anabolism (net protein synthesis (NetPS)) and essential/nonessential amino acid (EAA/NEAA) disposal.
Methods: 32 older adult participants (20m/12f), age (55-90y) participated in a randomized single blind crossover design over four non-consecutive study days. They consumed 45g of whey protein (WP), soy protein (SP), pea protein (PP), or water (postabsorptive state) via sip feeding every 20 minutes for 5 hours. 3 hours into feeding, an intravenous (IV) administration of a stable-isotope pulse containing amino acids to assess prandial amino acid kinetics and intracellular anabolic responses. Blood samples were collected pre/post pulse, and tracer enrichment was analyzed by LC-MS/MS. Data are mean (µmol/min) [95% CI], stats by GLMM with lean body mass, sex, and age as fixed effects.
Results: Females (f) show a lower NetPS than males (m)(p=0.004), regardless of protein (WP: m=105% [84, 126], f=90% [71, 109]; SP: m=100% [85, 115]m, f=87% [73, 100]; PP: m=72% [61, 83], f=62% [51, 72]). Intracellular disposal of the EAAs phenylalanine (p=0.005) and tryptophan (p=0.004), and NEAA proline (p<0.001) was reduced in females compared to males, regardless of the type of protein consumed.
Conclusion: Biological sex distinctly affects the intracellular amino acid response to dietary proteins in older adults, using a novel stable-isotope pulse with compartmental analysis. Female older adults show a distinct reduction in intracellular anabolic response than their male counterparts, regardless of protein source, suggesting different (sex specific) protein needs for anabolism
Disclosure of Interest: S. Knezek: None declared, M. Kang: None declared, S. Malireddy: None declared, R. Wierzchowska-McNew: None declared, M. Engelen: None declared, N. Deutz Grant / Research Support from: WoodNext Foundation