Grip Strength Is Associated With Cognitive Performance in Schizophrenia and the General Population: A UK Biobank Study of 476559 Participants

Aberrant preparation of hand movement in schizophrenia spectrum disorder: an fMRI study

Schizophrenia spectrum disorder is linked to impaired self-other distinction and action feedback monitoring, largely stemming from sensory-motor predictive mechanisms. However, the neural correlates of these predictive processes during movement preparation are unknown. Here, we investigated whether patients with schizophrenia spectrum disorder exhibit aberrant sensory-motor predictive processes reflected in neural activation patterns prior to hand movement onset. Functional MRI data from patients with schizophrenia spectrum disorder (n = 20) and healthy controls (n = 20) were acquired during actively performed or passively induced hand movements. The task required participants to detect temporal delays between their movements and video feedback, which either displayed their own (self) or someone else's (other) hand moving in accordance with their own hand movements. Patients compared with healthy controls showed reduced preparatory blood-oxygen-level-dependent activation (active > passive) in clusters comprising the left putamen, left insula, left thalamus and lobule VIII of the right cerebellum. Reduced activation in the left insula and putamen was specific to own-hand feedback. Additionally, patients with schizophrenia spectrum disorder revealed reduced suppression (passive > active) in bilateral and medial parietal (including the right angular gyrus) and occipital areas, the right postcentral gyrus, cerebellum crus I, as well as the left medial superior frontal gyrus. Ego-disturbances were negatively correlated with left insula and putamen activation during active conditions and with right angular gyrus activation patterns during passive conditions when own-hand feedback was presented. These functional MRI findings suggest that group differences are primarily evident during preparatory processes. Our results show that this preparatory neural activation is further linked to symptom severity, supporting the idea that the preparation of upcoming events as internal predictive mechanisms may underlie severe symptoms in patients with schizophrenia spectrum disorder. These findings could improve our understanding of deficits in action planning, self-monitoring and motor dysfunction in various psychiatric, neurological and neurodegenerative disorders.

The Effects of Time-Restricted Feeding on Handgrip Strength, Vigilance, and Perceived Anxiety and Depression in Older Adults: A Comparative Study Between Active and Sedentary Populations

Background and Aims

Ramadan intermittent fasting (RIF), a form of time-restricted feeding, influences various physiological and psychological functions. However, its effects on older adults remain insufficiently understood. This study examined the impact of RIF on physical and mental health parameters, comparing active and sedentary older individuals. Specifically, we assessed handgrip strength (HGS), vigilance performance, anxiety, and depression levels to determine whether regular physical activity mitigates potential adverse effects of RIF.

Methods

Fifty-eight older adults (mean age 62.93 ± 3.99 years; 50% female) participated in this study. They were classified into an active group (n = 26) and sedentary group (n = 32) based on self-reported physical activity levels. Assessments were conducted before and during RIF and included HGS measurement using a handheld dynamometer, a digital psychomotor vigilance test, and validated questionnaires (General Anxiety Disorder-7, Geriatric Depression Scale, and Physical Activity Scale for the Elderly).

Results

During RIF, both groups showed significant improvements in vigilance, anxiety, and depression scores, with more pronounced benefits in the active group. However, sedentary participants experienced a decline in HGS, whereas active individuals maintained stable muscle strength.

Conclusion

Regular physical activity during RIF appears to enhance vigilance and mental health while preventing muscle strength decline in older adults. These findings highlight the importance of maintaining an active lifestyle during RIF to support both physical and mental health in aging populations.

Manual dexterity and grip force are distinctly linked to domains of neurological soft signs in schizophrenia spectrum disorders

Motor abnormalities are highly prevalent among patients with schizophrenia spectrum disorders. Very likely, motor control processes, such as dexterity and grip force (GF), are impaired in schizophrenia. We aimed to explore associations between various motor abnormalities and motor control processes and to investigate whether specific motor abnormalities predict the performance of fine motor movements and GF. Our analyses included 198 patients with schizophrenia spectrum disorders. We applied well-established standardized motor rating scales to assess five different motor abnormalities: psychomotor slowing (PS), neurological soft signs (NSS), parkinsonism, catatonia, and dyskinesia. As a measure of manual dexterity, we used the coin rotation (CR) task, requiring patients to rotate a coin between their thumb, index, and middle finger. Maximal grip strength was measured with the GF task. Correlation analyses revealed that both CR and GF performances were associated with different motor abnormalities, most strongly with NSS (CR: tau = -0.263, p < 0.001; GF: tau = -0.208, p < 0.001). Hierarchical regression showed that NSS predicted performance on the CR and GF task better compared to PS, parkinsonism, and catatonia alone (CR: ∆R2 = 0.09, F = 22.26, p < 0.001; GF: ∆R2 = 0.02, F = 6.61, p < 0.001). When looking within the NSS domains, CR performance was predicted better by motor coordination and sequencing of motor acts, whereas GF was predicted better by sensory integration. Motor control processes are influenced by different motor abnormalities, especially NSS. Our results suggest that distinct aspects of NSS affect fine motor movements and GF. This knowledge is important for designing specific novel interventions aimed at improving specific motor control processes.

