High-intensity physical activity is not associated with better cognition in the elder: evidence from the China Health and Retirement Longitudinal Study

Isotemporal Substitution of Sedentary Time With Physical Activity Among Middle-Aged and Older Latinos: Effects on Episodic Memory

PURPOSE

To examine the estimated effects of substituting 30 min of sedentary time with low-light physical activity (LLPA) and high-light physical activity (HLPA) on episodic memory, executive functioning, and working memory among middle-aged and older Latinos.

DESIGN

A cross-sectional study.

SETTING

Chicago and Chicagoland suburbs.

SUBJECTS

Middle-aged and older Latinos (n = 61).

MEASURES

Accelerometer-assessed physical activity. A cognitive battery was administered to assess episodic memory, executive function, and working memory.

ANALYSIS

Isotemporal substitution analyses were conducted, where unstandardized coefficients from linear regression models were used to examine the substitution effect of replacing sedentary time with LLPA and HLPA.

RESULTS

Substitution of sedentary time with LLPA was associated with better episodic memory (Immediate recall, B = .947, P = .008; Delayed recall, B = .857, P = .013). No other significant substitution effects were present.

CONCLUSION

Middle-aged and older Latinos who replace sedentary time with LLPA may have better episodic memory. Future studies may target light physical activity to address cognition disparities and can inform the development of physical activity interventions that are appealing and accessible for Latinos.

Joint association of TyG index and high sensitivity C-reactive protein with cardiovascular disease: a national cohort study

BACKGROUND

Both the triglyceride-glucose (TyG) index, as a surrogate marker of insulin resistance, and systemic inflammation are predictors of cardiovascular diseases; however, little is known about the coexposures and relative contributions of TyG index and inflammation to cardiovascular diseases. Using the nationally representative data from the China Health and Retirement Longitudinal Study (CHARLS), we conducted longitudinal analyses to evaluate the joint and mutual associations of the TyG index and high-sensitivity C-reactive protein (hsCRP) with cardiovascular events in middle-aged and older Chinese population.

METHODS

This study comprised 8 658 participants aged at least 45 years from the CHARLS 2011 who are free of cardiovascular diseases at baseline. The TyG index was calculated as Ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. Cardiovascular events were defined as the presence of physician-diagnosed heart disease and/or stroke followed until 2018.We performed adjusted Cox proportional hazards regression and mediation analyses.

RESULTS

The mean age of the participants was 58.6 ± 9.0 years, and 3988 (46.1%) were females. During a maximum follow-up of 7.0 years, 2606 (30.1%) people developed cardiovascular diseases, including 2012 (23.2%) cases of heart diseases and 848 (9.8%) cases of stroke. Compared with people with a lower TyG index (< 8.6 [median level]) and hsCRP < 1 mg/L, those concurrently with a higher TyG and hsCRP had the highest risk of overall cardiovascular disease (adjusted hazard ratio [aHR], 1.300; 95% CI 1.155-1.462), coronary heart disease (aHR, 1.294; 95% CI 1.130-1.481) and stroke (aHR, 1.333; 95% CI 1.093-1.628), which were predominant among those aged 70 years or below. High hsCRP significantly mediated 13.4% of the association between the TyG index and cardiovascular disease, while TyG simultaneously mediated 7.9% of the association between hsCRP and cardiovascular risk.

CONCLUSIONS

The findings highlight the coexposure effects and mutual mediation between the TyG index and hsCRP on cardiovascular diseases. Joint assessments of the TyG index and hsCRP should be underlined for the residual risk stratification and primary prevention of cardiovascular diseases, especially for middle-aged adults.

Intraindividual difference in estimated GFR by creatinine and cystatin C, cognitive trajectories and motoric cognitive risk syndrome

BACKGROUND

Intraindividual differences between estimated glomerular filtration rate (eGFR) based on cystatin C (eGFRcys) and creatinine (eGFRcr) can convey important clinical information regarding health status. However, the clinical implications of these differences (eGFRdiff) for risk of cognitive decline and motoric cognitive risk (MCR) syndrome remains unclear. We aimed to investigate the longitudinal associations of eGFRdiff with cognitive trajectories and incident MCR.

