Association between self-reported sensory impairments and low cognitive performance in older adults: A cross-sectional study based on National Health and Nutrition Examination Survey (NHANES)

Abstract

Background

Early identification of risk factors is vital for the control of cognitive degenerative diseases, and sensory impairments could be potential candidate indicators.

Objective

To determine whether self-reported hearing loss (HL), olfactory dysfunction (OD), and gustatory dysfunction (GD) are associated with low cognitive performance.

Methods

Cross-sectional data from the 2011–2012 National Health and Nutrition Examination Survey (NHANES) were used. Data on participants’ subjective hearing ability, olfactory and gustatory status were obtained from corresponding questionnaire datasets. Cognitive function was measured by the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST). The lowest quartile score of the four tests was used as the cutoff value to indicate low cognitive performance. Univariate and multivariate logistic regression analyses were conducted to investigate the association between sensory impairments and cognitive decline.

Results

The data of 1416 adults aged ≥60 years were included. Univariate logistic regression analyses showed that the association between self-reported HL, OD, GD, and low cognitive performance was significant across all four cognition tests. Multiple models of multivariate logistic regression adjusted by covariate factors were established and showed significant association between self-reported HL, OD, GD, and low cognitive performance.

Conclusions

Self-reported hearing loss, olfactory and gustatory dysfunction demonstrated significant associations with impaired cognitive performance in older adults. Multiple sensory impairments may lead to progressively worse cognitive performance.

Keywords

Alzheimer's disease gustatory dysfunction hearing loss National Health and Nutrition Examination Survey olfactory dysfunction

Introduction

Globally, the aging population is expanding rapidly due to increased life expectancy, posing significant public health challenges. While older adults frequently experience age-related memory and cognitive decline, it is crucial to distinguish between normal neurological aging processes and pathological cognitive changes associated with neurodegenerative disorders.¹ As the population ages, cognitive deterioration progresses irreversibly and may eventually evolve into pathological cognitive impairment or dementia. Given the current absence of curative treatments, identifying modifiable risk factors is paramount for developing strategies to delay the onset of cognitive decline and slow its rate of progression.²

Sensory impairments, particularly hearing loss, olfactory dysfunction (OD), and gustatory dysfunction (GD), constitute significant clinical concerns in older adults due to their potential associations with cognitive decline and dementia pathogenesis.³ Hearing loss (HL) is a leading cause of years lived with disability globally, and its burden is expected to rise with population aging.⁴ Several studies have demonstrated that age-related HL correlates with accelerated cognitive deterioration, linking greater severity to faster multidomain deterioration and higher dementia risk.⁵ Meanwhile, chemosensory disorders present substantial clinical burdens, with national estimates indicating approximately 2.7 million and 1.1 million U.S. adults experiencing smell and taste impairments, respectively.⁶ The majority of age-related OD is noted to present as hyposmia or anosmia, and most age-related subjective GD is reported as alterations in taste and regional taste loss. This complexity arises from the intricate neural coding systems and central projections of cranial nerves VII, IX, and X, which mediate chemosensory signal processing.⁶ Emerging research have established OD as an independent predictor of cognitive decline, though current evidence linking GD to cognitive outcomes remains inconclusive.^7,8

The National Health and Nutrition Examination Survey (NHANES), established by the National Center for Health Statistics (NCHS), is conducted each year to assess the health and nutritional status of the participants in the U.S. population. The survey employs complex sampling methodology to annually recruit approximately 5000 participants from 15 geographically dispersed clusters.⁹ NHANES collected data from hearing and chemosensory tests and questionnaires in specific years, as well as cognitive function data from their older adult participants. In this study, our objective was to investigate whether self-reported HL, OD, and GD among older adults are associated with low cognitive performance based on the data obtained from the NHANES.

Methods

Study sample

The NHANES combines interviews, physical examinations and laboratory examinations to collect health-related information in the U.S. general population. The survey protocol was approved by the NCHS Ethics Review Board, and written informed consent was obtained from all participants. A series of NHANES datasets, related documentation, and detailed protocols are publicly accessible from the NHANES website (https://www.cdc.gov/nchs/nhanes/index.html). This study utilized data from the 2011–2012 NHANES cycle. Since sensory function questionnaires were administered to participants aged ≥40 years whereas cognitive assessments were restricted to those ≥60 years, our final analytical cohort exclusively comprised individuals aged 60 years or older who had complete data from both sensory evaluations (auditory, olfactory, and gustatory questionnaires) and cognitive function testing.

