Dose-Response Relation Between Physical Activity and Cognitive Function: Guangzhou Biobank Cohort Study

Associations between Physical Activity Frequency in Leisure Time and Subjective Cognitive Limitations in Middle-Aged Spanish Adults: A Cross-Sectional Study

There is a global ageing of the world's population. Ageing is associated with multiple pathologies, reductions in physical activity, and losses in cognitive function. This study aimed to analyse the associations between the frequency of leisure-time physical activity (PAF) in middle-aged Spaniards and subjective cognitive limitations (SCLs): self-reported problems for remembering or concentrating (data extracted from the 2017 National Health Survey and the 2020 European Health Survey in Spain). Furthermore, the study aimed to evaluate risk factors that could be related to a higher probability of developing SCLs. This was a cross-sectional study with 15,866 middle-aged Spaniards. The associations between FAP and SCLs were analysed using chi-square. Also, the risk factors for SCLs were evaluated using binary multiple logistic regression. The median age of participants was 55 years, with 49% men and 51% women. Associations were found between PAF and SCLs (p < 0.001). The highest prevalence of SCLs was found in physically inactive people and the lowest in very active people (13.7% vs. 5.8%, p < 0.05), and people with SCLs had a higher prevalence of inactivity than those without SCLs (47.2% vs. 33.8%, p < 0.05). Physical inactivity, low educational level, low social class, and being female were the main risk factors for SCLs. Among the actions to prevent cognitive limitations, as well as interventions in people with cognitive limitations, it would be advisable to include physical activity programmes, both as a preventive measure to delay cognitive limitations and to reduce the risk of other pathologies in people who already have them.

Association between intensity of physical activity and cognitive function in hypertensive patients: a case-control study

Previous studies have shown that a higher intensity of physical activity (PA) is associated with a lower risk of cognitive impairment (CI), whereas hypertension is associated with higher CI. However, there are few studies on the association between PA intensity and cognitive function in hypertensive patients. This study investigated the association between PA intensity and cognitive function in hypertensive patients. A total of 2035 hypertensive patients were included in this study, including 407 hypertensive patients with CI and 1628 hypertensive patients with normal cognitive function matched 1:4 by age and sex. The International Physical Activity Questionnaire-Long Form and the Mini-mental State Examination were used to evaluate PA intensity, total metabolic equivalents, and cognitive function in patients with hypertension. Multivariate logistic regression was used to analyze the correlation between PA intensity and CI in hypertensive patients. The Spearman correlation coefficient was used to analyze the correlation between PA intensity and the total score of each component of the MMSE and the correlation between PA total metabolic equivalents and cardiac structure in hypertensive patients. After adjusting for all confounding factors, PA intensity was negatively associated with CI in hypertensive patients (OR = 0.608, 95% CI: 0.447-0.776, P < 0.001), and this association was also observed in hypertensive patients with education level of primary school and below and junior high school and above (OR = 0.732, 95% CI: 0.539-0.995, P = 0.047; OR = 0.412, 95% CI: 0.272-0.626, P < 0.001). The intensity of PA in hypertensive patients was positively correlated with orientation (r = 0.125, P < 0.001), memory (r = 0.052, P = 0.020), attention and numeracy (r = 0.151, P < 0.001), recall ability (r = 0.110, P < 0.001), and language ability (r = 0.144, P < 0.001). PA total metabolic equivalents in hypertensive patients were negatively correlated with RVEDD and LAD (r = - 0.048, P = 0.030; r = - 0.051, P = 0.020) and uncorrelated with LVEDD (r = 0.026, P = 0.233). Higher PA intensity reduced the incidence of CI in hypertensive patients. Therefore, hypertensive patients were advised to moderate their PA according to their circumstances.

Associations of cognitive impairment and longitudinal change in cognitive function with the risk of fatal stroke in middle-aged to older Chinese

It is unclear whether cognitive impairment and the longitudinal change in cognition are associated with the risk of fatal stroke in aging populations. Based on the Guangzhou Biobank Cohort Study data a sum of 26,064 participants at baseline and all deaths caused by stroke in a mean follow-up of 14.3 years (standard deviation = 3.2) were included, and the Cox proportional hazard regression was used in this prospective cohort study. Cognitive impairment was respectively associated with an increased risk of fatal strokes (the adjusted hazard ratio (aHR) = 1.38, 95% CI1.16-1.64, P < 0.001) and fatal ischaemic stroke (aHR = 1.39, 95% CI1.10-1.77, P = 0.007), compared to median cognition; the Delayed Word Recall Test (DWRT) score was associated with a decreasing trend for the risk of fatal strokes in a restricted cubic spline analysis; the longitudinal DWRT score decline was associated with the increased risks of fatal strokes (aHR = 1.42, 95% CI 1.11-1.82, P = 0.006) and fatal haemorrhagic stroke (aHR = 1.75, 95% CI 1.10-2.78, P = 0.02), compared to the longitudinal DWRT score rise. In summary, cognitive impairment and the longitudinal decline in DWRT scores were associated with the increased risk of fatal strokes; early screening of cognitive function should be conducive to predictive intervention in fatal stroke among relatively healthy middle-aged to older populations.