Handgrip strength is associated with functioning in patients with mental disorders: A two-center cross-sectional study

Physical and mental health are intricated, however, there is a paucity of studies investigating the association between self-reported global functioning and handgrip strength and functional capacity in people with mental disorders. This study investigated the association between functioning, handgrip strength, and functional capacity in outpatients with a range of mental disorders. This was a two-center, cross-sectional study. Functioning was assessed with the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0). Handgrip strength was assessed with a hand dynamometer, and functional exercise capacity through the 2-min walk test (2 MW T). Multiple linear regression analysis was used to identify the association between WHODAS 2.0, handgrip strength, and functional capacity, adjusted for study site, age, educational level, and severity of psychiatric symptoms. A total of 91 outpatients (mean age = 40.16 ± 13.49, 63.7% females) participated in the study. The mean functioning score was 26.77 (±8.74) out of 60 points, while the mean distance walked was 142.20 ± 34.40 m and the mean handgrip strength was 30.62 ± 11.17 kgf. The adjusted multiple linear regression analysis revealed that only handgrip strength (p = 0.008, 95%CI = -0.327 to -0.050) was associated with functioning. Thus, our results revealed that muscular strength is associated with functioning in patients with mental disorders. This study suggests the importance of incorporating physical health assessment into mental health care for a comprehensive assessment of functioning levels, which is usually restricted to mental symptoms.

Grip strength and depressive symptoms in Chinese middle-aged and older adults: the mediating effects of cognitive function

Objective

This study investigates the associations and mediating pathways between grip strength, cognitive function, and depression in middle-aged and elderly individuals in China.

Methods

Utilizing data from the 2011 China Health and Retirement Longitudinal Study (CHARLS), we employed logistic regression and mediation analysis to examine the relationships and mediating factors between grip strength, cognitive function, and depression, while adjusting for potential confounders.

Results

The study included 6,841 participants, of whom 1,734 (25.35%) exhibited symptoms of depression. Our findings indicate that weak grip strength is significantly associated with an increased risk of depression (OR: 1.57, 95% CI: 1.32-1.87) among the middle-aged and elderly population. Conversely, good cognitive function was found to be protective against depression (OR: 0.94, 95% CI: 0.93-0.95). Grip strength indirectly affected depression through cognitive function, accounting for 9.4% of the total effect (β = -0.008, 95% CI [-0.013, -0.004]). This mediating effect was 23.8% in men (β = -0.013, 95% CI [-0.020, -0.007]); and 23.2% in those aged 60 years and over (β = -0.015, 95% CI [-0.022, -0.009]).

Conclusion

This study highlights that weak grip strength increases risk of depressive symptoms, and adequate cognitive function can mitigate the association between weak grip strength and an increased risk of depression among middle-aged and elderly individuals in China. Psychological care for elder adults with weak grip strength and poor cognitive function should be strengthened.

A GWAS for grip strength in cohorts of children-Advantages of analysing young participants for this trait

Grip strength (GS) is a proxy measure for muscular strength and a predictor for bone fracture risk among other diseases. Previous genome-wide association studies (GWASs) have been conducted in large cohorts of adults focusing on scores collected for the dominant hand, therefore increasing the likelihood of confounding effects by environmental factors. Here, we perform the first GWAS meta-analyses on maximal GS with the dominant (GSD) and non-dominant (GSND) hand in two cohorts of children (ALSPAC, N = 5450; age range = 10.65-13.61; Raine Study, N = 1162, age range: 9.42-12.38 years). We identified a novel significant association for GSND (rs9546244, LINC02465, p = 3.43e-08) and replicated associations previously reported in adults including with a HOXB3 gene marker that shows an expression quantitative trait locus (eQTL) effect. Despite a much smaller sample (~3%) compared with the UK Biobank we replicated correlation analyses previously reported in this much larger adult cohort, such as a negative correlation with coronary artery disease. Although the results from the polygenic risk score (PRS) analyses did not survive multiple testing correction, we observed nominally significant associations between GS and risk of overall fracture, as previously reported, as well ADHD which will require further investigations. Finally, we observed a higher SNP-heritability (24%-41%) compared with previous studies (4%-24%) in adults. Overall, our results suggest that cohorts of children might be better suited for genetic studies of grip strength, possibly due to the shorter exposure to confounding environmental factors compared with adults.

Validity of handgrip strength for assessing cognition and psychotic symptoms in hospitalized patients with stable schizophrenia

BACKGROUND AND OBJECTIVES

A correlation between low handgrip strength (HGS), HGS asymmetry, and low cognitive performance has been demonstrated. However, it remains unclear whether low HGS is associated with psychotic symptoms and whether HGS asymmetry is associated with cognitive and psychotic symptoms in hospitalized patients with schizophrenia. This study aimed to investigate the validity of HGS as a measure for assessing cognition and psychotic symptoms in hospitalized patients with stable schizophrenia.

METHODS

A total of 235 inpatients with stable schizophrenia were recruited between August 1, 2023, and August 31, 2023. The highest HGS values from three tests on the dominant hand were used to determine low HGS (male < 28 kg, female < 18 kg), and HGS asymmetry was identified when the non-dominant HGS/dominant HGS ratio was outside 0.9-1.1. Cognition and psychotic symptoms were assessed using the Chinese Montreal Cognitive Assessment (MoCA-C) and Positive and Negative Syndrome Scale (PANSS). Generalized linear model analyses examined the relationship between HGS and scale scores.

