Bioimpedance-Estimated Metabolic Age in a Falls Clinic: Associations with Multimorbidity and Physical Frailty

As the number of community-dwelling older adults continues to increase and falls presentations become more common in clinical practice, there is a pressing need for strategies to assess risk and implement evidence-based interventions 1 .However, advancing chronological age (CA) does not always reflect unhealthy ageing; instead, an individual's biological age is more influenced by factors such as metabolism, morbidities 2 , frailty, and body composition 3 .In the falls clinic, alongside the evaluation of factors such as comorbidities, frailty, and functionality, assessing body composition could be important because muscle mass, fat distribution, and sarcopenia can influence balance, strength, and overall falls risk 1,4 .Bioelectrical impedance analysis (BIA) is a non-invasive method used in some clinical and research settings to estimate body composition and also readily provides a BIA-based estimate of an individual's metabolic age (MA) 5 .BIA-estimated MA has been associated with factors such as: waist-to-height ratio 6 ; physical activity, adherence to the Mediterranean diet, and socioeconomic class 7 .However, the clinical significance of this MA estimate remains poorly understood in the falls clinic and it is not clear if it should be used for patient feedback in clinical practice.To address this gap, this study investigated the clinical associations of BIA-estimated MA in older attendees of a falls clinic.Specifically, it examined differences between Abstract Bioelectrical impedance analysis (BIA) is a non-invasive method used to assess body composition and estimate metabolic age (MA).However, the clinical significance of BIA-estimated MA remains poorly understood.We explored the associations of MA with chronological age (CA), multimorbidity, and physical frailty (PF) in falls clinic attendees.Participants aged 50 years were assessed for multimorbidity using the Cumulative Illness Rating Scale-Geriatric, PF using the SHARE Frailty Instrument for Primary Care, and underwent BIA.Among 107 participants (mean age 69.8 years, 57% women), MA showed a moderate correlation with CA (r=0.62,p<0.001).On bivariate analysis, participants with MA>CA were younger, had higher multimorbidity, and were frailer compared to those with MA<CA.Multivariate linear regression analyses revealed that MA was independently associated with CA and BIA-estimated fat mass in both sexes, BIA-estimated muscle mass in men, and PF in women, but not with multimorbidity.BIAestimated MA mostly reflects CA and BIA's own body composition estimates, but was significantly associated with PF in women.Research should externally validate this finding and investigate the responsiveness of BIA-estimated MA to interventions.