Self-reported sensory impairments

The NHANES audiometry questionnaires provide interview data on self-reported hearing status, hearing screening history, the use of hearing aids, and risk factors for hearing loss.¹⁰ The general condition of participants’ hearing ability (answered ‘with little/ moderate/ a lot of trouble’ or ‘deaf’) was used as the key criterion for defining self-reported HL. The NHANES chemosensory questionnaire included self-reported olfactory and/or gustatory abilities as well as abnormal symptoms, medical treatment and presence of olfactory and gustatory dysfunction risk factors.¹¹ A group of questions, which have demonstrated good test-retest reliability and criterion validity in prior research, were used to identify self-reported OD and/or GD: perceived olfactory problems within the past 12 months (answered ‘yes’), or phantom odor sensations (answered ‘yes’), or perceived changes in function since age 25 (answered ‘worse now’), perceived gustatory problems within the past 12 months (answered ‘yes’) and received treatment for olfactory/gustatory impairments within last 12 months (answered ‘yes’).¹² A positive response to any of the questions listed above was classified as self-reported OD and/or GD. Thus, participants reporting any of these conditions (HL, OD, or GD) were defined as having a self-reported sensory impairment.

Low cognitive performance

For the cycle 2011–2012, cognitive functioning assessments included three kinds of tests: Consortium to Establish a Registry for Alzheimer's disease (CERAD) Word Learning subtest, the Animal Fluency Test (AFT) and the Digit Symbol Substitution Test (DSST).¹³

The CERAD test evaluates immediate and delayed recall of new verbal information to assess memory ability, and it consisted of three consecutive learning trials and a delayed recall trial.¹⁴ For the learning trials, participants are instructed to read aloud 10 unrelated words once they are presented. Immediately following the presentation of the words, participants recall as many words as possible. The maximum score on each trial is 10. In NHANES, the delayed recall trial was administered after the AFT and DSST (after a delay of approximately 8–10 min) and also had a maximum score of 10.^15–18 In this study, the total (CERAD-T) score and delayed recall (CERAD-DR) score were included respectively. The AFT assesses categorical verbal fluency, a key component of executive function. In this test, participants were asked to name as many animals as possible within one minute and scoring one point for each correct answer.¹⁹ The total point was summarized as the final AFT score. The DSST was conducted using a paper form that has a key at the top containing 9 numbers paired with symbols. Participants have two minutes to copy the corresponding symbols in the 133 boxes that adjoin the numbers. The score is the total number of correct matches. As a part of the Wechsler Adult Intelligence Scale (WAIS III), the DSST test reflects the ability of processing speed, sustained attention, and working memory.²⁰

In this study, the lowest quartile of the CERAD-T, CERAD-DR, AFT and DSST was used as the cutoff value to indicate different types of low cognitive performance, which was consistent with the methods used in previously reported study, because of the absence of a gold standard on the cutoff for these tests.²¹ On the other hand, age is a well-established risk factor for cognitive decline, and a single pooled cutoff for all participants would be methodologically unsound as it would confound age-related decline with low performance. Thus we divided the participants into three age strata (60–69, 70–79 and ≥80), and used the lowest quartile within each age group as the cutoff to indicate low cognitive performance.²² For each test, participants were divided into two groups: the low performance group included those who scored lower than the cutoff value for their age group, and the normal performance group for the others. A standard z-score was computed, for each participant, based on the mean and standard deviation of each test. In order to reflect the overall cognitive function, a global cognitive score was calculated as the sum of each test's standard z-score, and the lowest quartile was also used to divide participants into the low performance group and the normal performance group.

