Preserving Cognition, Preventing Dementia

[Cognitive impairment in hearing impaired patients compared to normal hearing patients]

Background

Hearing loss affects 360 million people worldwide and it is linked to cognitive impairment, which is the main precursor of dementia. Hearing loss is the major modifiable risk factor for cognitive impairment. This study examines the relationship between severe/profound hearing loss and cognitive impairment in people aged 50 to 65 years.

Objective

To determine whether severe/profound hearing loss accelerates the development of cognitive impairment in patients with this condition compared to those with normal hearing or mild hearing loss. Material and methods: Analytical cross-sectional study conducted in 254 patients. Degrees of hearing loss were assessed by tonal audiometry using the World Health Organization (WHO) criteria, and the degree of cognitive impairment with the Montreal Cognitive Assessment (MoCA) test. The variables analyzed included age, sex, schooling and socioeconomic level.

Results

82.8% of patients with severe/profound hearing loss had cognitive impairment, compared to 17.2% of those with normal hearing (p < 0.001), demonstrating a highly significant association between hearing loss and cognitive impairment.

Conclusions

Patients with severe/profound hearing loss have greater cognitive impairment than those with normal hearing. Early diagnosis and treatment, such as the use of hearing aids, is key to prevent cognitive impairment and improve quality of life.

Study protocol for a longitudinal observational study of disparities in sleep and cognition in older adults: the DISCO study

INTRODUCTION

Cognitive dysfunction, a leading cause of mortality and morbidity in the USA and globally, has been shown to disproportionately affect the socioeconomically disadvantaged and those who identify as black or Hispanic/Latinx. Poor sleep is strongly associated with the development of vascular and metabolic diseases, which correlate with cognitive dysfunction. Therefore, sleep may contribute to observed disparities in cognitive disorders. The Epidemiologic Study of Disparities in Sleep and Cognition in Older Adults (DISCO) is a longitudinal, observational cohort study that focuses on gathering data to better understand racial/ethnic sleep disparities and illuminate the relationship among sleep, race and ethnicity and changes in cognitive function. This investigation may help inform targeted interventions to minimise disparities in cognitive health among ageing adults.

METHODS AND ANALYSIS

The DISCO study will examine up to 495 individuals aged 55 and older at two time points over 24 months. An equal number of black, white and Hispanic/Latinx individuals will be recruited using methods aimed for adults traditionally under-represented in research. Study procedures at each time point will include cognitive tests, gait speed measurement, wrist actigraphy, a type 2 home polysomnography and a clinical examination. Participants will also complete self-identified assessments and questionnaires on cognitive ability, sleep, medication use, quality of life, sociodemographic characteristics, diet, substance use, and psychological and social health.

ETHICS AND DISSEMINATION

This study was approved by the Northwestern University Feinberg School of Medicine Institutional Review Board. Deidentified datasets will be shared via the BioLINCC repository following the completion of the project. Biospecimen samples from the study that are not being analysed can be made available to qualified investigators on review and approval by study investigators. Requests that do not lead to participant burden or that conflict with the primary aims of the study will be reviewed by the study investigators.

Impact of shift work on dementia: a systematic review and dose-response meta-analysis

OBJECTIVES

Although shift work has been reported as having a link to dementia, evidence remains inconsistent, and a comprehensive dose-response meta-analysis of the association is still lacking. We therefore conducted this meta-analysis to explore the association between shift work and the risk of dementia.

STUDY DESIGN

Systematic review and dose-response meta-analysis.

METHODS

PubMed, Embase, and Web of Science databases were systematically searched. Fixed or random-effects models were used to estimate the summary relative risks (RRs) and 95% confidence intervals (95% CIs). Generalized least squares regression was used to estimate dose-response associations, and restricted cubic splines were used to examine possible linear or non-linear associations.

RESULTS

Five articles (10 studies) with 72,999 participants and 23,067 cases were eventually included in the meta-analysis. The summary RRs and 95% CIs of dementia risk with shift work and night shift work versus daytime work were 1.13 (95% CI: 1.05-1.21, I2 = 46.70%) and 1.13 (95% CI: 1.03-1.24, I2 = 9.20%), respectively. The risk of dementia increased by 1% (RR = 1.01, 95% CI: 1.01-1.02, I2 = 41.3%) with each 1-year increase in the duration of shift work. We found a non-linear dose-response association between the duration of shift work and the risk of dementia (Pnon-linearity = 0.006). Though the shape of the curve was steeper with the duration of shift work <7 years, the increase was more gradual after 7 years.

CONCLUSION

Our findings suggest that shift work may be a risk factor for future dementia and that controlling the length of shift work is a feasible measure that may contribute to prevent dementia.

Associations between trajectories of cardiovascular risk factor change and cognitive impairment in Chinese elderly: A nationwide cohort study

Objectives

This study aimed to investigate the relationship between long-term trajectories of changes in cardiovascular risk factors (CVRFs) and the risk of cognitive impairment among Chinese adults over 60 years old.

