Polymeris AA, Helfenstein F, Benkert P, Aeschbacher S, Leppert D, Coslovsky M, Willemse E, Schaedelin S, Blum MR, Rodondi N, Reichlin T, Moschovitis G, Wuerfel J, De Marchis GM, Engelter ST, Lyrer PA, Conen D, Kühne M, Osswald S, Bonati LH, and Kuhle J
Objective: Serum neurofilament light chain (sNfL) is increasingly used as a neuroaxonal injury biomarker in the elderly. Besides age, little is known about how other physiological factors like renal function and body mass index (BMI) alter its levels. Here, we investigated the association of estimated glomerular filtration rate (eGFR) and BMI with sNfL in a large sample of elderly patients with atrial fibrillation (AF)., Methods: This is a cross-sectional analysis from the Swiss-AF Cohort (NCT02105844). We measured sNfL using an ultrasensitive single-molecule array assay. We calculated eGFR using the chronic kidney disease epidemiology collaboration (CKD-EPI) creatinine (eGFR crea ) and creatinine-cystatin C (eGFR crea-cys ) formulas, and BMI from weight and height measurements. We evaluated the role of eGFR and BMI as determinants of sNfL levels using multivariable linear regression and the adjusted R 2 (R 2 adj )., Results: Among 2,277 Swiss-AF participants (mean age 73.3 years), eGFR crea showed an inverse curvilinear association with sNfL after adjustment for age and cardiovascular comorbidities. BMI also showed an independent, inverse linear association with sNfL. The R 2 adj of models with age, eGFR crea , and BMI alone was 0.26, 0.35, and 0.02, respectively. A model with age and eGFR crea combined explained 45% of the sNfL variance. Sensitivity analyses (i) further adjusting for vascular brain lesions ( N = 1,402 participants with MRI) and (ii) using eGFR crea-cys yielded consistent results., Interpretation: In an elderly AF cohort, both renal function and BMI were associated with sNfL, but only renal function explained a substantial proportion of the sNfL variance. This should be taken into account when using sNfL in elderly patients or patients with cardiovascular disease., Competing Interests: GM: consultant fees from Astra Zeneca, Bayer, Boehringer-Ingelheim, Novartis, outside of the submitted work. GMDM: Support from SNSF, “Spezialprogramm Nachwuchsförderung Klinische Forschung,” University of Basel, Science Funds (Wissenschaftspool) University Hospital Basel, Swiss Heart Foundation, Bangerter-Rhyner-Stiftung, Swisslife Jubiläumsstiftung for Medical Research, Swiss Neurological Society, Fondazione Dr. Ettore Balli, De Quervain research grant, Thermo Fisher GmbH; Travel honoraria Bayer, BMS/Pfizer; Speaker honoraria Bayer, Medtronic; Steering committee PACIFIC Stroke, Industry payments to the research fund of the University Hospital Basel. SE: Travel or speaker honoraria from Bayer, Boehringer-Ingelheim, Daiichi-Sankyo; Scientific advisory boards Bayer, Boehringer-Ingelheim, BMS/Pfizer, MindMaze; Editorial board of Stroke; Research funding to his institutions from Pfizer, Stago, Daiichi-Sankyo, Science Funds [Wissenschaftsfonds] University Hospital Basel, University Basel, “Wissenschaftsfonds Rehabilitation” University Hospital for Geriatric Medicine Felix Platter, “Freiwillige Akademische Gesellschaft Basel,” Swiss Heart Foundation, SNSF. DC: consulting fees from Roche Diagnostics, outside of the current work. MK: fees from Bayer, Boehringer-Ingelheim, BMS/Pfizer, Daiichi-Sankyo, Medtronic, Biotronik, Boston Scientific, Johnson&Johnson, Roche; grants from Bayer, Pfizer, Boston Scientific, BMS, Biotronik, Daiichi-Sankyo. LB: fees and non-financial support from Amgen, Bayer; fees from BMS, Claret Medical and InnovHeart; grants from AstraZeneca, SNSF, University of Basel, Swiss Heart Foundation, outside the submitted work. JK: speaker fees, research support, travel support, and/or advisory boards Swiss Multiple Sclerosis Society, SNSF, University of Basel, Progressive Multiple Sclerosis Alliance, Bayer, Biogen, Celgene, Merck, Novartis, Octave Bioscience, Roche, Sanofi. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Polymeris, Helfenstein, Benkert, Aeschbacher, Leppert, Coslovsky, Willemse, Schaedelin, Blum, Rodondi, Reichlin, Moschovitis, Wuerfel, De Marchis, Engelter, Lyrer, Conen, Kühne, Osswald, Bonati, Kuhle and the Swiss-AF Investigators.)