Covariates

The demographic variables included age, gender, race, marital status, educational level and family income-to-poverty ratio. Marital status was categorized as currently married or unmarried. Educational level was classified as less than high school diploma or high school graduate/equivalent. Income-to-poverty ratio was stratified as below poverty threshold (<1) or at/above poverty level (≥1). Alcohol consumption patterns were assessed using NHANES standardized questionnaires, with heavy drinking defined as affirmative responses to consuming ≥4/5 drinks daily during any life period. Smoking status was determined through three mutually exclusive categories: current smoker (affirmative to “Do you now smoke cigarettes?”), former smoker (negative to current smoking but prior cigarette use), and never smoker (negative to both current smoking and lifetime consumption of ≥100 cigarettes). Self-reported drug use history (yes/no) was extracted from the NHANES drug use questionnaire. Physical activity levels were dichotomized per WHO Global Physical Activity Questionnaire guidelines into active (≥600 MET-minutes/week) and inactive groups.²³ Sensory impairment risk factors included: tinnitus history, cerumen impaction, ear canal stenosis, persistent cold/flu lasting for one year, persistent dry mouth in the past year, nasal congestion (past year) and/or with ≥2 sinusitis, tonsils and/or wisdom teeth removed, head/face/skull trauma. History of ear infection was not included due to data scarcity. For common diseases, the history of heart disease, stroke, hypertension, high cholesterol, diabetes mellitus were included. Depressive symptoms were assessed using patient health questionnaire (PHQ-9) aligned with the Diagnostic Statistical Manual of Mental Disorders (DSM)-V, with scores ≥10 indicating clinically significant symptoms.²⁴

Data analysis

Normally distributed continuous variables were described as means (± standard errors [SE]), while nonnormally distributed continuous variables were described using median and interquartile range (IQR). Categorical variables were expressed as proportions (SE). Firstly, to examine variations in variables among groups, we employed t test and survey Wilcoxon rank-sum test for continuous variables, and for groups of categorical data, the Fisher exact test was used for expected frequencies <5, otherwise the Chi-squared test was used. Then univariate associations between self-reported sensory impairments and low cognitive performances were assessed with binary logistic regression. Finally, logistic regression models were employed to explore the multivariate association between self-reported sensory impairments and low cognitive performances. Multiple adjusted models were constructed for each combination of sensory impairment and cognitive assessment, each model adjusting for a different set of covariates to provide a nuanced understanding of how these covariates influence the observed association. The crude model was adjusted for age only for its recognized strong association with impaired cognitive performance, and other covariates were included into the multiple models in batches. The results of each model were compared to assess the consistency of the effect estimates under varying levels of covariate adjustment, thereby providing insights into the robustness of the impact of sensory impairments on low cognitive performances. The results of the logistic regression models were presented as odds ratios (ORs) with 95% confidence intervals (CIs) and p-values. All statistical analyses were performed using the R software (version 4.2.2) with the survey package, along with MSTATA software (www.mstata.com). A two-sided p value less than 0.05 was set as the level of statistical significance.

Ethic approval and consent to participate

The NHANES cycles were approved by the CDC's National Center for Health Statistics (NCHS) Research Ethics Review Board (ERB) and all participants provided written informed consent. As this study utilizes publicly available, anonymized NHANES data, it does not require additional ethical review by the Ethics Committee of the authors’ institute.

Results

A total of 1416 participants from the NHANES 2011–2012 were included, with 715 females (54.8%) and 701 males (45.2%). Age distribution revealed 766 participants aged 60–69 years, 416 aged 70–79 years, and 234 aged ≥80 years. Demographic characteristics, including race, marital status, educational level, and family income-to-poverty ratio, are summarized in Table 1. Regarding sensory impairments, 543 participants reported HL, 332 reported OD, and 213 reported GD. The distribution of co-occurring impairments was as follows: 59 participants with concurrent HL, OD, and GD; 110 with combined HL and OD; 45 with HL and GD; 44 with OD and GD; 329 with only HL; 119 with only OD; and 65 with only GD.

Table 1.

Characteristics of study participants.

