Cognitive Impairment and Hearing Loss in the Rio Grande Valley: A Retrospective Study of Alzheimer's, Dementia, and Mild Cognitive Impairment

Background: Millions of US adults experience underrecognized hearing loss, despite effective treatments. Interestingly, hearing loss has been suggested to be further exacerbated in populations of Alzheimer’s Disease. It is hypothesized that structural and functional features of auditory brain organization, which make it vulnerable to neurodegeneration, may heighten susceptibility to hearing loss, although it is unclear how ethnicity impacts its epidemiology. Here, we sought to address this gap by exploring the association between self-reported hearing loss and cognitive decline in Hispanic and non-Hispanic patients across the Rio Grande Valley (RGV). Methods: We conducted a retrospective review of the UTHealth RGV electronic medical record system for participants who had an ICD-10 code for Alzheimer's disease, dementia, or mild cognitive impairment. For all charts, we noted if patients self-reported hearing loss and also collected demographics (e.g. ethnicity) and clinical characteristics, including diagnosis of type 2 diabetes mellitus, prediabetes, and primary hypertension. Patient charts were excluded if they had neurocognitive disorders and/or diagnoses not related to clinically relevant hearing loss. Statistical analyses were performed to evaluate differences between Hispanic and non-Hispanic subject groups using SAS, where p<0.05 was defined as significant. Results: We reviewed 6,047 medical charts spanning 01/2019-01/2024. The participant pool achieved near-equal gender distribution with 49.3% (n=2,981) females and 50.7% (n=3,066) males. The average participant age was 55.3 years old, with a median age of 64 years. Geographically, the majority (50%, n=3,029) resided in Hidalgo County. High self-reported hearing loss was observed, with 90% (n=2,700) of females and 94% (n=2,877) of males having hearing loss. A subsample of 479 participants underwent cognitive screening, revealing a trend of females being more prevalent in dementia (62%, n=175) and Alzheimer's disease diagnoses (63%, n=60). This study explored the association between self-reported hearing loss and various health conditions. Among participants with hearing loss, some also reported cognitive decline, including dementia (n=2), Alzheimer's disease (n=3), and mild cognitive impairment (n=12). Additionally, an examination of metabolic conditions revealed a co-occurrence of hearing loss with prediabetes (n=12), type 2 diabetes mellitus (n=83), and primary hypertension (n=153). Conclusion: This study highlights a high prevalence of self-reported hearing loss in a Hispanic population across the RGV. While it suggests a possible link between hearing loss and some cognitive decline cases, the retrospective design limits causal inference. Future prospective studies with larger, Hispanic cohorts and objective hearing assessments are crucial to explore these relationships further. Investigating the co-occurrence of hearing loss with metabolic conditions also warrants further research.