(P18-045-24) Differences in Inflammatory and Nutritional Biomarkers in Community Dwelling Older Adults With and Without Sarcopenia

Objectives: To examine differences in biomarkers of inflammation and nutrition status between sarcopenic and non-sarcopenic older adults.

Methods: Twenty-one older adults were categorized as non-sarcopenic (age= 73.1 ± 6.2 years, n=5 males, n=5 females) and sarcopenic (age= 81.2 ± 10.5 years, n=6 males, n=5 females), based on the European Working Group on Sarcopenia in Older People criteria, using muscle mass (dual energy x-ray absorptiometry) and grip strength (dynamometer). Fasted venous blood (plasma) were analyzed using a multi-analyte platform to determine concentrations of 37 inflammatory markers (cytokines, receptors and immune biomarkers). Nutritional biomarkers measured by ELISA included plasma 25(OH)Vitamin D, ferritin, transferrin, hemoglobin, insulin growth factor-1 (IGF-1) and serum iron and total iron binding capacity. Independent samples t-tests examined group differences in markers (means ± standard deviations).

Results: Sarcopenic individuals had 45% and 89% higher concentrations of inflammatory proteins- interleukin-1 receptor antagonist (IL-1ra) and macrophage inflammatory protein-1beta (MIP-1β), respectively, compared to non-sarcopenic individuals (p=0.038 – 0.043). Non-sarcopenic individuals had 46% higher IGF-1 concentrations than sarcopenic individuals (144.97 vs. 99.02 ng·mL^-1, p=0.015). While there were no significant group differences for nutritional biomarkers, deficiencies in iron and vitamin D were more prevalent with sarcopenia, with 80% of sarcopenic females vitamin D deficient (18.7 ± 4.7 ng·mL^-1) compared to 40% of non-sarcopenic females (46.6 ± 32.0 ng·mL^-1). Sarcopenic males were vitamin D insufficient (36.8 ± 26.1 ng·mL^-1) while non-sarcopenic males were vitamin D sufficient (50.7 ± 49.2 ng·mL^-1). Additionally, 36% of sarcopenic individuals were iron deficient (ferritin < 35 ng·mL^-1) compared to 10% of non-sarcopenic individuals.

Conclusions: Sarcopenic individuals exhibit higher levels of some inflammatory markers and lower levels of IGF-1 that may contribute to muscle loss. In addition, nutrients linked to strength/function such as vitamin D and iron were lower in sarcopenic individuals. Nutritional strategies targeting inflammation and nutrient status could help mitigate sarcopenia progression.

Funding Sources: This study was funded by Abbott Nutrition and partly by the Hatch Act (USDA).