Characteristic	Overall, Unweighted N = 1416
Age
Mean ± SD	69 ± 7
Median (IQR)	68 (63, 74)
Age Strata
60–69 y	766 (56.6%)
70–79 y	416 (29.3%)
≥80 y	234 (14.1%)
Gender
Female	715 (54.8%)
Male	701 (45.2%)
Race
Other Race/Multi-Racial	25 (2.5%)
Mexican American	92 (2.6%)
Other Hispanic	167 (4.1%)
Non-Hispanic White	615 (79.2%)
Non-Hispanic Black	395 (8.5%)
Non-Hispanic Asian	122 (3.1%)
Education
Under High School Education	409 (17.2%)
Above or Equal to High School Education	1007 (82.8%)
Marital status
Currently Unmarried	658 (37.6%)
Currently Married	758 (62.4%)
Income to Poverty Ratio
Below Poverty (<1)	282 (11.0%)
At or Above Poverty (≥1)	1134 (89.0%)
Sensory Impairments
Hearing Loss
No	873 (61.5%)
Yes	543 (38.5%)
Olfactory Dysfunction
No	1084 (78.3%)
Yes	332 (21.7%)
Gustatory Dysfunction
No	1203 (87.2%)
Yes	213 (12.8%)
Number of Sensory Impairments
0	645 (46.6%)
1	513 (37.3%)
2	199 (12.6%)
3	59 (3.5%)
Risk Factors for Sensory Impairments
Tinnitus in Past Year
No	1242 (85.5%)
Yes	174 (14.5%)
Impacted Cerumen
No	1395 (98.4%)
Yes	21 (1.6%)
Ear Canal Stenosis
No	1399 (98.1%)
Yes	17 (1.9%)
Persistent Cold/Flu Last 1year
No	1330 (94.8%)
Yes	86 (5.2%)
Persistent Dry Mouth in Past 1year
No	1168 (83.8%)
Yes	248 (16.2%)
Nasal Congestion in Past 1year and/or ≥2 Sinusitis
No	808 (50.5%)
Yes	608 (49.5%)
Tonsils Removed
No	1005 (60.8%)
Yes	411 (39.2%)
Wisdom Teeth Removed
No	359 (25.0%)
Yes	1041 (74.3%)
Don't Know	16 (0.7%)
Head/Face/Skull Trauma
No	1148 (76.5%)
Yes	268 (23.5%)
Personal History and Common Diseases
Smoking History
Never	700 (49.5%)
Former Smoker	531 (38.7%)
Current Smoker	185 (11.8%)
History of Drug Use
No	1316 (93.6%)
Yes	100 (6.4%)
Heavy Drinker
No	1228 (88.7%)
Yes	188 (11.3%)
Depression Symptoms
No	1304 (94.6%)
Yes	112 (5.4%)
History of Heart Disease
No	1186 (83.4%)
Yes	230 (16.6%)
History of Stroke
No	1316 (94.1%)
Yes	100 (5.9%)
History of Hypertension
No	496 (39.4%)
Yes	920 (60.6%)
History of High Cholesterol
No	299 (18.7%)
Yes	1117 (81.3%)
History of Diabetes Mellitus
Yes	368 (20.9%)
No	1048 (79.1%)
Physical Activity Group
Inactive Group	722 (47.0%)
Active Group	694 (53.0%)

Sample characteristics stratified by cognitive performance levels and univariate analysis results are presented in Supplemental Table 1. Several variables showed consistent significant differences between low and normal cognitive performance groups in all four cognitive tests. These included age, education level, ratio of family income to poverty, history of tinnitus, history of stroke and physical activity. Comparative analyses revealed significant distributional differences in: gender and history of heart disease in CERAD-T, CERAD-DR and DSST; depression symptoms in CERAD-T, AFT and DSST; high cholesterol in CERAD-T, CERAD-DR and AFT; history of hypertension and diabetes mellitus in AFT and DSST. Additional analyses showed significant ethnic disparities (Mexican American predominance) in CERAD-DR performance and marital status variations in DSST outcomes between cognitively impaired and unimpaired groups. Univariate analysis comparing participants with versus without self-reported sensory impairments further indicated significant global cognitive performance differences.

Following univariate analysis, all variables were incorporated into multivariate logistic regression models, with five adjustment models for each sensory impairment-cognition assessment pair. In analyses examining self-reported HL (Table 2), individuals with auditory impairment demonstrated consistently elevated odds ratios for low performance in all cognitive tests (CERAD-T, CERAD-DR, AFT, DSST, and global cognitive score) across all models. Similarly, participants reporting OD (Table 3) showed significantly higher odds of cognitive impairment across all four cognitive tests and global cognitive score in all adjusted models. This pattern persisted for GD (Table 4), where significant associations with cognitive decline were maintained across all adjustment models. Further cumulative analyses revealed progressively worse cognitive test scores with increasing numbers of sensory impairments (0 to 3), showing statistically significant intergroup differences (Figure 1).