RESULTS

Covariate-adjusted generalized linear models confirmed a strong association between low HGS alone and the MoCA-C score (OR = 0.819, 95% CI = 0.710‒0.945, p = 0.006) and PANSS score (OR = 1.113, 95% CI = 1.036‒1.239, p = 0.006). Similarly, the combination of low and asymmetric HGS was strongly associated with both MoCA-C (OR = 0.748, 95% CI = 0.653‒0.857, p<0.001) and PANSS scores (OR = 1.118, 95% CI = 1.032‒1.211, p = 0.006).

CONCLUSIONS

The results suggest that hospitalized patients with schizophrenia and low HGS, with or without asymmetry, are likely to have lower MoCA-C scores and higher PANSS scores. Screening stable schizophrenia patients with low HGS, with or without asymmetry, could be a valuable and straightforward approach to identifying those with lower cognition and severe psychotic symptoms.

Correlation of muscle strength, working memory, and activities of daily living in older adults

Objective

This study aims to investigate the relationship between muscle strength, working memory, and activities of daily living (ADL) in older adults. Additionally, it seeks to clarify the pathways and effects of working memory in mediating the relationship between muscle strength and ADL.

Methods

Using a cross-sectional study design, we recruited 245 older adults individuals from nursing homes. We collected data on grip strength, the 30-s sit-to-stand test, the N-back task, and ADL. The data were analyzed using independent sample t-tests, χ2 tests, correlation analysis, and structural equation modeling.

Results

Grip strength significantly influenced ADL (effect size = -0.175, 95% CI: -0.226 to -0.124). Grip strength also had a significant direct effect on ADL (effect size = -0.114, 95% CI: -0.161 to -0.067). The 1-back task correct rate significantly mediated the relationship between grip strength and ADL (effect size = 0.054, 95% CI: -0.084 to -0.029). The 30-s sit-to-stand test significantly impacted ADL (effect size = -0.280, 95% CI: -0.358 to -0.203). It also had a significant direct effect on ADL (effect size = -0.095, 95% CI: -0.183 to -0.007). The 1-back task correct rate significantly mediated the relationship between the 30-s sit-to-stand test and ADL (effect size = -0.166, 95% CI: -0.236 to -0.106).

Conclusion

There exists a strong correlation between muscle strength, working memory, and ADL. Increased muscle strength leads to better ADL performance and improved working memory tasks. Low cognitive load working memory tasks can mediate the relationship between muscle strength and ADL. Regular physical exercise can enhance muscle strength, slow down the decline of working memory, thereby maintaining or improving ADL in older adults.

Everyday function in schizophrenia: The impact of aerobic endurance and skeletal muscle strength

BACKGROUND

Patients with schizophrenia suffer from physical health conditions, culminating in reduced physical functioning with enormous costs for patients and society. Although aerobic endurance and skeletal muscle strength, typically reduced in this population, relate to cognition and function, no study has explored their respective contributions to performance of functional skills and everyday tasks.

METHODS

In a cross-sectional study, 48 outpatients (28/20 men/women; 35 ± 11(SD) years) with schizophrenia spectrum disorders (ICD-10; F20-25) were administered the UCSD Performance-based Skills Assessment-Brief (UPSA-B; functional skills), Specific Level of Functioning (SLOF; functional performance) and the Positive and Negative Syndrome (PANSS) scale. Peak oxygen uptake (V̇O2peak) was assessed along with leg press maximal muscle strength (1RM) and mechanical power.

RESULTS

UPSA-B performance was associated with V̇O2peak (r = 0.28,p < 0.05), accounting for 8 % (p < 0.05) of shared variance, but was unrelated to 1RM and mechanical power. The SLOF physical functioning domain was associated with V̇O2peak (r = 0.30,p < 0.05) and 1RM (r = 0.24,p < 0.05), while SLOF personal care (r = 0.27,p < 0.05) and activities (r = 0.30,p < 0.05) were related only to V̇O2peak. Hierarchical regression analyses revealed that while V̇O2peak and age combined to account for 20 % (p < 0.05) of the variance in physical functioning, the contribution of 1RM was eliminated after adjusting for age. V̇O2peak and negative symptoms combined predicted 24 % and 35 % of the variance in personal care and activities, respectively. UPSA-B scores did not add to the prediction of SLOF scores.

CONCLUSIONS

Although V̇O2peak and 1RM both relate to functional outcomes, the combination of V̇O2peak, age, and negative symptoms exert the greatest detrimental influence on functional performance beyond skills deficits.

Association between relative grip strength and depression among U.S. middle-aged and older adults: results from the NHANES database

Background

Mental health issues among middle-aged and older adults are gaining increasing attention. Recent studies have shown that relative grip strength is associated with cardiovascular diseases and various cancers, but its relationship with depression remains unclear.

Methods

This cross-sectional study included data from adults aged 50 years and older from the 2011-2014 National Health and Nutrition Examination Survey. Relative grip strength is calculated by dividing the maximum absolute grip strength of both hands by BMI. The Patient Health Questionnaire (PHQ-9) was used to evaluate the depressive outcome. Multivariate logistic regression was performed to assess the association between relative grip strength and depression.