Relationship Between Cognitive Performance, Physical Activity, and Socio-Demographic/Individual Characteristics Among Aging Americans

BACKGROUND

Physical activity (PA) has emerged as a promising approach to delay Alzheimer's disease and related dementias, but the optimal intensity of PA to improve cognitive health remains unknown.

OBJECTIVE

To evaluate the association between duration and intensity of PA and cognitive domains (executive function, processing speed, and memory) in aging Americans.

METHODS

Linear regressions in hierarchical blocks for variable adjustment and the size of effect (η2) were analyzed by using the data of 2,377 adults (age = 69.3±6.7 years) from the NHANES 2011-2014.

RESULTS

Participants with 3-6 h/week of vigorous- and > 1 h/week of moderate-intensity PA scored significantly higher in executive function and processing speed domains of cognition compared to inactive peers (η2 = 0.005 & 0.007 respectively, p < 0.05). After adjustment, the beneficial effects of 1-3 h /week of vigorous-intensity PA became trivial for delayed recall memory domain test scores (β= 0.33; 95% CI: -0.01,0.67; η2 = 0.002; p = 0.56). There was no linear dose-response relationship between the cognitive test scores and weekly moderate-intensity of PA. Interestingly, higher handgrip strength and higher late-life body mass index were associated with a higher performance across all cognitive domains.

CONCLUSION

Our study supports habitual PA with superior cognition health in some but not all domains among older adults. Furthermore, increased muscle strength and higher late-life adiposity may also impact cognition.

Genetic loci, rs17817449 and rs6567160, known for obesity and the risk of stroke events among middle-aged and older Chinese people

BACKGROUND

Fat Mass and Obesity-Associated (FTO) and the Melanocortin-4 Receptor (MC4R) genes are strongly associated with obesity, an established risk factor for stroke. We aimed to assess the associations between rs17817449 at the FTO and rs6567160 at the MC4R and the risk of stroke events in middle-aged and older Chinese people.

MATERIALS AND METHODS

Study data were obtained from the Guangzhou Biobank Cohort Study; a total of 148 participants with a self-reported history of stroke and an equal volume of age- and sex-matched participants were selected as the cases and the controls in a case-control study; a total of 13,967 participants at the first follow-up and all participants with fatal stroke (up to April 2021) were included in a retrospective cohort study. Conditional logistic regression and the Cox proportional hazards regression analyses were used to assess the associations of the two genetic loci with the risk of stroke events.

RESULTS

After adjusting for age, sex, education, job, smoking, alcohol consumption, body mass index, physical activity, hypertension, diabetes, and dyslipidemia, rs17817449 and rs6567160 shared minor alleles G and C, respectively, in the case-control analyses. The genotypes GG+GT of rs17817449 at the FTO were significantly associated with a decreased risk of fatal stroke occurrence, with fatal all strokes having an adjusted hazard ratio (aHR) of 0.71 (95% confidence intervals (CI) 0.52-0.97, P = 0.04) and fatal ischemic stroke having an aHR of 0.64 (95% CI 0.41-1.00, P = 0.05), when the genotype TT was taken as a reference and a series of multiplicities were adjusted; the risk of fatal all strokes was lowered by dyslipidemia (aHR = 0.63, 95% CI 0.39-1.00, P = 0.05) and non-diabetes (aHR = 0.68, 95% CI 0.46-0.99, P = 0.049) in the retrospective cohort analyses. Significances were observed neither in the associations between rs6567160 and the risk of stroke events nor in an interaction between rs17817449 and rs6567160 in the two-stage analyses.

CONCLUSION

The G allele of rs17817449 at the FTO, not rs6567160 at the MC4R, was associated with a decreased risk of fatal stroke occurrence; its functional role in stroke should be explored in relatively healthy middle-aged to older Chinese people.

Twenty-four-hour time-use composition and cognitive function in older adults: Cross-sectional findings of the ACTIVate study

Introduction

Physical activity, sedentary behaviour and sleep are associated with cognitive function in older adults. However, these behaviours are not independent, but instead make up exclusive and exhaustive components of the 24-h day. Few studies have investigated associations between 24-h time-use composition and cognitive function in older adults. Of these, none have considered how the quality of sleep, or the context of physical activity and sedentary behaviour may impact these relationships. This study aims to understand how 24-h time-use composition is associated with cognitive function across a range of domains in healthy older adults, and whether the level of recreational physical activity, amount of television (TV) watching, or the quality of sleep impact these potential associations.