METHODS

Based on the China Health and Retirement Longitudinal Study, we identified two study subcohorts: one for cognitive trajectory follow-up (6423 participants, 2011-2018) and another for incident MCR follow-up (2477 participants, 2011-2015). The eGFRdiff was defined as eGFRcys - eGFRcr. Adjusted ordinal and binary logistic regression models were separately used to assess the associations of eGFRdiff with cognitive trajectories and incident MCR. We also performed discordance analyses for eGFRdiff versus eGFRcys, eGFRcr or eGFR based on both creatinine and cystatin C (eGFRcys-cr).

RESULTS

In the first subcohort, four distinct 7-year cognitive trajectories were identified. Each 1 standard deviation (SD) higher eGFRdiff (value for eGFRcys - eGFRcr) was associated with a lower risk of poorer cognitive trajectories {odds ratio 0.909 [95% confidence interval (CI) 0.877-0.942]}. In the second subcohort, 121 participants developed incident MCR after a 4-year follow-up. Each 1-SD higher eGFRdiff (value for eGFRcys - eGFRcr) was linked with a 25.3% (95% CI 16.6-33.2) decreased risk for MCR. The above associations persisted in individuals with normal kidney function. Additionally, the risk for cognitive decline and incident MCR was more strongly associated with eGFRcys than eGFRcr and eGFRcys-cr. For the discordance analyses, the 'discordantly high eGFRdiff/low eGFR' group but not the 'discordantly low eGFRdiff/high eGFR' exhibited a significantly lower risk of poorer cognitive trajectories and MCR compared with the concordant group.

CONCLUSIONS

A large negative difference between eGFRcys and eGFRcr (eGFRcys < eGFRcr) was associated with a higher risk of cognitive decline and incident MCR. The eGFRdiff could capture additional valuable risk information beyond eGFRcys, eGFRcr and eGFRcys-cr.

Serum cystatin C and stroke risk: a national cohort and Mendelian randomization study

Purpose

The debate over the causal and longitudinal association between cystatin C and stroke in older adults persists. Our aim was to assess the link between cystatin C levels, both measured and genetically predicted, and stroke risk.

Methods

This study employed a retrospective cohort design using samples of the China Health and Retirement Longitudinal Study (CHARLS), which is a nationally representative cohort recruiting individuals aged 45 years or above. A multivariate logistic model and the two-sample Mendelian randomization framework were used to investigate the longitudinal and genetically predicted effect of serum cystatin C on stroke.

Results

The study population had a mean age of 59.6 (SD ±9.5), with 2,996 (46.1%) women. After adjusting for confounding factors, compared to those in the first quartile of cystatin C, those in the last quartile had the greatest risk of stroke incidence [odds ratio (OR), 1.380; 95% confidence interval (CI), 1.046-1.825]. The Mendelian randomization analysis showed that a genetically predicted cystatin C level was positively associated with total stroke (OR by inverse variance-weighted method, 1.114; 95% CI, 1.041-1.192).

Conclusions

This national cohort study suggests that higher serum cystatin C is associated with an increased risk of total stroke, which is further supported by Mendelian randomization.