Figure 1.

Trends of the cognitive test score with increasing numbers of sensory impairments.

Table 2.

Analysis for the associations between self-reported HL and low cognitive performance by adjustment models.

Cognitive tests with low performance	Model 1			Model 2			Model 3			Model 4			Model 5
Cognitive tests with low performance	OR^a	95% CI^a	p	OR^a	95% CI^a	p	OR^a	95% CI^a	p	OR^a	95% CI^a	p	OR^a	95% CI^a	p
CERAD-T	1.42	1.12, 1.81	0.004	1.38	1.07, 1.77	0.012	1.34	1.04, 1.73	0.022	1.34	1.04, 1.73	0.024	1.32	1.02, 1.71	0.032
CERAD-DR	1.77	1.39, 2.26	<0.001	1.71	1.33, 2.20	<0.001	1.64	1.27, 2.11	<0.001	1.62	1.25, 2.10	<0.001	1.59	1.22, 2.07	<0.001
AFT	1.78	1.40, 2.28	<0.001	2.06	1.60, 2.67	<0.001	2.01	1.55, 2.61	<0.001	1.97	1.51, 2.57	<0.001	1.93	1.47, 2.54	<0.001
DSST	1.73	1.36, 2.20	<0.001	2.07	1.59, 2.69	<0.001	2.03	1.54, 2.70	<0.001	2.04	1.53, 2.73	<0.001	1.87	1.39, 2.51	<0.001
Overall Cognition	1.46	1.13, 1.88	0.004	1.70	1.29, 2.24	<0.001	1.64	1.21, 2.21	0.001	1.64	1.21, 2.23	0.001	1.55	1.13, 2.12	0.007

OR: Odds Ratio, CI: Confidence interval.

Model 1: adjusted for age.

Model 2: adjusted for Model 1 plus gender, and race.

Model 3: adjusted for Model 2 plus education, marital status, and income to poverty ratio.

Model 4: adjusted for Model 3 plus impacted cerumen, ear canal stenosis, persistent cold/flu last 1 year, persistent dry mouth in past 1 year, nasal congestion in past 1 year and/or ≥2 sinusitis, tonsils removed, wisdom teeth removed, head/face/skull trauma, smoking history, history of drug use, and heavy drinker.

Model 5: adjusted for Model 4 plus depression symptoms, history of heart disease, history of stroke, history of hypertension, history of high cholesterol, history of diabetes mellitus and physical activity group.

Table 3.

Analysis for the associations between self-reported OD and low cognitive performance by adjustment models.

Cognitive tests with low performance	Model 1			Model 2			Model 3			Model 4			Model 5
Cognitive tests with low performance	OR^a	95% CI^a	p	OR^a	95% CI^a	p	OR^a	95% CI^a	p	OR^a	95% CI^a	p	OR^a	95% CI^a	p
CERAD-T	1.80	1.38, 2.35	<0.001	1.82	1.38, 2.40	<0.001	1.70	1.29, 2.25	<0.001	1.69	1.27, 2.24	<0.001	1.65	1.24, 2.20	<0.001
CERAD-DR	1.99	1.51, 2.61	<0.001	2.00	1.51, 2.65	<0.001	1.85	1.39, 2.46	<0.001	1.83	1.37, 2.44	<0.001	1.82	1.35, 2.44	<0.001
AFT	1.75	1.33, 2.29	<0.001	1.80	1.36, 2.37	<0.001	1.63	1.22, 2.17	<0.001	1.64	1.22, 2.18	<0.001	1.60	1.19, 2.16	0.002
DSST	2.13	1.63, 2.77	<0.001	2.34	1.76, 3.12	<0.001	2.08	1.53, 2.83	<0.001	2.14	1.57, 2.92	<0.001	1.96	1.42, 2.69	<0.001
Overall Cognition	1.58	1.19, 2.08	0.001	1.65	1.22, 2.22	0.001	1.46	1.07, 1.99	0.016	1.45	1.06, 1.98	0.018	1.40	1.02, 1.92	0.039

OR: Odds Ratio, CI: Confidence interval.

