Gait Speed and Sleep Duration Is Associated with Increased Risk of MCI in Older Community-Dwelling Adults

Association of Sleep Disturbances With Prevalent and Incident Motoric Cognitive Risk Syndrome in Community-Residing Older Adults

BACKGROUND AND OBJECTIVES

There is growing evidence that sleep disturbances are associated with cognitive impairment risk, but their association with the incidence of motoric cognitive risk syndrome (MCR)-a predementia syndrome characterized by slow gait speed and cognitive complaints-is unknown. We aimed to examine the association of sleep disturbances, overall and specific subtypes, with (1) incident and (2) prevalent MCR in older adults.

METHODS

Community-residing adults aged 65 years and older without dementia were recruited from population lists and included in Central Control of Mobility and Aging, a prospective cohort study, in Albert Einstein College of Medicine, Bronx, NY. We included participants with available data for MCR and Pittsburgh Sleep Quality Index (PSQI). MCR was defined as cognitive complaints reported on standardized questionnaires and slow gait speed as recorded on an electronic treadmill and was adjudicated at baseline and annual follow-up visits. Participants were divided into "good" sleepers (≤5) and "poor" sleepers (>5) based on an established PSQI cut score. Among participants without MCR at baseline, Cox proportional hazard models adjusted for (1) age, sex, and education and (2) further for comorbidity index, Geriatric Depression Scale score, and global cognitive score were used to examine the association of baseline sleep disturbances with MCR incidence. Association between poor sleep quality and prevalent MCR at baseline in the overall population was explored using multivariate logistic regression analysis.

RESULTS

445 participants were included (56.9% women, mean age: 75.9 years [75.3; 76.5]). In MCR-free participants at baseline (n = 403), 36 developed incident MCR over a mean follow-up of 2.9 years. Poor sleepers had a higher risk of incident MCR (HR = 2.7 [1.2; 5.2]) compared with good sleepers, but this association was not significant after adjustment for depressive symptoms (adjusted hazard ratio [aHR] = 1.6 [0.7-3.4]). Among the 7 PSQI components, only sleep-related daytime dysfunction (excessive sleepiness and lower enthusiasm) showed a significant risk of MCR in fully adjusted models (aHR = 3.3 [1.5-7.4]). Prevalent MCR was not associated with poor sleep quality (OR [95% CI] = 1.1 [0.5-2.3]).

DISCUSSION

Overall poor sleep quality was associated with incident MCR, but not with prevalent MCR. Specifically, older adults with sleep-related daytime dysfunction are at increased risk of developing MCR. Further studies are needed to validate mechanisms of this relationship.

Characteristics of cadence during continuous walking in daily life

Despite the acknowledged relationship between the usual (preferred) walking speed (UWS) and health, there is currently no practical method available to reliably and accurately detect slight changes in UWS. This study aimed to explore whether either of the following two phenomena occurs during continuous daily walking in various periods: (a) Similarity between the most frequent cadences in the two periods. (b) The occurrence of the most frequent cadence in at least one of the two periods during the other period, with a frequency close to that of the most frequent cadence. In August 2021, invitations to participate in the study were extended via email to participants that took part in the Japan COVID-19 and Society Internet Surveys (JACSIS). A mobile phone application that collected step data during continuous walking was provided to the participants, and data were collected from December 1, 2021, to January 31, 2022. While 1022 participants installed the phone application, only 505 had measurement data for ten days or more in each of the two months of the study duration. The cadence during continuous walking was automatically measured daily from 05:00 to 21:00. Most participants exhibited at least one of the phenomena mentioned above, confirming a common, notably frequent, invariant cadence over time. Overall, this method allows for the identification of minor reductions and lower bounds of decline in UWS. This study illustrates the potential for tracking a decreasing trend in UWS. Early detection of a downward trend permits individuals to take timely remedial action, as recovery is relatively easy, and the confirmation of even a slight recovery bolsters recovery motivation.

Associations between the Timing and Nutritional Characteristics of Bedtime Meals and Sleep Quality for Nurses after a Rotating Night Shift: A Cross-Sectional Analysis

The purpose of this study was to investigate the associations of the timing and nutritional characteristics of bedtime meals with sleep quality in nurses after rotating night shifts. In total, 128 nurses from a university hospital in South Korea participated in this cross-sectional study. Data were collected on the first night of two or three consecutive routine night shifts. Participants recorded all food eaten before going to bed after work. An accelerometer was used to objectively measure sleep quality, and subjective sleep quality was assessed by self-report using the Korean version of the Verran and Snyder-Halpern Sleep Scale. The associations of timing and nutritional characteristics of bedtime meals with sleep quality after night shifts were analyzed using multivariate linear regression. A short time interval between meals and sleep was associated with longer objectively measured total sleep time (β = -0.37, p = 0.002), and the proportion of protein in meals was associated with better objectively measured sleep efficiency (β = 0.31, p = 0.007). The shorter the time interval, the better the subjective sleep quality (β = -0.23, p = 0.048), and high-calorie meals were positively associated with subjective sleep quality (β = 0.23, p = 0.043). Based on our findings, we encourage nurses to have protein-rich meals after night shifts and reduce the delay between meals and sleep. Although high-calorie meals were shown to have a positive effect on subjective sleep quality, it is necessary to confirm this effect through additional research.

The association between physical performance and subjective wellbeing in Chinese older adults: A cross-sectional study

Purpose

This study aimed to investigate the association between physical performance and subjective wellbeing among Chinese older adults.

Methods

Data on the Chinese population were gathered from the Study on Global Aging and Adult Health Survey (SAGE). This survey used a stratified multistage cluster sample design based on geographical location and economic status. Chinese older adults aged 65 years old or above from eight provinces (Guangdong, Hubei, Jilin, Shaanxi, Shandong, Shanghai, Yunnan, and Zhejiang) were included in this cross-sectional study. Physical performance was measured using relative handgrip strength and normal gait speed. Subjective wellbeing was measured using quality-of-life (QOL), happiness, and mood through interviews with participants. Logistic regressions were used to examine the associations between physical performance and each of the three wellbeing variables (QOL, happiness, and mood).

Results

Data of 5,421 Chinese older adults (mean age: 72.93 ± 5.89 years old, 47.1% men) were analyzed. In this sample, individuals with a higher level of relative handgrip strength (rHGS) had better mood compared to those with a lower level of rHGS (p < 0.05), and persons with lower gait speed had poorer QOL, happiness, and mood compared to those with faster gait speed (p < 0.05).

Conclusion

Our findings suggest that a higher level of relative handgrip strength predicted better mood and lower gait speed predicted poor QOL, happiness, and mood in Chinese older adults.