Results

In this study, a total of 3,639 participants (≥50 years) with a mean age of 64.3 ± 9.3 years were enrolled, of whom 48.9% were male. Compared with individuals with lower relative handgrip strength in Q1 (≤1.64 kg/BMI), the adjusted OR values for relative handgrip strength and depression in Q2 (1.64-2.17 kg/BMI), Q3 (2.17-2.84 kg/BMI), and Q4 (≥2.84 kg/BMI) were 0.69 (95% CI: 0.51, 0.93, p = 0.016), 0.36 (95% CI: 0.24, 0.55, p < 0.001), and 0.32 (95% CI: 0.20, 0.51, p < 0.001), respectively. The relationship between relative grip strength and depression presented an L-shaped curve (nonlinear, p = 0.006), with an inflection point of roughly 2.98 kg/BMI. Among participants with relative grip strength < 2.98 kg/BMI, the OR of incident depression was 0.41 (95% CI: 0.30-0.55, p < 0.001).

Conclusion

Our findings indicated that relative grip strength was inversely associated with incident depression and demonstrated an L-shaped relationship among U.S. middle-aged and older adults. Relative grip strength could be the indicator for future screening of mental health.

Relative associations of behavioral and physiological risks for cardiometabolic disease with cognition in bipolar disorder during mid and later-life: findings from the UK biobank

BACKGROUND

Cardiometabolic disease risk factors are disproportionately prevalent in bipolar disorder (BD) and are associated with cognitive impairment. It is, however, unknown which health risk factors for cardiometabolic disease are relevant to cognition in BD. This study aimed to identify the cardiometabolic disease risk factors that are the most important correlates of cognitive impairment in BD; and to examine whether the nature of the relationships vary between mid and later life.

METHODS

Data from the UK Biobank were available for 966 participants with BD, aged between 40 and 69 years. Individual cardiometabolic disease risk factors were initially regressed onto a global cognition score in separate models for the following risk factor domains; (1) health risk behaviors (physical activity, sedentary behavior, smoking, and sleep) and (2) physiological risk factors, stratified into (2a) anthropometric and clinical risk (handgrip strength, body composition, and blood pressure), and (2b) cardiometabolic disease risk biomarkers (CRP, lipid profile, and HbA1c). A final combined multivariate regression model for global cognition was then fitted, including only the predictor variables that were significantly associated with cognition in the previous models.

RESULTS

In the final combined model, lower mentally active and higher passive sedentary behavior, higher levels of physical activity, inadequate sleep duration, higher systolic and lower diastolic blood pressure, and lower handgrip strength were associated with worse global cognition.

CONCLUSIONS

Health risk behaviors, as well as blood pressure and muscular strength, are associated with cognitive function in BD, whereas other traditional physiological cardiometabolic disease risk factors are not.

Changes in cognitive function after a 12-week POWER rehabilitation in older adults with schizophrenia and frailty

BACKGROUND

The effectiveness of isolated resistance training (RT) on cognitive function among older adults with schizophrenia is insufficiently investigated. This study investigated the effectiveness of 12-weeks POWER rehabilitation, a novel RT regimen, on cognitive function among older patients with schizophrenia and frailty.

METHODS

Thirty-two older adults with schizophrenia and frailty were enrolled and randomized to receive either a 12-week, twice weekly POWER rehabilitation, or without add-on training. Cognitive functioning was assessed using mini-mental state examination (MMSE), digit symbol substitution test, color trail task (CTT), and digit span task (DST). Physical performance was assessed by walking speed and hand grip strength. The generalized estimating equations was used to compare pre- and post-training outcome measure between groups.

RESULTS

Between-group analysis revealed significant improvement in CTT1 and hand grip strength in the intervention group compared to the controls. Subgroup analyses showed CTT1 performance significantly improved after 12 weeks of POWER rehabilitation in the intervention group (time, p < .001), independent of age, educational level, global cognition, depressive symptoms, and psychotropic medication use. Increased hand grip strength was significantly associated with improved performance in MMSE, CTT1, and DST forward at study endpoint.

CONCLUSION

A 12-week POWER rehabilitation for older patients with schizophrenia and frailty is safe and feasible, and may benefit physical and some domains of cognitive functioning.

Exploring the Association between Elevated Anxiety Symptoms and Low Skeletal Muscle Mass among Asymptomatic Adults: A Population-Based Study in Republic of Korea

Individuals with mental health problems are at higher risk of musculoskeletal diseases. However, the association between low muscle mass (LMM) and anxiety symptoms remains uninvestigated. This cross-sectional study enrolled 174,262 adults (73,833 women, 100,429 men), aged 18 to 89, who completed the anxiety scale and body composition analyses. Using bio-electrical impedance analysis, skeletal muscle mass index (SMI) was calculated based on appendicular skeletal muscle mass (ASM) (kg)/height (m2). LMM was defined as SMI < 7.0 kg/m2 in men and <5.4 kg/m2 in women. Anxiety symptoms were screened using the Clinical Useful Anxiety Outcome Scale (CUXOS) with cut-off scores of 20, 30, and 40. Multivariable logistic regression analyses were performed. LMM prevalence was 20.17% in women, 3.86% in men (p < 0.001). The prevalence of anxiety symptoms in LMM group decreased from mild (CUXOS > 20: women, 32.74%, men, 21.17%) to moderate (CUXOS > 30: 13.34%, 7.32%), to severe anxiety symptoms (CUXOS > 40: 4.00%, 1.73%). In multivariable-adjusted models, LMM was associated with mild (aOR (95% confidence interval)), women, 1.13 (1.08-1.17); men, 1.17 (1.08-1.27)), moderate (1.17 (1.11-1.24); 1.35 (1.19-1.53) and severe anxiety symptoms (1.18 (1.07-1.3), 1.36 (1.06-1.74)), demonstrating an increased risk of ORs with escalating anxiety severity. LMM was independently associated with a higher prevalence of anxiety symptoms.