Model 1: adjusted for age.

Model 2: adjusted for Model 1 plus gender, and race.

Model 3: adjusted for Model 2 plus education, marital status, and income to poverty ratio.

Table 4.

Analysis for the associations between self-reported GD and low cognitive performance by adjustment models.

Cognitive tests with low performance	Model 1			Model 2			Model 3			Model 4			Model 5
Cognitive tests with low performance	OR^a	95% CI^a	p	OR^a	95% CI^a	p	OR^a	95% CI^a	p	OR^a	95% CI^a	p	OR^a	95% CI^a	p
CERAD-T	1.87	1.37, 2.55	<0.001	1.99	1.44, 2.75	<0.001	1.92	1.39, 2.66	<0.001	1.92	1.38, 2.66	<0.001	1.83	1.31, 2.55	<0.001
CERAD-DR	2.26	1.65, 3.11	<0.001	2.42	1.74, 3.36	<0.001	2.31	1.66, 3.23	<0.001	2.39	1.70, 3.37	<0.001	2.32	1.64, 3.30	<0.001
AFT	1.98	1.44, 2.70	<0.001	1.98	1.44, 2.71	<0.001	1.89	1.36, 2.61	<0.001	1.91	1.37, 2.67	<0.001	1.72	1.22, 2.43	0.002
DSST	1.73	1.27, 2.36	<0.001	1.86	1.33, 2.58	<0.001	1.74	1.22, 2.47	0.002	1.76	1.22, 2.53	0.002	1.56	1.07, 2.25	0.019
Overall Cognition	1.87	1.35, 2.56	<0.001	1.99	1.41, 2.80	<0.001	1.90	1.31, 2.74	<0.001	1.93	1.32, 2.82	<0.001	1.63	1.10, 2.42	0.015

OR: Odds Ratio, CI: Confidence interval.

Model 1: adjusted for age.

Model 2: adjusted for Model 1 plus gender, and race.

Model 3: adjusted for Model 2 plus education, marital status, and income to poverty ratio.

Discussion

This cross-sectional study analyzed NHANES 2011–2012 data from 1416 U.S. adults aged ≥60 years to investigate associations between self-reported HL, OD, GD, and performance on cognitive assessments. Multivariable-adjusted models demonstrated statistically significant associations between all three sensory impairments and poorer performance on each cognitive test. Subsequent analyses further confirmed consistent associations between sensory impairments and overall cognitive dysfunction.

Although hearing loss can start at any age, it typically comes to medical attention in the sixth decade of life and progresses slowly and symmetrically over decades. Affected individuals commonly report speech discrimination difficulties in noisy settings, persistent tinnitus, and sometimes a paradoxical hypersensitivity to loud sounds.²⁵ Longitudinal studies have demonstrated accelerated cognitive decline on the Modified Mini-Mental State Examination and DSST among hearing-impaired individuals over 6-year follow-up periods.²⁶ Our findings extend these observations, revealing significantly poorer performance across four cognitive domains in hearing-impaired adults >60 years, including assessments with minimal auditory demands. Mechanistically, hearing loss may accelerate cognitive deterioration through dual pathways: (1) by impairing social functioning and communication, and (2) by directly increasing the cognitive load on working memory, particularly during demanding tasks that exceed residual processing capacity.^27–29

Olfactory and gustatory dysfunction usually represents a common complaint among those afflicted with neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease, and more frequently occurs in the early stages of these pathologies.^30–32 Our findings corroborate established associations between OD and cognitive impairment,^33–35 with these relationships remaining statistically significant following adjustment for tobacco use, alcohol consumption, nasal/sinus pathologies, craniofacial trauma, cardio/cerebrovascular diseases, diabetes mellitus, psychiatric conditions, and physical activity levels. This robust association underscores the prognostic value of olfactory evaluation in detecting preclinical neurodegenerative processes. Existing literature has demonstrated taste abnormalities in populations with cognitive decline, mainly through Lang et al.'s study of GD in dementia patients and Steinbach et al.'s identification of taste discrimination-cognition correlations.^8,36 Our analysis provided further evidence, showing that subjective GD significantly associated with declined cognition across all cognitive domains after comprehensive covariate adjustment. Notably, these results suggest cognitive decline impacts broader chemosensory systems beyond olfaction, warranting expanded investigation into gustatory-cognitive interactions.