Methods

384 healthy older adults (age 65.5 ± 3.0 years, 68% female, 63% non-smokers, mean education = 16.5 ± 3.2 years) participated in this study across two Australian sites (Adelaide, n = 207; Newcastle, n = 177). Twenty-four-hour time-use composition was captured using triaxial accelerometry, measured continuously across 7 days. Total time spent watching TV per day was used to capture the context of sedentary behaviours, whilst total time spent in recreational physical activity was used to capture the context of physical activity (i.e., recreational accumulation of physical activity vs. other contexts). Sleep quality was measured using a single item extracted from the Pittsburgh Sleep Quality Index. Cognitive function was measured using a global cognition index (Addenbrooke's Cognitive Examination III) and four cognitive domain composite scores (derived from five tests of the Cambridge Neuropsychological Test Automated Battery: Paired Associates Learning; One Touch Stockings of Cambridge; Multitasking; Reaction Time; Verbal Recognition Memory). Pairwise correlations were used to describe independent relationships between time use variables and cognitive outcomes. Then, compositional data analysis regression methods were used to quantify associations between cognition and 24-h time-use composition.

Results

After adjusting for covariates and false discovery rate there were no significant associations between time-use composition and global cognition, long-term memory, short-term memory, executive function, or processing speed outcomes, and no significant interactions between TV watching time, recreational physical activity engagement or sleep quality and time-use composition for any cognitive outcomes.

Discussion

The findings highlight the importance of considering all activities across the 24-h day against cognitive function in older adults. Future studies should consider investigating these relationships longitudinally to uncover temporal effects.

Association of Hand Grip Strength with Mild Cognitive Impairment in Middle-Aged and Older People in Guangzhou Biobank Cohort Study

Background: Lower hand grip strength has been linked to cognitive impairment, but studies in older Chinese are limited. We examined the association of hand grip strength with cognitive function in a large sample of older Chinese. Methods: 6806 participants aged 50+ years from the Guangzhou Biobank Cohort Study (GBCS) were included. Relative grip strength was calculated by absolute handgrip strength divided by the body mass index (BMI). Cognitive function was assessed using the Delayed Word Recall Test (DWRT, from 0 to 10) and the Mini Mental State Examination (MMSE, from 0 to 30), with higher scores indicating better cognition. Results: After adjusting for multiple potential confounders, lower absolute grip strength and relative grip strength were significantly associated with lower DWRT (all p < 0.05) in all participants. No significant interaction effects between sex and handgrip strength on cognitive impairment were found (p from 0.27 to 0.87). No significant association between handgrip strength and total MMSE scores was found in the total sample or by sex (p from 0.06 to 0.50). Regarding the individual components of MMSE, lower absolute and relative grip strength were significantly associated with lower scores of the recall memory performance in all participants (p from 0.003 to 0.04). Conclusion: We have shown for the first time a positive association of grip strength with recall memory performance, but not general cognitive function in older people, which warrants further investigation.

Interplay between cognition and weight reduction in individuals following a Mediterranean Diet: Three-year follow-up of the PREDIMED-Plus trial

BACKGROUND & AIMS

Some cognitive profiles might facilitate successful weight loss and its maintenance. Also, weight reductions may result in cognitive benefits. However, little work to date has examined the interactions between cognition and weight changes in the context of interventions with the Mediterranean diet (MedDiet). We studied the within-subject longitudinal relationships between cognition, body mass index (BMI), physical activity (PA), and quality of life (QoL), in older adults following a MedDiet.

METHODS

The PREDIMED-Plus is a primary prevention trial testing the effect of a lifestyle intervention program with an energy-restricted MedDiet (er-MedDiet), weight-loss goals and PA promotion on cardiovascular disease. The PREDIMED-Plus-Cognition sub-study included 487 participants (50% women, mean age 65.2 ± 4.7 years), with overweight/obesity, metabolic syndrome and normal cognitive performance at baseline. A comprehensive neurocognitive test battery was administered at baseline and after 1 and 3 years.

RESULTS

Baseline higher performance in verbal memory (OR = 1.5; 95%CI 1.0, 2.1), visuoconstructive praxis and attention (OR = 1.5; 95%CI 0.9, 2.3), and inhibition (OR = 1.3; 95%CI 0.9, 1.9) were associated with a higher odd of achieving at least 8% weight loss after 3 years follow-up in participants randomized to the intervention group. There were moderate improvements in specific tests of memory and executive functions during follow-up. Higher adherence to the er-MedDiet was associated with greater improvements in memory. Women exhibited lower rates of change in global cognition, PA and QoL. Moreover, improvements in memory correlated with reductions in BMI after 1 year (β_STD = -0.14) and with improvements in PA after 3 years (β_STD = 0.13). Finally, participants who experienced greater improvements in executive functions and global cognition also experienced greater improvements in their QoL.