Examining factors contributing to the socioeconomic inequalities in handgrip strength among older adults in India: a decomposition analysis

The purpose of this study was to examine (a) the socioeconomic status (SES)-related inequalities associated with handgrip strength (HGS); and (b) the extent to which several demographic, health, and behavioral factors contributed to such SES disparities in HGS among older adults in India. Data were drawn from the 2017-2018 wave 1 of the Longitudinal Ageing Study of India (LASI). The study sample included 27,707 older adults (13,199 men and 14,508 women) aged 60 years and older. HGS was assessed using a handheld Smedley's Hand Dynamometer with a cut-off of 19.5 kg for men and 12.5 kg for women. Bivariate analysis showed the weighted percentage distribution of weak HGS across respondent characteristics. Multivariate logistic regression assessed factors linked to weak HGS. The concentration curve and index (CCI) was used to determine the inequalities in the prevalence of weak HGS by wealth index scores. Wagstaff's decomposition approach was used to test the contribution of each explanatory variable to weak HGS. Around 9% of older adults in this study reported a weak HGS. It was significantly higher among those aged 80 or older (19.21%) and males (15.55%). Weak HGS was concentrated among older adults from poor SES (CCI: 0.05, p < 0.001). A higher percentage of wealth-based inequality in weak HGS was explained by being underweight (38.83%), belonging to the richest wealth quintile (27.95%), and having a higher subjective social status (32.20%). Moreover, about 23.29% of the inequality in weak HGS was explained by Western region and 22.54% by female gender. Additionally, having a secondary level of education explained a higher percentage (22.09%) of inequality, followed by current working status (- 20.68%). Rural residence (13.08%), limitations in instrumental activities of daily living (IADL) (12.21%), and engagement in yoga-related activities (11.55%) explained a higher percentage of wealth-based inequalities. The findings provide evidence of significant SES-related inequalities in HGS and the contribution of various demographic, health, and behavioral factors to such inequality. As such, public health policies and programs focusing on reducing the burden of disability must consider the contribution of social and economic equity to the preservation of muscle strength among older adults.

Detrimental effects of effortful physical exertion on a working memory dual-task in older adults

Action and cognition often interact in everyday life and are both sensitive to the effects of aging. The present study tested the effects of a simple physical action, effortful handgrip exertion, on working memory (WM) and inhibitory control in younger and older adults. Using a novel dual-task paradigm, participants engaged in a WM task with 0 or 5-distractors under concurrent physical exertion (5% vs. 30% individual maximum voluntary contraction). Effortful physical exertion, although failing to effect WM accuracy in the distractor absent condition for both age groups, reduced WM accuracy for the older, but not young adults, in the distractor-present condition. Similarly, older adults experienced greater distractor interference in the distractor-present condition under high physical exertion, indexed by slower reaction time (RT), confirmed by hierarchical Bayesian modeling of RT distributions. Our finding that a simple but effortful physical task results in impaired cognitive control may be empirically important for understanding everyday functions of older adults. For example, the ability to ignore task-irrelevant items declines with age and this decline is greater when simultaneously performing a physical task, which is a frequent occurrence in daily life. The negative interactions between cognitive and motor tasks may further impair daily functions, beyond the negative consequences of reduced inhibitory control and physical abilities in older adults. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Association between handgrip strength asymmetry and cognitive function across ethnicity in rural China: a cross-sectional study

Background

Recently, the association between handgrip strength (HGS) asymmetry and cognition has been revealed, but evidences are still scarce. Particularly, the association between asymmetric HGS and cognitive performance in various cognitive domains is unclear and whether this association is stable across ethnic groups is unknown.

Method

The population was from a longitudinal study in rural areas of Fuxin, Liaoning, China. The Chinese version of Montreal Cognitive Assessment-Basic (MOCA-BC) was used to evaluate the cognitive function. The HGS ratio was calculated as maximal non-dominant HGS divided by maximal dominant HGS. HGS ratio <0.9 or >1.1 was classified as asymmetric dominant/non-dominant HGS, respectively. Generalized linear models were used to analyze the relationship between asymmetric HGS and cognitive function adjusted for HGS, handedness, wave, age, sex, education, ethnicity, smoking, drinking, physical labor level, BMI, hypertension, diabetes and dyslipidemia.

Result

A total of 2,969 participants ≥50 years were included in this study. Adjusted for HGS and other confunding variables, there was an inverted U-shaped association between HGS ratio and MoCA-BC scores (P _non-linear = 0.004). The association between HGS ratio and MoCA-BC scores was inconsistent among ethnic groups (P _interaction = 0.048). In Han, only asymmetric non-dominant HGS was associated with lower cognitive scores [β = -0.67, 95% confidence interval (CI): -1.26 ∼-0.08, P = 0.027]; in Mongolians, asymmetric dominant HGS(β = -0.60, 95% CI: -1.35 ∼ 0.15, P = 0.115) and asymmetric non-dominant HGS (β = -0.56, 95% CI: -1.42 ∼ 0.31, P = 0.206) were all associated with lower cognitive scores, although no statistical significance was found. Asymmetric non-dominant HGS and lower HGS, but not asymmetric dominant HGS were all independently associated with impairment of Delayed Recall (OR = 1.35, 95% CI: 1.05 ∼ 1.74; OR _{per 5 kg decrease} = 1.10, 95% CI: 1.01 ∼ 1.21) and Fluency (OR = 1.43, 95% CI: 1.15 ∼ 1.78; OR _{per 5 kg decrease} = 1.10, 95% CI: 1.02 ∼ 1.19). Both asymmetric dominant HGS (OR = 1.34, 95% CI: 1.07 ∼ 1.67) and lower HGS (OR _{per 5 kg decrease} = 1.21, 95% CI: 1.10 ∼ 1.32) were associated with impairment of visuoperception.