Our analysis revealed progressively worse cognitive performance in participants with multiple versus single sensory impairments, suggesting synergistic acceleration of cognitive deterioration through compounded sensory deficits. The neurocognitive consequences of multisensory impairment have gained substantial research interest, with evidence indicating that concurrent sensory deficits may exacerbate cognitive decline by overwhelming neural compensatory mechanisms.³⁷ For example, research involving institutionalized elders has demonstrated that dual sensory impairment (vision and hearing) is associated with accelerated cognitive decline, likely mediated by synergistic effects of social isolation and sensory deprivation on cognitive reserve depletion.³⁸ However, the neurocognitive interactions and mechanisms between HL combined with chemosensory dysfunctions (OD or GD) remain insufficiently elucidated. Since odor discrimination and identification are highly complex cognitive tasks that require comparison with information stored in memory and verbal labeling, whereas a detection threshold is less dependent of cognitive performance.^39,40 This methodological distinction necessitates cautious interpretation, as our data of sensory assessments may not fully capture the complex neurocognitive processes underlying multisensory impairment-related cognitive decline.

This study has several limitations. Firstly, the cross-sectional design precludes causal inferences between sensory impairments and cognitive outcomes, as age-related neurobiological processes may concurrently affect both sensory and cognitive functions. While we adjusted for established confounders, residual confounding from unmeasured variables remains possible. Secondly, objective sensory measures were unavailable due to incomplete data collection in the NHANES 2011–2012 cycle. Our analysis was restricted to NHANES-administered questionnaires and assessments, though well validated, which may lack universal standardization for diagnosing HL, OD, GD, or cognitive impairment. Future research should prioritize large-sample longitudinal studies incorporating multimodal objective sensory and cognitive assessments to elucidate temporal relationships and mechanistic pathways.

Conclusions

Self-reported hearing, olfactory, and gustatory dysfunction are significantly associated with impaired cognitive performance in older adults. Multiple sensory impairments may lead to progressively worse cognitive performance. These findings highlight the imperative for prospective studies that employ multimodal sensory and neurocognitive assessments to establish causality and elucidate the underlying mechanisms.

Supplemental Material

sj-docx-1-alr-10.1177_25424823251392551 - Supplemental material for Association between self-reported sensory impairments and low cognitive performance in older adults: A cross-sectional study based on National Health and Nutrition Examination Survey (NHANES)

Supplemental material, sj-docx-1-alr-10.1177_25424823251392551 for Association between self-reported sensory impairments and low cognitive performance in older adults: A cross-sectional study based on National Health and Nutrition Examination Survey (NHANES) by Lu He, Yuansheng Rao, Jianhong Wang and Fan Yang in Journal of Alzheimer's Disease Reports

Footnotes

Acknowledgements

The authors have no acknowledgments to report.

ORCID iD

Fan Yang

Ethical considerations

The NHANES cycles were approved by the CDC's National Center for Health Statistics (NCHS) Research Ethics Review Board (ERB). As this study utilizes publicly available, anonymized NHANES data, it does not require additional ethical review by the Ethics Committee of the authors’ institute.

Consent to participate

All participants provided written informed consent.

Consent for publication

Not applicable

Author contributions

Please replace this text with the Manuscript Author Contributions sent in the Manuscript metadata/information from Sage Track.

Author contribution(s)

Lu He: Conceptualization; Data curation; Formal analysis; Investigation; Writing – original draft.

Yuansheng Rao: Data curation; Resources; Validation; Writing – review & editing.

Jianhong Wang: Data curation; Investigation; Writing – review & editing.

Fan Yang: Conceptualization; Formal analysis; Methodology; Project administration; Supervision; Writing – review & editing.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Data availability statement

All data utilized in this study can be accessed from the NHANES website at .

Supplemental material

Supplemental material for this article is available online.

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