CONCLUSIONS

This study refines the understanding of the determinants and mutual interrelationships between longitudinally-assessed cognitive performance and weight loss, adding further evidence to the cognitive benefits associated with better adherence to a MedDiet. Our results also suggest that weight loss interventions tailored to the cognitive profile and gender of participants are promising avenues for future studies.

Glycaemia and hand grip strength in aging people: Guangzhou biobank cohort study

BACKGROUND

There is a link between hyperglycemia and mechanical functions of muscle. However, existing evidence of the association between hyperglycemia and weaker muscle strength is limited and inconsistent. We examined whether glycemic status was associated with relative grip strength (RGS) in older Chinese.

METHODS

In 2008-2012, 9180 participants (2516 men and 6664 women) from the Guangzhou Biobank Cohort Study had fasting and 2-h post-load glucose measured. Glycemic status was categorized as normoglycaemia, prediabetes (i.e., impaired fasting glucose and/or impaired glucose tolerance) and diabetes. RGS was assessed using a Jamar Hydraulic Hand Dynamometer divided by body mass index. General linear model was used to assess the association of glycemic status with RGS.

RESULTS

After adjusting for age, smoking status, alcohol use, physical activity, health status, body fat percentage and waist circumference, in men, hyperglycemia was associated with a lower RGS, with the RGS being 1.38 (95% confidence interval (CI) = 1.34, 1.42) in normoglycaemia, 1.35 (95% CI = 1.30, 1.39) in prediabetes, 1.33 (95% CI = 1.29, 1.38) in newly diagnosed diabetes and 1.32 (95% CI = 1.27, 1.37) in known diabetes (P for trend < 0.001). The association of glycemic status with RGS was non-significant in women. Among the normoglycaemic group, no association was found between fasting glucose and RGS in men, whereas a significantly inverse association was found in women, with adjusted β for RGS per mmol/l increase in fasting glucose being - 0.05 to - 0.04 (P values from 0.002 to 0.03).

CONCLUSIONS

Higher fasting glucose was associated with reduced grip strength in a dose-response manner, and the association was significant even in women with normoglycaemia. Our findings suggest that lowering glucose across the whole range might be important in preserving muscle strength, especially in aging women.

Exploring Active Travel and Leisure-Time Physical Activity Relationships With Cognition Among Older Adults

Leisure-time physical activity (LTPA) is known to benefit cognition among older adults, but the impact of active travel is unclear. To explore this relationship, data from the 2011-2014 National Health and Nutritional Examination Survey (N = 2,702; mean age = 70) were retrieved on the self-reported frequency and duration of active travel (walking/cycling for transport, >20 min), LTPA engagement (e.g., sport), and three cognitive outcomes. Four groups were created according to physical activity guidelines (600 metabolic equivalent of task/week): inactive (n = 1,790), active travelers (n = 210), engaging in LTPA (n = 579), and engaging in both (n = 123). Analysis of covariance (and follow-up comparisons) revealed a significant main effect for each cognition variable, after adjusting for the covariates, indicating that those engaging in LTPA performed the best. Although correlational, these findings suggest that LTPA engagement may be important for cognition among older adults, but active travel did not provide added benefit.

Physical fitness and physical activity association with cognitive function and quality of life: baseline cross-sectional analysis of the PREDIMED-Plus trial

Physical activity (PA) has been hypothesized to be effective to maintaining cognitive function and delay cognitive decline in the elderly, but physical fitness (PF) could be a better predictor of cognitive function. We aimed to study the association between PA and PF with cognitive function and quality of life using cross-sectional data from 6874 participants of the PREDIMED-Plus trial (64.9 ± 4.9 years, 48.5% female). PF and PA were measured with a Chair Stand Test, the REGICOR and Rapid Assessment Physical Activity questionnaires. Cognitive function was measured with Mini-mental State Examination, Control Oral Word Association Test, Trail Making Test and Digit Span tests; whereas health-related quality of life was assessed with the SF36-HRQL test. Cognitive and quality of life scores were compared among PF quartiles and PA levels (low, moderate and high) with ANCOVA and with Chair Stand repetitions and energy expenditure from total PA with multivariable linear regression adjusted for confounding factors. PF associated with higher scores in phonemic and semantic verbal fluency tests and with lower TMT A time. However, PA was not associated with the neurocognitive parameters evaluated. Both PF and PA levels were strongly associated with a better quality of life. We concluded that PF, but not PA, is associated with a better cognitive function. This trial was retrospectively registered at the International Standard Randomized Controlled Trial (ISRCTN89898870, https://www.isrctn.com/ISRCTN89898870?q=ISRCTN89898870&filters=&sort=&offset=1&totalResults=1&page=1&pageSize=10&searchType=basic-search) on 07/24/2014.