Conclusion

HGS and HGS asymmetry were all independently related to lower global cognitive performance. The association between HGS asymmetry and cognitive function varies among ethnic groups.

Mutually exclusive disorder-dependent hearing discomfort in first-episode psychosis and panic disorder: two experiments using the same auditory stimulus set and two similar musical sequences

We investigated the level of hearing tolerance in patients with first-episode psychosis (FEP) and panic disorder (PD) as compared to two different groups of healthy controls (HC, HC2), one for each experiment, because we used two distinct psychophysical paradigms. We evaluated auditory discomfort of 28 volunteers (14 with FEP and 14 HC) in the first study and of 42 volunteers (21 with PD and 21 HC2) in the second study. We presented 20 sounds: 16 pure-tone frequency sweeps (specially designed for use with FEP) and 11 s or 13 s musical sequences from the very beginning of the music "Play the Game" (PLAY) from Queen and its reverses. The first procedure used a Likert-like 0-10 scale ranging from "nothing bad" to "too bad" where volunteers made vertical marks along a horizontal line according to their discomfort. The second procedure involved subjective magnitude estimation online due to the SARS-COV-19 pandemic. Sounds were placed online and played by PD and HC2 volunteers themselves after having listened to the standard (the first 8 s from RADIO, "Radio Ga Ga" by Queen). Then, PD and HC2 volunteers were asked to assign values equal to, or multiples of 10 that felt like, or proportional to, their hearing "discomfort" in comparison with Sound 00 (RADIO). Our findings showed that FEP volunteers assign more discomfort to the 16 specially designed frequency sweep stimuli that appear not to affect HC, HC2, and PD. On the other hand, musical sequences from PLAY caused strong discomfort to PD in the reverse mode, but did not seem to affect HC, HC2, and FEP. Further experiments using the exact same paradigm with FEP and PD are needed to explore these findings.

Association between grip strength and cognitive impairment in older American adults

BACKGROUND AND AIMS

Exponential population aging has led to an increased prevalence of cognitive impairment worldwide. Hand grip strength, which may be associated with physical activity, could be a useful predictor of cognitive impairment. However, few studies have reported the association, if any, between hand grip strength and cognitive function.

METHODS

We used data obtained from the National Health and Nutrition Examination Survey between 2011-2012 and 2013-2014 to investigate the association between hand grip strength and cognitive impairment. Cognitive impairment was assessed using the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), animal fluency (AF), and digit symbol substitution test (DSST) scores. Cutoff values of CERAD < 5, AF < 14, and DSST < 34 were used to define cognitive impairment. In this cross-sectional study, we used odds ratios to determine the potential usefulness of hand grip strength for the prediction of cognitive impairment.

RESULTS

This study included 2,623 participants aged ≥60 years. The DSST results showed that hand grip strength was associated with a low risk of cognitive impairment and that subgroup analysis showed that male sex, 60-69 years of age, and the Non-Hispanic (NH)-White, NH Black, and Asian were associated with a significantly low risk of cognitive impairment. The CERAD test results showed that 70-79 years of age and the NH White were significantly associated with a low risk of cognitive impairment. By following full adjustment, we did not observe statistically significant differences between hand grip strength and cognitive impairment based on the CERAD test. The AF test results showed that >80 years of age, female sex, and the NH White were associated with a significantly low risk of cognitive impairment. The most important finding is that a linear association lies between grip strength and cognitive impairment, as well as a sex-based linear association. Machine learning of the XGBoost model suggests that grip strength is one of the top two most important negative predictor variables.

CONCLUSION

We observed an inverse relationship between hand grip strength and cognitive impairment, which might suggest a shared underlying mechanism that needs to be further investigated using a large-scale prospective clinical trial to validate our findings.

Associations between grip strength, brain structure, and mental health in > 40,000 participants from the UK Biobank

BACKGROUND

Grip strength is a widely used and well-validated measure of overall health that is increasingly understood to index risk for psychiatric illness and neurodegeneration in older adults. However, existing work has not examined how grip strength relates to a comprehensive set of mental health outcomes, which can detect early signs of cognitive decline. Furthermore, whether brain structure mediates associations between grip strength and cognition remains unknown.

METHODS

Based on cross-sectional and longitudinal data from over 40,000 participants in the UK Biobank, this study investigated the behavioral and neural correlates of handgrip strength using a linear mixed effect model and mediation analysis.