Visual memory and alcohol use in a middle-aged birth cohort

Light and moderate alcohol use has been reported to be associated with both impaired and enhanced cognition. The purpose of this study was to explore whether there was a linear relationship between visual memory and alcohol consumption in males and females in a large middle-aged birth cohort population in cross-sectional and longitudinal settings. Data were collected from 5585 participants completing 31-year (1997-1998) and 46-year (2012-2014) follow-ups including Paired Associate Learning (PAL) test at 46-years follow-up. The participants were originally from 12,231 study population of the Northern Finland Birth Cohort 1966 (NFBC1966). The PAL test was conducted to assess visual memory. Reported alcohol use was measured as total daily use of alcohol, beer, wine, and spirits converted into grams and as frequency and amount of use of beer, wine, and spirits. The total daily alcohol use was not associated with reduced visual memory. The frequency of use of beer and wine in males was associated with better visual memory in cross-sectional and longitudinal settings. Using six or more servings of spirits was associated with worse visual memory in males in cross-sectional and longitudinal settings. Using six or more servings of spirits was associated with worse visual memory in males in cross-sectional and longitudinal setting. The study suggested a lack of a linear association between drinking and visual memory in the middle-aged population.

The joint effects of sarcopenia and cardiometabolic risk factors on declined cognitive function: Evidence from a 7-year cohort study

BACKGROUND

Sarcopenia and cardiometabolic risk factors are very common in the middle-aged and older population. This study aimed to explore the joint effect of sarcopenia and cardiometabolic risk factors on cognitive performance and cognitive decline.

METHODS

The definition of sarcopenia status was referenced in the AWGS 2019 algorithm. Linear regression models were used to explore the association of sarcopenia status with cognitive performance at baseline. Mixed effect models and multinomial logistic regression models were used to evaluate the long-term effect of sarcopenia status. The additive interaction between the effects of sarcopenia and cardiometabolic risk factors on cognitive performance was also evaluated.

RESULTS

In the cross-sectional analysis, sarcopenia and possible sarcopenia were associated with worse cognitive performance. In the longitudinal analysis, the participant with sarcopenia had a 0.34 [95 % CI (-0.43, -0.24)] lower global cognition score, and those with possible sarcopenia had a 0.20 [95 % CI (-0.27, -0.14)] lower global cognition score, compared with participants with no-sarcopenia. Sarcopenia and possible sarcopenia were identified as significant risk factors for cognitive decline. Sarcopenia combined with hypertension, type 2 diabetes, dyslipidemia, or abdominal obesity was associated with worse cognitive function.

LIMITATIONS

The assessment of cognitive function was not diagnosed accurately.

CONCLUSIONS

Sarcopenia and possible sarcopenia had adverse effects on cognitive performance and cognitive decline, sarcopenia combined with cardiometabolic risk factors can significantly enhance these effects. Therefore, the prevention of sarcopenia in the older population is crucial.

Triglyceride-glucose index, renal function and cardiovascular disease: a national cohort study

BACKGROUND

The triglyceride-glucose (TyG) index is a predictor of cardiovascular diseases; however, to what extent the TyG index is associated with cardiovascular diseases through renal function is unclear. This study aimed to evaluate the complex association of the TyG index and renal function with cardiovascular diseases using a cohort design.

METHODS

This study included participants from the China Health and Retirement Longitudinal Study (CHARLS) free of cardiovascular diseases at baseline. We performed adjusted regression analyses and mediation analyses using Cox models. The TyG index was calculated as Ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. Renal function was defined by the estimated glomerular filtration rate (eGFR).

RESULTS

A total of 6 496 participants were included in this study. The mean age of the participants was 59.6 ± 9.5 years, and 2996 (46.1%) were females. During a maximum follow-up of 7.0 years, 1 996 (30.7%) people developed cardiovascular diseases, including 1 541 (23.7%) cases of heart diseases and 651 (10.0%) cases of stroke. Both the TyG index and eGFR level were significantly associated with cardiovascular diseases. Compared with people with a lower TyG index (median level) and eGFR ≥ 60 ml/minute/1.73 m2, those with a higher TyG index and decreased eGFR had the highest risk of cardiovascular diseases (HR, 1.870; 95% CI 1.131-3.069). Decreased eGFR significantly mediated 29.6% of the associations between the TyG index and cardiovascular diseases.