Non-communicable Diseases and Cognitive Impairment: Pathways and Shared Behavioral Risk Factors Among Older Chinese

Population aging has brought about a number of challenges to public health and primary health care systems due to increases in the prevalence of non-communicable diseases (NCDs). As a country with one of the largest populations globally, China is confronting a rising number of chronic NCDs including cardiometabolic related conditions. This mini-review investigates the link between NCDs and cognitive impairment through common risk factors. Identifying risk factors is important for the prevention and management of these chronic conditions. In addition, this review also identifies the role of primary health care services in reducing behavioral risk factors for NCDs and cognitive impairment. Addressing shared determinants and pathways is important in the design of public health interventions and primary health care services in China. Monitoring and management of NCD biomarkers and behavioral risk factors may also be beneficial for cognitive health among older Chinese.

Physical Activity, Decision-Making Abilities, and Eating Disturbances in Pre- and Postbariatric Surgery Patients

BACKGROUND

Physical activity (PA) is considered to have a beneficial influence on executive functioning, including decision-making. Enhanced decision-making after bariatric surgery may strengthen patients' ability to delay gratification, helping to establish appropriate eating behavior. The objectives of this study were to (1) compare a preoperative group with a postoperative group with regard to daily PA, decision-making, and eating disturbances; and (2) investigate the relationship between these variables.

METHODS

The study included 71 bariatric surgery candidates (78 % women, BMI [kg/m²] M = 46.9, SD = 6.0) and 73 postoperative patients (78 % women, BMI M = 32.0, SD = 4.1; 89 % Roux-en-Y gastric bypass, 11 % sleeve gastrectomy; months postoperative M = 8.2, SD = 3.5; total weight loss [%] M = 33.2, SD = 8.9) who completed SenseWear Pro₂ activity monitoring. Decision-making was assessed using a computerized version of the Iowa Gambling Task and eating disorder psychopathology using the Eating Disorder Examination-Questionnaire.

RESULTS

The number of patients who were classified as physically inactive was similarly high in the pre- and postoperative groups. No group differences emerged with regard to decision-making, but the postoperative group exhibited less eating disturbances than the preoperative group. No significant associations were found between PA, decision-making, and eating behavior.

CONCLUSIONS

Patients after bariatric surgery were not more physically active than bariatric surgery candidates, which should be considered in care programs. Additionally, future research is needed to explore the possible link between PA, patients' decision-making abilities, and eating disturbances concerning dose-response questions.

Physical inactivity and cognitive impairment in Korean older adults: gender differences in potential covariates

BACKGROUND

Physical inactivity is one major lifestyle risk factor of mild cognitive impairment with ageing.

AIM

To investigate whether or not potential covariates modulate the association between physical activity (PA) and cognitive impairment in older adults.

SUBJECTS AND METHODS

Data from 10 245 Korean older adults (5817 women) were used.

RESULTS

High PA older adults were younger and longer educated and had lower comorbidity and depression than low PA older adults. Compared with low PA men, moderate PA men only had a significantly lower odds-ratio (OR) and 95% confidence interval (95% CI) (OR = 0.795, 95% CI = 0.654 ∼ 0.965, p = 0.021) for having cognitive impairment, even after adjusting for measured covariates, which was no longer significant when additionally adjusted for comorbidity (OR = 0.862, 95% CI = 0.707 ∼ 1.051, p = 0.143). Compared with low PA women, moderate and high PA women had significantly lower risks of cognitive impairment (OR = 0.830, 95% CI = 0.712 ∼ 0.969, p = 0.018 and OR = 0.784, 95% CI = 0.651 ∼ 0.943, p = 0.010, respectively), even after adjusting for the measured covariates including comorbidity, which was no longer significant when additionally adjusted for depression (OR = 0.897, 95% CI = 0.776 ∼ 1.049, p = 0.173 and OR = 0.919, 95% CI = 0.761 ∼ 1.111, p = 0.385, respectively).

CONCLUSION

These findings suggest that gender differences in the covariates modulate the relationship between physical activity and cognitive decline in older Korean adults.

Mendelian randomization estimates of alanine aminotransferase with cardiovascular disease: Guangzhou Biobank Cohort study

Observational studies of the association of alanine aminotransferase (ALT) levels with ischaemic heart disease (IHD) and cardiovascular disease (CVD) risk factors are inconsistent, probably because of confounding and reverse causality. Mendelian randomization (MR) provides less confounded results. We used MR analysis to assess the associations of ALT (U/L) with IHD, diabetes and other CVD risk factors. We used instrumental variable analysis based on two single nucleotide polymorphism (SNPs) HSD17B13/MAPK10 (rs6834314) and PNPLA3/SAMM50 (rs738409) to assess the associations of ALT (U/L) with IHD, diabetes and other CVD risk factors in the Guangzhou Biobank Cohort Study (GBCS). Observationally in 19,925 participants ALT levels were strongly positively associated with self-reported IHD, systolic and diastolic blood pressure, low-density lipoprotein- and total cholesterol, triglycerides, fasting glucose, body mass index, waist circumference, heart rate (HR) and diabetes, but were not associated with uncorrected QT interval, HR-corrected QT interval or high-density lipoprotein-cholesterol. In the MR study, using a credible genetic instrument (F-statistic = 23) for ALT, ALT levels were negatively associated with IHD (odds ratio (OR) 0.92, 95% confidence interval (CI) 0.87 to 0.97) and triglycerides (β - 0.08, 95% CI - 0.13 to - 0.03), but were not associated with other CVD risk factors. Our results using Mendelian randomization suggest that ALT reduces the risk of IHD, probably through reducing triglyceride levels. The underlying mechanisms deserve further investigation.

