Sex-Specific Interactions Between Hearing and Memory in Older Adults With Mild Cognitive Impairment: Findings From the COMPASS-ND Study.

OBJECTIVES: Hearing loss (HL) in older adults is associated with a decline in performance on cognitive tasks and the risk of developing dementia. However, very few studies have investigated sex-related effects on these associations. A previous study of cognitively healthy older adults showed an association between HL and lower cognitive performance in females only. In the present study, we examined the effects of sex and hearing on cognition in individuals with mild cognitive impairment (MCI). We predicted that females with HL would be more likely to show poorer performance on the cognitive measures compared to females with normal hearing (NH), while cognitive performance in males would not depend on hearing. We further predicted that these auditory-cognitive associations would not depend on test modality, and would thus be observed in females for both auditory and visual tests. DESIGN: Participants were 101 older adults with amnestic MCI (M = 71 years, 45% females) in the Canadian Consortium on Neurodegeneration in Aging (CCNA) COMPASS-ND study. Performance on the Montreal Cognitive Assessment (MoCA), Rey Auditory Verbal Learning (RAVLT), and Brief Visuospatial Memory Test-Revised (BVMT-R) was analyzed to investigate sex-related differences and/or hearing-related differences. Participants were categorized as having NH or HL using two different measures: pure-tone hearing screening results (normal based on a pure-tone threshold < 25 dB HL at 2000 Hz in the worse ear) and speech-in-noise speech reception thresholds (SRTs; normal < -10 dB SNR on the Canadian Digit Triplet Test [CDTT]). RESULTS: Males and female groups did not differ in age, years of education, or other relevant covariates. Yet, females with better hearing on either pure-tone or speech-in-noise measures outperformed their worse hearing counterparts on the MoCA total score. Additionally, females with better hearing were more likely to recall several words on the MoCA delayed recall trial relative to those with worse hearing. Females with NH showed significant correlations between CDTT SRTs and both MoCA and RAVLT scores, while no correlations were observed in males. In contrast, males but not females showed an effect of hearing group on BVMT-R test status. CONCLUSIONS: There were sex-specific differences in auditory-cognitive associations in individuals with MCI. These associations were mostly observed in females and on auditory tests. Potential mechanisms and implications are discussed.

Sex-Related Differences in the Associations Between Montreal Cognitive Assessment Scores and Pure-Tone Measures of Hearing.

PURPOSE: Hearing loss (HL) is associated with cognitive performance in older adults, including performance on the Montreal Cognitive Assessment (MoCA), a brief cognitive screening test. Yet, despite well-established sex-related differences in both hearing and cognition, very few studies have tested whether there are sex-related differences in auditory-cognitive associations. METHOD: In the current cross-sectional retrospective analysis, we examined sex-related differences in hearing and cognition in 193 healthy older adults (M = 69 years, 60% women). Hearing was measured using audiometry (pure-tone average [PTA] of thresholds at 500, 1000, 2000, and 4000 Hz in the worse ear). Cognition was assessed using the MoCA. Additionally, we calculated MoCA scores with hearing-dependent subtests excluded from scoring (MoCA-Modified). RESULTS: Men and women did not differ in age, education, or history of depression. Women had better hearing than men. Women with normal hearing were more likely to pass the MoCA compared with their counterparts with HL. In contrast, the likelihood of passing the MoCA did not depend on hearing status in men. Linear regression analysis showed an interaction between sex and PTA in the worse ear. PTAs were significantly correlated with both MoCA and MoCA-Modified scores in women, whereas this was not observed in the men. CONCLUSIONS: This study is one of the first to demonstrate significant sex-related differences in auditory-cognitive associations even when hearing-related cognitive test items are omitted. Potential mechanisms underlying these female-specific effects are discussed. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.19233297.

Visual Performance and Cortical Atrophy in Vision-Related Brain Regions Differ Between Older Adults with (or at Risk for) Alzheimer's Disease.

BACKGROUND: Visual impairment is associated with deficits in cognitive function and risk for cognitive decline and Alzheimer's disease (AD). OBJECTIVE: The purpose of this study was to characterize the degree of visual impairment and explore the association thereof with cortical atrophy in brain regions associated with visual processing in individuals with (or at risk for) AD. METHODS: Using the Comprehensive Assessment of Neurodegeneration and Dementia (COMPASS-ND) dataset, we analyzed vision and brain imaging data from three diagnostic groups: individuals with subjective cognitive decline (SCD; N = 35), mild cognitive impairment (MCI; N = 74), and mild AD (N = 30). We used ANCOVAs to determine whether performance on reading acuity and contrast sensitivity tests differed across diagnostic groups. Hierarchical regression analyses were applied to determine whether visual performance predicted gray matter volume for vision-related regions of interest above and beyond group membership. RESULTS: The AD group performed significantly worse on reading acuity (F(2,138) = 4.12, p < 0.01, ω2 = 0.04) compared to the SCD group and on contrast sensitivity (F(2,138) = 7.6, p < 0.01, ω2 = 0.09) compared to the SCD and MCI groups, which did not differ from each other. Visual performance was associated with volume in some vision-related structures beyond clinical diagnosis. CONCLUSION: Our findings demonstrate poor visual performance in AD and that both group membership and visual performance are predictors of cortical pathology, consistent with the idea that atrophy in visual areas and pathways contributes to the functional vision deficits observed in AD.