CONCLUSIONS

The combination of a higher TyG index and lower eGFR level was associated with the highest risk of cardiovascular diseases. Renal function could mediate the association between the TyG index and cardiovascular risk.

Gender differences in depressive symptoms among Chinese older adults based on fairlie decomposition analysis

This study aimed to investigate the factors influencing depressive symptoms among Chinese older adults based on gender differences. Data from the eighth wave of Chinese Longitudinal Health Longevity Survey were used. We analyzed the influencing factors of depressive symptoms reported by older adults using the chi-squared test and logistic model. Fairlie decomposition analysis was performed to quantify the contribution level of each influencing factor. We found that 11.71 % of older adults met the CES-D-10 criteria for depressive symptoms. Females (13.89 %) reported a significantly higher level of depressive symptoms than males (9.24 %). Age, residence, sleeping time, exercise, activities of daily living functional disability, instrumental activity of daily living functional disability, and living status influenced depressive symptoms in older adults. Higher education and lower body mass index were only significant in male, whereas middle annual income and exercising were significant only in female. The Fairlie decomposition model explained the reasons for 75.64 % of the gender differences in depressive symptoms, with instrumental activity of daily living functional disability (33.60 %), age (-17.79 %), and education level (17.41 %) being major factors affecting gender differences in depressive symptoms. This is the first nationwide study to examine gender differences in depressive symptoms among older adults. These results provide a basis for relevant Chinese government departments to formulate policies to prevent and control depressive symptoms.

Threshold effects of the relationship between physical exercise and cognitive function in the short-sleep elder population

Background

It has been demonstrated that elderly people's cognitive capacities can be improved with exercise, and short sleep is linked to cognitive decline. However, the impact of physical exercise on cognitive performance in seniors who do not get enough sleep is largely unknown. This makes it an intriguing subject to explore further.

Methods

This study consisted of elders (over 60 years old) who participated throughout the National Health and Nutrition Examination Survey's 2011-2014 cycle (NHANES). Weighted linear regression model and restricted cubic splines analysis were performed to evaluate the association between physical exercise and cognitive function. In the end, 1,615 samples were scrutinized and the total number of weighted respondents was 28,607,569.

Results

Results showed that in the Animal Fluency test and the Digit Symbol Substitution test, a positive association was found between physical exercise volume and scores in the fully adjusted model. A two-piecewise linear regression model was then applied to explore the threshold effect of exercise on cognitive performance. Before 960 and 800 MET-minutes/week, there were consistent positive relationship between exercise and scores of the Animal Fluency test [ß (95% CI): 0.233 (0.154, 0.312), p < 0.001] and Digit Symbol Substitution test [β (95% CI): 0.555 (0.332, 0.778), p < 0.001], respectively. However, there was a saturation effect where physical exercise volume reached the two inflection points.

Conclusion

According to our research, the benefit of exercise did not always expand with the exercise volume increment under the short-sleep condition, which challenged existing knowledge. The short-sleep elder group could maintain cognitive performance with no more than 800 MET-minutes/week of physical exercise. Verification of these findings requires further biological investigations.

Physical activity trajectories and their determinants in patients with chronic obstructive pulmonary disease: A cohort study

AIMS AND OBJECTIVES

The aim was to identify latent trajectories in physical activity (PA) and their determinants in adults with chronic obstructive pulmonary disease (COPD) based on the socio-ecological model.

BACKGROUND

PA has been linked to poor long-term outcomes in patients with COPD. However, few studies have explored their PA trajectories and their predictors.

DESIGN

Cohort study.

METHODS

We used data from a national cohort and included 215 participants. PA was quantified using a short PA questionnaire, and group-based trajectory modelling was used to explore the PA trajectories. Multinomial logistic regression was conducted to identify the predictors of PA trajectories. Generalised linear mixed models were used to elucidate the associations between predictors and PA during follow-up. A STROBE checklist was used to guide the reporting of this study.