Masters Athletes: Exemplars of Successful Aging?

Global population aging has raised academic interest in successful aging to a public policy priority. Currently there is no consensus regarding the definition of successful aging. However, a synthesis of research shows successful aging can be defined as a late-life process of change characterized by high physical, psychological, cognitive, and social functioning. Masters athletes systematically train for, and compete in, organized forms of team and individual sport specifically designed for older adults. Masters athletes are often proposed as exemplars of successful aging. However, their aging status has never been examined using a comprehensive multidimensional successful aging definition. Here, we examine the successful aging literature, propose a successful aging definition based on this literature, present evidence which suggests masters athletes could be considered exemplars of successful aging according to the proposed definition, and list future experimental research directions.

Dose-Response Association Between Physical Activity and Cognitive Function in a National Sample of Older Adults

PURPOSE

Previous research demonstrates a favorable effect of physical activity on cognitive function among older adults. The potential dose-response relationship between physical activity and cognitive function in this population is less understood, which was the purpose of this study.

SETTING

Data from the 1999 to 2002 National Health and Nutrition Examination Survey were employed.

PARTICIPANTS

A total of 2157 older adults aged 60 to 85 years.

MEASURES

Cognitive function was assessed from the Digit Symbol Substitution Test. Moderate-to-vigorous physical activity (MVPA), expressed as metabolic equivalent of task (MET)-min-month (MET-min-month = days × duration × MET level), was assessed via self-report, with 5 MVPA categories evaluated: (1) <2000 MVPA MET-min-month, (2) 2000 to 3999 MVPA MET-min-month, (3) 4000 to 5999 MVPA MET-min-month, (4) 6000 to 7999 MVPA MET-min-month, and (5) 8000+ MVPA MET-min-month.

ANALYSIS

Weighted multivariable linear regression.

RESULTS

An inverted U-shaped relationship was observed. Consistent across several adjusted models, those who engaged in 6000 to 7999 MVPA MET-min-month had the highest cognitive function score.

CONCLUSION

The results suggest an optimal amount of physical activity to prevent the cognitive decline associated with aging.

Physical activity and cognitive function among older adults in China: A systematic review

BACKGROUND

Physical activity (PA) has been shown to benefit cognitive function in older adults. However, the cognitive benefits of exercising for older Chinese adults have not been systematically documented. This study was to conduct a systematic review on evidence that PA is beneficial for cognitive functioning in older Chinese adults.

METHODS

Major databases, including PubMed, EMBASE, Cochrane Library, WanFang, CNKI, and VIP, were searched for studies published in English or Chinese between January 2000 and December 2015. Randomized and non-randomized controlled trials (RCTs and non-RCTs), cohort, case-control and cross-sectional studies that evaluated PA and cognitive function among older Chinese adults were included in this review.

RESULTS

Of 53 studies included and reviewed, 33 were observational (22 cross-sectional, 7 case-control, and 4 cohort) and 20 were experimental (15 RCTs, 5 non-RCTs). Observational studies showed an association of reduced risk of cognitive-related diseases (i.e., mild cognitive impairment, Alzheimer's disease, and dementia) through PA, whereas experimental studies reported exercise-induced improvement in multiple domains of cognitive function (i.e., global cognitive function, memory, executive function, attention, language, and processing recourse).

CONCLUSION

This systematic review provides initial evidence that PA may benefit cognition in older Chinese adults. Further studies of individuals with cognitive impairments and prospective and RCT studies having high scientific rigor are needed to corroborate the findings reported in this review.

Muscles, Ligaments and Tendons Journal - Basic principles and recommendations in clinical and field Science Research: 2016 Update

The proper design and implementation of a study as well as a balanced and well-supported evaluation and interpretation of its main findings are of crucial importance when reporting and disseminating research. Also accountability, funding acknowledgement and adequately declaring any conflict of interest play a major role in science. Since the Muscles, Ligaments and Tendons Journal (MLTJ) is committed to the highest scientific and ethical standards, we encourage all Authors to take into account and to comply, as much as possible, to the contents and issues discussed in this official editorial. This could be useful for improving the quality of the manuscripts, as well as to stimulate interest and debate and to promote constructive change, reflecting upon uses and misuses within our disciplines belonging to the field of "Clinical and Sport - Science Research".

