Multivariable analysis of myokines as biomarkers of frailty in females

BACKGROUND: Individuals living with frailty have reduced physiological reserve for tolerating health stressors. Myokines are cytokines released from skeletal muscle that have pleiotropic effects throughout the body. Suggested as a means of facilitating earlier identification of frailty, little research has explored the association of myokines with frailty status. METHODS: This secondary, cross-sectional analysis of the Women's Advanced Risk Assessment in Manitoba (WARM) Hearts observational cohort comprised of females aged 55 years or older (NCT03938155). Frailty was assessed using a frailty index (FI) and the Fried frailty phenotype (FP). Systemic myokine blood concentrations were quantified using the MILLIPLEX® Map Human Myokine Magnetic Bead Panel. Cohort characteristics and myokine concentrations by frailty status were assessed using ANOVAs. Stepwise multivariable regression examined the value of adding myokines to a model identifying the FI and then FP score after adjusting for age. RESULTS: The mean (± SD) age of the cohort was 64 ± 6 years (n = 329). The FI identified 28 robust females, 248 living with pre-frailty and 53 living with frailty. The stepwise multivariable regression adjusting for age included BDNF (β 0.143, SE 0.013), FABP-3 (β 0.149, SE 0.020), OSM (β 0.144, SE 0.005) and OSTN (β -0.197, SE 0.010) in the model for the FI. Only SPARC (β 0.121, SE 0.107) was included in the final stepwise multivariable regression model for FP. CONCLUSION: BDNF, FABP-3, OSM and OSTN contributed to a stepwise regression model predicting the FI after adjusting for age, whereas only SPARC remained in a model predicting FP score.