RESULTS

Three PA trajectory patterns were identified among 215 COPD participants with an average age of 60.51 ± 8.87: stable inactive group (66.7%), sharp decline group (25.7%) and stable active group (7.5%). The logistic regression showed that age, sex, income, peak expiratory flow, upper limb capacity, depressive symptoms, the frequency of contact with children were PA predictors. Upper limb capacity weakness and depressive symptoms were found to be associated with a sharp decline in PA during follow-up.

CONCLUSIONS

This study revealed three PA trajectories among patients with COPD. In addition to strengthening the physical functions and mental health of patients, support from the family, community and society also play a crucial role in promoting PA of patients with COPD.

RELEVANCE TO CLINICAL PRACTICE

It is essential to identify distinct PA trajectories in patients with COPD to develop future interventions that promote PA.

NO PATIENT OR PUBLIC CONTRIBUTION

A national cohort study was used and no patients or the public were involved in the design and implementation of this study.

Leisure Participation and Cognitive Impairment Among Healthy Older Adults in China

Leisure participation is beneficial to various health outcomes. This study examined a comprehensive list of leisure activities in relation to incidence of cognitive impairment among healthy older adults (65+) in China. Using data from the 2002 to 2018 Chinese Longitudinal Healthy Longevity Survey, we found that most of the leisure activities were protective of cognitive decline and three leisure activities (watching TV, doing housework, and playing cards/mah-jong) stood out as the most important ones. Additionally, our results revealed subgroup variations in the association between leisure participation and cognitive function: Leisure activities such as reading newspapers/books (not significant for the illiterate), gardening (not significant for the illiterate), and regular exercise (not significant for the rural residents) had different effects across different demographic social groups. Our findings suggest that intervention programs designed to prevent cognitive decline for older adults should consider subgroup and cultural variations in order to yield the best outcomes.

Bidirectional Associations between Daytime Napping Duration and Metabolic Syndrome: A Nationally Representative Cohort Study

BACKGROUND

We aimed to examine the bidirectional associations between daytime napping duration and metabolic syndrome (MetS).

METHODS

Using data from the China Health and Retirement Longitudinal Study from 2011 to 2015, modified Poisson regression models were performed to explore the longitudinal associations of baseline napping duration with the occurrence and remission of MetS. Generalized estimating equation was conducted to explore the association between baseline MetS status with subsequent changes in daytime napping duration. Cross-lagged panel analysis was performed to further verify their bidirectional relationships.

RESULTS

During the four-year follow-up, among 5041 participants without MetS at baseline, extended naps were significantly associated with MetS occurrence, compared with non-napping. This association was only significant in individuals with adequate night-time sleep duration or good sleep quality of the 2898 participants with MetS at baseline. Excessive napping duration may be not favorable for MetS remission especially for adequate night-time sleepers. With respect to reverse associations, baseline MetS status significantly increased the napping duration during the subsequent follow-up period. Finally, there were significant bidirectional cross-lagged associations between napping duration and MetS severity score after adjusting for all covariates.

CONCLUSIONS

Our study indicates bidirectional relationships exist between daytime napping duration and MetS. Interestingly, longer napping duration was detrimental to cardiometabolic health only in those with sufficient night-time sleep duration or good sleep quality.

Impact of physical activity intensity on longitudinal trajectories of cognitive function and depressive symptoms in middle-aged and older Chinese adults: Eight-year prospective study

BACKGROUND

Little is known about how longitudinal trajectories of cognitive function and depressive symptoms are impacted by varying levels of physical activity (PA) intensity.

METHOD

The data were from the China Health and Retirement Longitudinal Study, a nationally representative household study of the Chinese population aged 45 years and older. The sample included 5025 middle-aged and older adults (mean age = 57) who self-reported their cognitive function, depressive symptoms, and PA intensity (vigorous PA, moderate PA, and light PA) every two years from 2011 to 2018.