RESULTS

In cross-sectional analysis, we found that greater grip strength was associated with better cognitive functioning, higher life satisfaction, greater subjective well-being, and reduced depression and anxiety symptoms while controlling for numerous demographic, anthropometric, and socioeconomic confounders. Further, grip strength of females showed stronger associations with most behavioral outcomes than males. In longitudinal analysis, baseline grip strength was related to cognitive performance at ~9 years follow-up, while the reverse effect was much weaker. Further, baseline neuroticism, health, and financial satisfaction were longitudinally associated with subsequent grip strength. The results revealed widespread associations between stronger grip strength and increased grey matter volume, especially in subcortical regions and temporal cortices. Moreover, grey matter volume of these regions also correlated with better mental health and considerably mediated their relationship with grip strength.

CONCLUSIONS

Overall, using the largest population-scale neuroimaging dataset currently available, our findings provide the most well-powered characterization of interplay between grip strength, mental health, and brain structure, which may facilitate the discovery of possible interventions to mitigate cognitive decline during aging.

Association Between Grip Strength and Cognitive Function in US Older Adults of NHANES 2011–2014

Background: The relationship between grip strength and cognitive function remains no consensus in the older adults. Objective: To investigate the association of grip strength with cognitive function and cognitive performance in different domains. Methods: Participants of the present cross-sectional study were from the National Health and Nutrition Examination Survey 2011-2014. Grip strength was measured by grip dynamometer, and combined handgrip strength was the sum of the largest reading from each hand. Four cognitive domains (immediate and delayed memory, language, and attention) were assessed by a set of neuropsychological tests. The subjective cognitive decline was determined via self-report. Results: Among 2,618 participants, combined grip strength was positively associated with scores on global cognitive function and each cognitive domain after controlling for demographic characteristics, lifestyle factors, and history of disease. In addition, compared to those with grip strength <  46.7 kg, participants with grip strength≥75.3 kg had odds ratios of 0.36 (95% CI: 0.21 to 0.63) for poor global cognitive function, 0.66 (95% CI: 0.38 to 1.13) for poor immediate memory, 0.53 (95% CI: 0.30 to 0.93) for poor delayed memory, 0.48 (95% CI: 0.27 to 0.86) for poor language function, 0.20 (95% CI: 0.11 to 0.35) for poor attention, and 0.36 (95% CI: 0.18 to 0.73) for subjective cognitive decline in fully adjusted model. Conclusion: Older adults with higher grip strength were significantly associated with better performance on cognition function included global and various domains such as memory, language, attention, and subjective cognitive decline.

Associations of handgrip strength with morbidity and all-cause mortality of cardiometabolic multimorbidity

BACKGROUND

Cardiometabolic multimorbidity (CM) is an increasing public health and clinical concern. However, predictors for the development and prognosis of CM are poorly understood. The aims of this study were to investigate the relation between handgrip strength (HGS) and the risk of CM and to examine the association of HGS with all-cause mortality risk among patients with CM.

METHODS

This prospective cohort study involved 493,774 participants from the UK Biobank. CM was defined as the simultaneous occurrence of two or more of the following conditions: type 2 diabetes, stroke, and coronary heart disease (CHD). Cox proportional hazards models were performed to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs).

RESULTS

During a median follow-up of 12.1 years, 4701 incident CM cases were documented among participants with none cardiometabolic disease at baseline. Compared with the fourth quartile (Q4), the multivariable adjusted HR (95% CI) value of Q1 of HGS for developing CM was 1.46 (1.34-1.60). In participants with one cardiometabolic disease at baseline, participants in Q1 of HGS also possessed higher risk of CM than those in Q4, with HRs (95% CIs) being 1.35 (1.23-1.49) in patients with type 2 diabetes, 1.23 (1.04-1.46) in patients with stroke, and 1.23 (1.11-1.36) in patients with CHD. For participants with CM at recruitment, HGS was also associated with the risk of all-cause mortality (Q1 vs. Q4 HR: 1.57, 95% CI: 1.36-1.80).

CONCLUSIONS

Our study provided novel evidence that HGS could be an independent predictor of morbidity and all-cause mortality of CM.

Associations Between Handgrip Strength and Dementia Risk, Cognition, and Neuroimaging Outcomes in the UK Biobank Cohort Study

IMPORTANCE

The associations between muscle strength and cognitive outcomes have sparked interest in interventions that increase muscle strength for prevention of dementia, but the associations between muscle strength and cognitive aging are unclear, particularly among middle-aged adults.

OBJECTIVE

To evaluate the association between handgrip strength (HGS) and dementia, reduced cognition, and poorer neuroimaging outcomes in a UK population of middle-aged adults.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study evaluated UK Biobank participants aged 39 to 73 years enrolled from 2006 to 2010 with measured HGS and prospectively followed up for dementia diagnosis. Data were analyzed from October 2021 to April 2022.

EXPOSURES

HGS assessed in both hands via dynamometer.

MAIN OUTCOMES AND MEASURES

Outcomes included cognitive test scores (fluid intelligence and prospective memory), brain magnetic resonance imaging measures (total brain volume, white matter hyperintensity, and hippocampal volume), and incident dementia (all-cause, vascular, and Alzheimer disease [AD] from primary care, hospital, or death records) over a median (IQR) of 11.7 (11.0-12.4) years of follow-up. Mixed-effects linear and logistic regressions and Cox proportional-hazard models were used to estimate associations, stratified by gender and adjusted for covariates. Estimates are presented per 5-kg decrement in HGS. To evaluate reverse causation, we assessed whether a polygenic risk score for AD is associated with HGS.

