Abstract
Background
Research suggests that hearing loss in older adults is associated with elevated neuroinflammation and neurodegeneration, both of which are risk factors for dementia. In a secondary analysis of the Aging and Cognitive Health Evaluation in Elders (ACHIEVE) randomised controlled trial (ClinicalTrials.gov identifier: NCT03243422), we examined if hearing intervention slowed 3-year change in blood-based biomarkers of neuroinflammation (glial fibrillary acidic protein [GFAP]) and neurodegeneration (neurofilament light chain [NfL]).
Methods
ACHIEVE, a clinical trial in the United States conducted between January 4, 2018 and November 30, 2022, tested the effects of hearing intervention (audiological counselling, provision of hearing aids) versus health education control (counselling on chronic disease prevention) on 3-year cognitive decline among older adults without substantial cognitive impairment and with untreated hearing loss. Plasma was collected at baseline and three years later among ACHIEVE participants recruited from the Atherosclerosis Risk in Communities cohort. Covariate-adjusted linear mixed effects models estimated intention-to-treat effects on 3-year change in inverse-normal transformed values of GFAP and NfL.
Findings
Participants in the analytic sample (n = 164) were mean (SD) age 78.1 (2.9) years, 64.0% female, and 73.2% White. Over three years, hearing intervention was associated with a slower rise in GFAP (intervention: −0.026; 95% CI: −0.144, 0.093, control: 0.149; 95% CI: 0.039, 0.260; difference: −0.175; 95% CI: −0.322, −0.028; p-difference: 0.019) and NfL (intervention: 0.171; 95% CI: 0.022, 0.319, control: 0.330; 95 %CI: 0.185, 0.475, difference: −0.159; 95 %CI: −0.348, 0.029; p-difference: 0.098).
Interpretation
Randomisation to hearing intervention was associated with a slower three-year rise in a blood-based biomarker of neuroinflammation. Comparable estimates were observed for neurodegeneration, although the effect was not statistically significant. Findings suggest that hearing intervention may reduce the rate of change in non-specific blood-based biomarkers associated with brain health and dementia progression.
Authors and Affiliations
James Russell Pikeᵃ˒ᵇ˒ʳ, Alison R. Huangᵉ˒ᶠ˒ʳ, Nicholas Reedᵃ˒ᵇ, Michelle L. Arnoldᵈ˒ᵖ, Theresa H. Chisolmᵈ˒ᵖ, David Couperᶜ, Jennifer A. Dealᵉ˒ᶠ˒ᵍ, Sarah Faucetteˡ, Adele M. Gomanʰ, Rebecca F. Gottesmanⁱ, Timothy M. Hughesʲ, David Knopmanᵏ, Christine Mitchellᵉ˒ᶠ, Thomas H. Mosleyˡ, Priya Paltaᵐ, James S. Pankowⁿ, Victoria A. Sanchezᵈ˒ᵖ, Elizabeth Selvinᵉ˒ᵒ, Kevin J. Sullivanˡ, Bharat Thyagarajanⁿ, Lynne E. Wagenknechtᑫ, Frank R. Linᵉ˒ᶠ˒ᵍ, and Josef Coreshᵃ˒ᵇ
ᵃ Department of Medicine, New York University Grossman School of Medicine, New York, NY, USA
ᵇ Department of Population Health, New York University Grossman School of Medicine, New York, NY, USA
ᶜ Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
ᵈ Department of Communication Sciences & Disorders, College of Behavioral & Community Sciences, University of South Florida, Tampa, FL, USA
ᵉ Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
ᶠ Cochlear Center for Hearing and Public Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
ᵍ Department of Otolaryngology-Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, MD, USA
ʰ School of Psychology, University of Leeds, UK
ⁱ National Institute of Neurological Disorders & Stroke Intramural Research Program, National Institutes of Health, Bethesda, MD, USA
ʲ Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
ᵏ Department of Neurology, Mayo Clinic, Rochester, MN, USA
ˡ The MIND Center, University of Mississippi Medical Center, Jackson, MS, USA
ᵐ Department of Neurology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
ⁿ Division of Epidemiology and Community Health, University of Minnesota School of Public Health, Minneapolis, MN, USA
ᵒ Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins University, Baltimore, MD, USA
ᵖ Department of Otolaryngology-Head & Neck Surgery, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
ᑫ Department of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC, USA