The Montreal Cognitive Assessment After Omission of Hearing-Dependent Subtests: Psychometrics and Clinical Recommendations.

OBJECTIVES: Hearing loss (HL) is the third most common chronic health condition in older adults, yet it is often undiagnosed and/or untreated. Given the association between HL and cognitive impairment, it is expected that many people undergoing cognitive screening may have HL. The Montreal Cognitive Assessment (MoCA) is a brief screening test that assesses a wide range of cognitive functions sensitive to Alzheimer's disease (AD) and mild cognitive impairment (MCI). Although MoCA items were carefully designed to be sensitive to deficits in MCI, they were not designed to take sensory declines into account. In the current investigation, we examined the MoCA's psychometric properties following omission of subtests primarily dependent on hearing status (memory, digit span, attention to letters, and sentence repetition). DESIGN: Cross-sectional analytic design (retrospective analysis). SETTING: We used the original MoCA validation study data.4 PARTICIPANTS: Groups consisted of healthy controls (N = 90), subjects with MCI (N = 94), and subjects with mild AD (N = 93). MEASUREMENTS: We assessed sensitivity and specificity using absolute and proportional cutoff score adjustments. We developed receiver operating characteristics curves to determine the best cutoff values for both MCI and AD patients using different combinations of auditory subtest omissions. RESULTS: Compared with the original MoCA (MCI sensitivity = 90%; specificity = 87%), MCI sensitivity was substantially reduced (absolute scoring = 43%; proportional scoring = 56%) when all auditory subtests were omitted, with the biggest contribution to the reduction coming from the delayed recall subtest. Excluding three subtests and maintaining the delayed recall had no effect on MCI sensitivity but reduced specificity (sensitivity = 94%, specificity: 71% using proportional scoring). AD sensitivity, in contrast, was not strongly influenced by our manipulation and remained relatively high through all three subtest omission combinations. CONCLUSION: The current study highlights the contribution of hearing-dependent subtests on the sensitivity and specificity of the MoCA. Clinical recommendations related to these findings are discussed. J Am Geriatr Soc 67:1689-1694, 2019.

Relations between plasma oxytocin and cortisol: The stress buffering role of social support.

Stress responses in humans can be attenuated by exogenous oxytocin administration, and these stress-buffering properties may be moderated by social factors. Yet, the influence of acute stressors on circulating endogenous oxytocin levels have been inconsistent, and limited information is available concerning the influence of social support in moderating this relationship. In the current investigation, undergraduate women (N = 67) were assessed in the Trier Social Stress Test (TSST) with either social support available from a close female friend or no social support being available. An additional set of women served as controls. The TSST elicited marked elevations of state anxiety and negative emotions, which were largely attenuated among women who received social support. Furthermore, baseline oxytocin levels were inversely related to women's general feelings of distrust, as well as basal plasma cortisol levels. Despite these associations, oxytocin levels were unaffected by the TSST, and this was the case irrespective of oral contraceptive use or estrogen levels. In contrast, plasma cortisol elevations were elicited by the psychosocial stressor, but only in women using oral contraceptives, an effect that was prevented when social support was available. Taken together, these data provisionally suggest that changes in plasma oxytocin might not accompany the stress attenuating effects of social support on cortisol levels. Moreover, as plasma oxytocin might not reliably reflect brain oxytocin levels, the linkage between oxytocin and prosocial behaviors remains tenuous.

Synergistic and antagonistic actions of acute or chronic social stressors and an endotoxin challenge vary over time following the challenge.

Acute stressor exposure and immunogenic challenges can synergistically increase behavioral, endocrine and neuroinflammatory responses, but much less is known about how chronic stressors influence the actions of immune challenges. In the present investigation we assessed the influence of bacterial endotoxin, lipopolysaccharide (LPS), administered on an acute chronic stressors backdrop, on sickness behavior, changes of circulating corticosterone and cytokine levels, and cytokine mRNA expression in the prefrontal cortex (PFC) and hippocampus. In this regard, it was of particular interest to determine whether the stressors would alter the temporal biological effects (onset and normalization) of LPS. There was a leftward shift in the temporal curve, in that sickness behavior, corticosterone and plasma IL-6 elevations among stressed mice appeared sooner after LPS treatment, but 3h after treatment corticosterone and IL-6 were lower than in nonstressed mice. In contrast, the stressor, especially when applied chronically, diminished the effects of LPS on TNF-α over the course of measurement, whereas effects on IL-10 were enhanced. In contrast to these peripheral effects, central cytokine mRNA expression, especially IL-1ß and TNF-α, were diminished 1.5h following stressor and LPS administration, but were then synergistically enhanced at 3h compared to non-stressed controls. Although acute and chronic stressors provoked similar behavioral and neuroendocrine responses when combined with LPS, the effects of chronic stressors and LPS on brain cytokines were generally diminished, particularly in the PFC. The implications of the temporal changes related to stressors and immune activation are discussed, and several possible mechanisms for these effects are suggested.