Physical activity is unrelated to cognitive performance in pre-bariatric surgery patients

OBJECTIVE

To investigate the relationship between physical activity (PA) and cognitive performance in extreme obesity.

METHODS

Seventy-one bariatric surgery candidates (77.5% women) with a mean body mass index (BMI) of 46.9 kg/m2 (SD=6.0) and a mean age of 41.4 (SD=11.9) years completed SenseWear Pro2 activity monitoring for seven days. Cognitive functioning was assessed by a computerized test battery including tasks of executive function (Iowa Gambling Task), visuospatial short-term memory (Corsi Block Tapping Test) and verbal short-term memory (Auditory-Verbal Learning Test). Questionnaires assessing eating disturbances and depressive symptoms were administered. Somatic comorbidities were assessed by medical chart review.

RESULTS

The level of PA was low with mean steps per day within wear time being 7140 (SD=3422). Most patients were categorized as sedentary (31.0%) or low active (26.8%). No significant association between PA estimates and cognitive performance was found. Lower PA was modestly correlated with higher BMI but not with age, somatic comorbidity or depressive symptoms. Moderated regression analyses suggested a significant interaction effect between depression and PA in predicting performance on the Corsi Block Tapping Test. Patients with (29.6%) and without (70.4%) regular binge eating did not differ with respect to PA or cognitive function.

CONCLUSION

The findings indicate no association between daily PA and cognitive performance in morbidly obese patients. Future studies should explore the relationship between the variables with regard to dose-response-questions, a broader BMI range and with respect to potential changes after substantial weight loss due to bariatric surgery.

Liver enzymes and incident diabetes in China: a prospective analysis of 10 764 participants in the Guangzhou Biobank Cohort Study

BACKGROUND

Impaired liver function has been shown to be associated with incident diabetes. The independent role of the different liver enzymes, including γ-glutamyltransferase (GGT), alanine transaminase (ALT) and aspartate transaminase (AST), has not been addressed properly, taking into account their high collinearity. We used partial least squares (PLS) regression to identify the contribution of ALT, AST and GGT, which appears causally associated with diabetes as a validation factor, to incident diabetes in a South China population where liver impairment and diabetes are common.

METHODS

Participants were from the Guangzhou Biobank Cohort Study recruited in 2003-2008, with follow-up re-examination up to the end of 2012. Multivariable generalised linear models and PLS were used to examine the adjusted associations of ALT, AST and GGT with diabetes. Incident diabetes was defined as self-reported diabetes, and/or initiation of hypoglycaemia medication or insulin during follow-up, or fasting glucose ≥7.0 mmol/L, or 2 h oral glucose tolerance test, glucose ≥11.1 mmol/L at follow-up examination.

RESULTS

In 10 764 Chinese participants aged ≥50 years with no diabetes at baseline, 1228 (11.4%) developed diabetes during the median 4 years of follow-up. Using PLS, the risk for incident diabetes was higher by 18% (95% CI 8% to 27%) per 1 SD increment in log-ALT, and expectedly higher by 36% (95% CI 26% to 52%) for log-GGT, adjusted for age, sex, education, smoking, alcohol, physical activity, waist circumference and body mass index. Similarly adjusted, no association for log-AST (relative risk 0.92, 95% CI 0.85 to 1.01) was found.

CONCLUSIONS

ALT but not AST was associated with incident diabetes. Further experimental studies are needed to confirm the causal association and clarify the underlying mechanisms.

Sleep duration and memory in the elderly Chinese: longitudinal analysis of the Guangzhou Biobank Cohort Study

STUDY OBJECTIVES

Previous cross-sectional studies showed that short or long sleep duration was associated with memory impairment (MI), but longitudinal studies are scarce. We examined whether sleep duration was associated with memory decline or development of MI.

DESIGN SETTING PARTICIPANTS

We conducted a prospective analysis based on the Guangzhou Biobank Cohort Study on 13,888 participants aged 50+ years without MI at baseline and with a follow-up for a mean of 4.1 years.

MEASURES AND RESULTS

Memory decline was assessed using the Delayed 10-Word Recall Test (DWRT), and in a subset (n = 6,020) with the Mini-Mental State Examination (MMSE). Short and long sleep duration was defined as ≤ 5 hours/day and ≥ 9 hours/day, respectively. Data were analyzed both continuously for memory decline and dichotomously for MI (independently defined as DWRT, < 4; MMSE, < 25). After adjusting for multiple potential confounders, both short and long sleep durations were associated with memory decline using DWRT or MMSE score changes (all P < 0.001). Seven percent (n = 980) developed DWRT-defined MI and 4.0% (n = 194) MMSE-defined MI during the follow-up. Only those with a short (≤ 5 h/day) sleep duration had a significantly increased risk of DWRT-defined MI (odds ratio = 1.53 (95% confidence interval; 1.21-1.93); P < 0.001) relative to normal sleepers (7 h/day). The association remained significant after excluding those with poor self-reported health. No associations were observed with MMSE-defined MI for both long and short sleep durations.

