Association between frailty and serum biomarkers in older adults

Objective To investigate the relationship between frailty and serum biomarkers in the elderly. Methods A total of 371 elderly individuals aged 60 years and above with complete medical data were recruited during health examinations.Frailty phenotype assessment and comprehensive geriatric assessment were conducted.Serum levels of interleukin-6(IL-6), high sensitivity C-reactive protein(hs-CRP), tumor necrosis factor-α(TNF-α), homocysteine(Hcy), insulin-like growth factor-1(IGF-1), 25-hydroxyvitamin D[25(OH)D], folic acid and vitamin B12(VitB12)were detected by enzyme-linked immunosorbent assays(ELISA)and chemiluminescence immunoassays.Associations between frailty and the above factors were analyzed. Results Serum levels of IL-6, TNF-α, Hcy and IGF-1 were significantly elevated along with progressive increase in frailty severity(all P 0.05). Logistic regression analysis showed that, after adjusting for age, gender, body mass index(BMI)and some clinical aspects(hearing loss, urinary incontinence, pain, malnutrition, cognitive dysfunction, decreased activities of daily living, depression, insomnia, and anemia), serum levels of IL-6(OR=1.012, 95%CI=1.005-2.041, P=0.033), IGF-1(OR=1.017, 95%CI=1.011-1.118, P=0.021)and Hcy(OR=1.007, 95%CI: 1.002-1.073, P=0.047)were significantly associated with frailty status. Conclusions Serum levels of IL-6, Hcy and IGF-1 are related to frailty status and may be used as potential biomarkers for the assessment of frailty in older adults. Key words: Frailty; Biomarkers; Inflammation; Insulin-like growth factor; Homocysteine; 25(OH)D; Folate