Research Article Circulating Interleukin-6 (but Not Other Immune Mediators) Associates with Criteria for Fried’s Frailty among Very Old Adults Gilberto Santos Morais Junior , 1 Diego Ignacio Valenzuela Perez , 2 Audrey Cec´ ılia Tonet-Furioso , 3 Lucy Gomes, 3 Karla Helena Coelho Vilaça , 3 Vicente Paulo Alves , 3 Clayton Franco Moraes , 1,3 and Ot´ avio Toledo N´ obrega 1,4 1 Health Faculty, Campus Universit´ ario Darcy Ribeiro, Universidade de Bras´ ılia, Bras´ ılia, DF, Brazil 2 Kinesiology School and Physical Activity and Sports Science Master Program, Universidad Santo Tom´ as, Puerto Montt, Chile 3 Graduate Program in Gerontology, Campus Taguatinga, Universidade Cat´ olica de Bras´ ılia, Bras´ ılia, DF, Brazil 4 Division of Geriatric Medicine, Department of Medicine, McGill University, 1001 Boul D´ ecarie, Montreal, QC, Canada Correspondence should be addressed to Ot´ avio Toledo N´ obrega; otnobrega@gmail.com Received 3 June 2020; Revised 8 October 2020; Accepted 22 October 2020; Published 4 November 2020 Academic Editor: Giulia Accardi Copyright © 2020 Gilberto Santos Morais Junior et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background and Aim. Frailty is a geriatric condition resulting from physiological changes covering the musculoskeletal, immune, and neuroendocrine systems, leading to a greater inflammatory state. e present research aimed to investigate the association of components of Fried’s frailty (as well as of the phenotype as a whole) with total serum levels of a panel of inflammatory mediators. Methods. One hundred and sixty-one very old patients (aged ≥80 years) devoid of cognitive decline were eligible for analyses. Clinical and biochemical data along with physical and cognitive assessments encompassing dual-energy X-ray scans and hand dynamometry were adopted to investigate frailty criteria, while circulating immune mediators (IFNc, IL-2, IL-4, IL-6, IL-10, and TNFα) were assessed using high-throughput flow cytometry. Results. Preliminarily, IL-6 correlated positively with waist-to-hip ratio and C-reactive protein and negatively with glycemia. In analyses controlled for these factors, serum levels of IL-6 were comparatively augmented among the very old participants with reduced grip strength (OR � 3.299; 95% CI 1.08–6.09; p � 0.032) and among those with slow walk speed (OR � 2.460; 95% CI 1.16–7.05; p � 0.022). Conclusions. Our study shows a strong negative correlation of IL-6 levels with Fried’s frailty components of grip strength and walk speed in very old adults, regardless of confounding factors. 1. Introduction e aging process is responsible for dysfunctions in skeletal muscles, strength, and bone mass and increases the risk of disability especially among very old adults [1–3]. Frailty is a geriatric condition resulting from physiological changes that affect the musculoskeletal, immune, and neuroendocrine systems [4], leading to functional decline in elderly pop- ulation and increasing prevalence of chronic degenerative diseases, depression, and mortality [5–7]. Studies point to a greater risk of negative events in terms of health and functionality among the very old (≥80 years) subset of older individuals with the syndrome, with evidence that frailty in this stratum contributes to increased mortality related to falls [8, 9]. Despite that, the fundamental char- acteristics of frailty are well established on the basis of declines in lean body composition as well as loss in muscular endurance and performance, and the pathophysiological changes that underlie this clinical entity are still not well understood. In this context, a process entitled as “inflam- mageing” that usually refers to slightly, subclinically higher levels of serum immune mediators in older adults relative to youngsters, both groups devoid of overt infectious disease, is associated with the pathophysiology of chronic conditions such as frailty [10–12] and susceptibility to infectious ill- nesses such as COVID-19 [13]. Enhanced levels of circulating Hindawi Journal of Aging Research Volume 2020, Article ID 6831791, 8 pages https://doi.org/10.1155/2020/6831791