CONCLUSIONS

This is the largest study to date addressing the association between extremes of sleep duration and memory decline. The observed adverse relationships provide support for an intervention study to examine the potential benefits of normalizing sleep duration in attenuating memory decline.

Education and WHO recommendations for fruit and vegetable intake are associated with better cognitive function in a disadvantaged Brazilian elderly population: a population-based cross-sectional study

Brazil has one of the fastest aging populations in the world and the incidence of cognitive impairment in the elderly is expected to increase exponentially. We examined the association between cognitive impairment and fruit and vegetable intake and associated factors in a low-income elderly population. A cross-sectional population-based study was carried out with 1849 individuals aged 65 or over living in São Paulo, Brazil. Cognitive function was assessed using the Community Screening Instrument for Dementia (CSI-D). Fruit and vegetable intake was assessed with a Food Frequency Questionnaire (FFQ) and categorized into quartiles of intake and into total daily fruit and vegetable intake using the cut-off points for the WHO recommendations (<400grams/day or ≥400 grams/day). The association between cognitive impairment and each quartile of intake, and WHO recommendation levels, was evaluated in two separate multivariate logistic models. The WHO recommendations for daily intakes ≥400 grams/day were significantly associated with 47% decreased prevalence of cognitive impairment. An effect modification was found in both models between cognitive impairment and “years of education and physical activity” and “years of education and blood levels of HDL” So that, having 1 or more years of education and being physically active or having 1 or more years of education and levels higher than 50 mg/dl of HDL-cholesterol strongly decreased the prevalence of cognitive impairment. In this socially deprived population with very low levels of education and physical activity and fruit and vegetable intake, those who attained WHO recommendations, had 1 year or more of education and were physically active had a significantly lower prevalence of cognitive impairment. A more comprehensive understanding of the social determinants of mental health is needed to develop effective public policies in developing countries.

Traumatic brain injury and post-acute decline: what role does environmental enrichment play? A scoping review

Objectives: While a growing number of studies provide evidence of neural and cognitive decline in traumatic brain injury (TBI) survivors during the post-acute stages of injury, there is limited research as of yet on environmental factors that may influence this decline. The purposes of this paper, therefore, are to (1) examine evidence that environmental enrichment (EE) can influence long-term outcome following TBI, and (2) examine the nature of post-acute environments, whether they vary in degree of EE, and what impact these variations have on outcomes.

Methods: We conducted a scoping review to identify studies on EE in animals and humans, and post-discharge experiences that relate to barriers to recovery.

Results: One hundred and twenty-three articles that met inclusion criteria demonstrated the benefits of EE on brain and behavior in healthy and brain-injured animals and humans. Nineteen papers on post-discharge experiences revealed that variables such as insurance coverage, financial, and social support, home therapy, and transition from hospital to home, can have an impact on clinical outcomes.

Conclusion: There is evidence to suggest that lack of EE, whether from lack of resources or limited ability to engage in such environments, may play a role in post-acute cognitive and neural decline. Maximizing EE in the post-acute stages of TBI may improve long-term outcomes for the individual, their family and society.

Psychological functioning and adherence to the recommended dose of physical activity in later life: results from a national health survey

BACKGROUND

Official health organizations have established the dose of physical activity needed for preserving both physical and psychological health in old age. The objective of this study was to explore whether adherence to the recommended criterion of physical activity accounted for better psychological functioning in older adults in Israel.

METHODS

A random sample of 1,663 (799 men) Israelis reported their physical activity routine, and based on official guidelines were divided into sufficiently active, insufficiently active, and inactive groups. The General Health Questionnaire (GHQ) was used for assessing mental health and the Mini-Mental State Examination (MMSE) for assessing cognitive functioning.

RESULTS

Factor analysis performed on the GHQ yielded two factors - positive and negative. Logistic regressions for the GHQ factors and for the MMSE were conducted for explaining their variance, with demographic variables entered first, followed by health and then physical activity. The explained variance in the three steps was Cox and Snell R2 = 0.022, 0.023, 0.039 for the positive factor, 0.066, 0.093, 0.101 for the negative factor, and 0.204, 0.206, 0.209 for the MMSE.

CONCLUSIONS

Adherence to the recommended dose of physical activity accounted for better psychological functioning beyond demographic and health variables; however, the additional explained variance was small. More specific guidelines of physical activity may elucidate a stronger relationship, but only randomized controlled trials can reveal cause-effect relationship between physical activity and psychological functioning. More studies are needed focusing on the positive factor of psychological functioning.