Methods

Data were obtained from the Chinese Longitudinal Healthy Longevity Survey 2005-2018. Cognitive function was evaluated longitudinally through the Chinese version of the Mini-Mental State Examination (C-MMSE), and cognitive impairment (C-MMSE ≤23) was used as the main outcome variable. The cardiovascular risk factors, including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), and body mass index (BMI), were continuously measured in the follow-up duration. The patterns of trajectories of changes in CVRFs were derived from the latent growth mixture model (LGMM). The Cox regression model was used to evaluate the cognitive impairment hazard ratio (HR) across different CVRF trajectories.

Results

A total of 5,164 participants aged ≥60 years with normal cognitive function at baseline were included in the study. After a median follow-up of 8 years, 2,071 participants (40.1%) developed cognitive impairment (C-MMSE ≤ 23). The four-class trajectories of SBP and BMI were obtained by means of LGMM, and the trajectories of DBP, MAP, and PP were grouped into a three-class subgroup. In the final adjusted Cox model, the lowered SBP [adjusted HR (aHR): 1.59; 95% CI: 1.17-2.16], lowered PP (aHR: 2.64; 95% CI: 1.66-4.19), and progressively obese (aHR: 1.28; 95% CI: 1.02-1.62) and stable slim (aHR: 1.13; 95% CI: 1.02-1.25) were associated with the higher risk of cognitive impairment. Low stable DBP (aHR: 0.80; 95% CI: 0.66-0.96) and elevated PP (aHR: 0.76; 95% CI: 0.63-0.92) decreased the risk for cognitive impairment among participants.

Conclusion

Lowered SBP, lowered PP, progressive obesity, and stable slim increased the risk for cognitive impairment in the Chinese elderly. Low stable DBP and elevated PP were protective against cognitive impairment, but more DBP lowering and ≥25 mmHg growth in PP contributed to a higher risk of cognitive impairment. The findings have important implications for preventing cognitive impairment in elder adults based on the long-term trajectories of changes in CVRFs.

Association of bilateral oophorectomy and menopause hormone therapy with mild cognitive impairment: the REDLINC X study

BACKGROUND

Dementia is a major public health problem. Estrogen is a regulator of the central nervous system and its deficit could be involved in cognitive decline in older women.

OBJECTIVE

This study aimed to evaluate the association of bilateral oophorectomy, menopause hormone therapy (MHT) and other factors on mild cognitive impairment (MCI).

METHOD

The case-control study included 941 otherwise healthy postmenopausal women aged 60 years and over from six Latin American countries. Personal and family data were recorded and MCI was assessed using the Montreal Cognitive Assessment test (MoCA).

RESULTS

Average age, years of education and body mass index were 66.1 ± 5.8 years, 12.4 ± 5.0 years and 26.0 ± 4.3 kg/m², respectively. A total of 30.2% had undergone bilateral oophorectomy and 40.3% had used MHT. A total of 232 women (24.7%) had MCI. The prevalence of MCI was higher in women with intact ovaries and non-MHT users as compared to MHT users (29.3% vs. 11.7% [odds ratio (OR) 0.32; 95% confidence interval (CI) 0.20-0.51]). Among oophorectomized women, MCI prevalence was higher among non-MHT users as compared to MHT users (45.2% vs. 12.8% [OR 0.18; 95% CI 0.10-0.32]). Logistic regression analysis determined that the variables associated with MCI were age >65 years (OR 1.69; 95% CI 1.20-2.38), parity (having >2 children; OR 1.69; 95% CI 1.21-2.37), bilateral oophorectomy (OR 1.56; 95% CI 1.09-2.24), hypertension (OR 1.41; 95% CI 1.01-1.96), being sexually active (OR 0.56; 95% CI 0.40-0.79), education >12 years (OR 0.46; 95% CI 0.32-0.65) and MHT use (OR 0.31; 95% CI 0.21-0.46).

CONCLUSION

Age, parity, bilateral oophorectomy and hypertension are independent factors associated with MCI; contrary to this, higher educational level, maintaining sexual activity and using MHT are protective factors.

Brain training using cognitive apps can improve cognitive performance and processing speed in older adults

Managing age-related decrease of cognitive function is an important public health challenge, especially in the context of the global aging of the population. Over the last years several Cognitive Mobile Games (CMG) have been developed to train and challenge the brain. However, currently the level of evidence supporting the benefits of using CMG in real-life use is limited in older adults, especially at a late age. In this study we analyzed game scores and the processing speed obtained over the course of 100 sessions in 12,000 subjects aged 60 to over 80 years. Users who trained with the games improved regardless of age in terms of scores and processing speed throughout the 100 sessions, suggesting that old and very old adults can improve their cognitive performance using CMG in real-life use.