RESULT

On average, every 2 years, cognitive function decreased by 0.17 points (95 % CI: [-0.22, -0.12], P < 0.05), while depressive symptoms increased by 0.23 points (95 % CI: [0.19,0.27], P < 0.001). Middle-aged and older adults who reported a minimum of 6 days/week frequency of moderate PA (β = 0.14, 95 % CI:[0.01,0.27]) had lower reduction of cognitive function compared to people with none moderate PA but not vigorous PA (β = 0.04, 95 % CI:[-0.11,0.19]) and light PA (β = 0.06, 95 % CI:[-0.09,0.22]). The increase in depressive symptoms was significantly slower among middle-aged and older adults with a minimum of 6 days/week light PA (β = -0.02, 95 % CI:[-0.03,-0.002]).

CONCLUSION

A minimum of 6 days of moderate PA a week was associated with a slower reduction in cognitive function and a minimum of 6 days of light PA a week was linked to a delayed increase in depressive symptoms. In middle-aged and older adults, a tailored PA intensity may be more beneficial in achieving the maximum improvement in cognitive function and mental health.

Moderate increase of serum uric acid within a normal range is associated with improved cognitive function in a non-normotensive population: A nationally representative cohort study

Background

Associations between serum uric acid (SUA) and changes in cognitive function are understudied in non-normotensive populations, and many previous studies only considered the baseline SUA at a single time point. We aimed to examine the effects of baseline SUA and 4-year changes in SUA on cognitive changes in the non-normotensive population.

Materials and methods

In the China Health and Retirement Longitudinal Study (CHARLS), cognitive function was measured based on executive function and episodic memory in four visits (years: 2011, 2013, 2015, and 2018). We identified two study cohorts from CHARLS. The first cohort included 3,905 non-normotensive participants. Group-based single-trajectory and multi-trajectory models were applied to identify 7-year cognitive trajectories. Adjusted ordinal logistics models were performed to assess the association between baseline SUA and 7-year cognitive trajectories, and subgroup analyses were conducted according to the presence of hyperuricemia or SUA levels. The second cohort included 2,077 eligible participants. Multiple linear regression was used to explore the effect of a 4-year change in SUA on cognitive change during the subsequent 3-year follow-up.

Results

Four distinct single-trajectories of global cognitive performance and four multi-trajectories of executive function and episodic memory were identified. Higher baseline SUA levels were significantly associated with more favorable cognitive single-trajectories (OR_{Q4 vs}. _Q1: 0.755; 95% CI: 0.643, 0.900) and multi-trajectories (OR_{Q4 vs}. _Q1: 0.784; 95% CI: 0.659, 0.933). Subgroup analyses revealed that the protective effect of SUA was significant in the non-hyperuricemia groups or the low-level SUA groups. Additionally, changes in SUA could influence future cognitive changes. Compared with non-hyperuricemia participants with elevated SUA, non-hyperuricemia participants with decreased SUA and patients with persistent hyperuricemia had a higher risk for cognitive decline. Furthermore, only the Q3 group of changes in SUA could enhance global cognitive function compared with the Q1 group (β: 0.449; 95% CI: 0.073, 0.826).

Conclusion

Our study indicates that the maintenance of normal SUA levels and a moderate increase of SUA were advantageous in improving cognitive function or trajectories in a non-normotensive population. Conversely, SUA may impair cognitive function in patients with persistent hyperuricemia.

Molecular Mechanisms of Exercise and Healthspan

Healthspan is the period of our life without major debilitating diseases. In the modern world where unhealthy lifestyle choices and chronic diseases taper the healthspan, which lead to an enormous economic burden, finding ways to promote healthspan becomes a pressing goal of the scientific community. Exercise, one of humanity's most ancient and effective lifestyle interventions, appears to be at the center of the solution since it can both treat and prevent the occurrence of many chronic diseases. Here, we will review the current evidence and opinions about regular exercise promoting healthspan through enhancing the functionality of our organ systems and preventing diseases.