RESULTS

A subsample of 190 406 adult participants in the UK Biobank (mean [SD] age, 56.5 [8.1] years; 102 735 women [54%]) were evaluated. A 5-kg decrement in HGS was associated with lower fluid intelligence scores in men (β, -0.007; 95% CI, -0.010 to -0.003) and women (β, -0.04; 95% CI, -0.05 to -0.04. A 5-kg decrement in HGS was associated with worse odds of correctly responding to a prospective memory task for men (odds ratio, 0.91; 95% CI, 0.90 to 0.92) and women (odds ratio, 0.88; 95% CI, 0.87 to 0.90). A 5-kg decrement in HGS was associated with greater white matter hyperintensity volume in men (β, 92.22; 95% CI, 31.09 to 153.35) and women (β, 83.56; 95% CI, 13.54 to 153.58). A 5-kg decrement in HGS was associated with incident dementia for men (hazard ratio, 1.20; 95% CI, 1.12 to 1.28) and women (hazard ratio, 1.12; 95% CI, 1.00 to 1.26). The AD genetic risk score was not significantly associated with HGS.

CONCLUSIONS AND RELEVANCE

These findings suggest that HGS is associated with measures of neurocognitive brain health among men and women and they add to a growing body of research indicating that interventions designed to increase muscle strength, particularly among middle-aged adults, may hold promise for the maintenance of neurocognitive brain health.

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.

Combined effects of handgrip strength and sensory impairment on the prevalence of cognitive impairment among older adults in Korea

Older adults commonly experience concurrent lower handgrip strength and sensory impairment. However, previous studies have analyzed the individual effects of either handgrip strength or sensory impairment on cognitive impairment. To address this gap, this study investigated the combined effects of handgrip strength and sensory impairment on cognitive impairment among older adults. In total, 2930 participants aged 65 and older were analyzed using 2014–2018 data from the Korean Longitudinal Study of Aging. Participants underwent assessments of handgrip strength (grip dynamometer), sensory impairment (self-reported responses), and cognitive impairment (Korean version of the Mini-Mental State Examination). Low handgrip strength, compared to normal handgrip strength, was associated with cognitive impairment. In participants with low handgrip strength, vision and hearing impairment were associated with cognitive impairment (odds ratio [OR] 1.36, 95% confidence interval [CI] 1.06–1.75; OR 2.58, 95% CI 1.77–3.78, respectively) compared to those with normal handgrip strength. Participants with low handgrip strength and dual sensory impairment had the highest OR for cognitive impairment (OR 3.73, 95% CI 2.65–5.25). Due to the strong association of low handgrip strength and dual sensory impairment with cognitive impairment, people living with low handgrip strength and dual sensory impairment should be classified as a high-risk group for cognitive impairment and should be prioritized for interventions.

Cognitive impairment and World Trade Centre-related exposures

On 11 September 2001 the World Trade Center (WTC) in New York was attacked by terrorists, causing the collapse of multiple buildings including the iconic 110-story 'Twin Towers'. Thousands of people died that day from the collapse of the buildings, fires, falling from the buildings, falling debris, or other related accidents. Survivors of the attacks, those who worked in search and rescue during and after the buildings collapsed, and those working in recovery and clean-up operations were exposed to severe psychological stressors. Concurrently, these 'WTC-affected' individuals breathed and ingested a mixture of organic and particulate neurotoxins and pro-inflammogens generated as a result of the attack and building collapse. Twenty years later, researchers have documented neurocognitive and motor dysfunctions that resemble the typical features of neurodegenerative disease in some WTC responders at midlife. Cortical atrophy, which usually manifests later in life, has also been observed in this population. Evidence indicates that neurocognitive symptoms and corresponding brain atrophy are associated with both physical exposures at the WTC and chronic post-traumatic stress disorder, including regularly re-experiencing traumatic memories of the events while awake or during sleep. Despite these findings, little is understood about the long-term effects of these physical and mental exposures on the brain health of WTC-affected individuals, and the potential for neurocognitive disorders. Here, we review the existing evidence concerning neurological outcomes in WTC-affected individuals, with the aim of contextualizing this research for policymakers, researchers and clinicians and educating WTC-affected individuals and their friends and families. We conclude by providing a rationale and recommendations for monitoring the neurological health of WTC-affected individuals.

A Link between Handgrip Strength and Executive Functioning: A Cross-Sectional Study in Older Adults with Mild Cognitive Impairment and Healthy Controls

Older adults with amnestic mild cognitive impairment (aMCI) who in addition to their memory deficits also suffer from frontal-executive dysfunctions have a higher risk of developing dementia later in their lives than older adults with aMCI without executive deficits and older adults with non-amnestic MCI (naMCI). Handgrip strength (HGS) is also correlated with the risk of cognitive decline in the elderly. Hence, the current study aimed to investigate the associations between HGS and executive functioning in individuals with aMCI, naMCI and healthy controls. Older, right-handed adults with amnestic MCI (aMCI), non-amnestic MCI (naMCI), and healthy controls (HC) conducted a handgrip strength measurement via a handheld dynamometer. Executive functions were assessed with the Trail Making Test (TMT A&B). Normalized handgrip strength (nHGS, normalized to Body Mass Index (BMI)) was calculated and its associations with executive functions (operationalized through z-scores of TMT B/A ratio) were investigated through partial correlation analyses (i.e., accounting for age, sex, and severity of depressive symptoms). A positive and low-to-moderate correlation between right nHGS (rp (22) = 0.364; p = 0.063) and left nHGS (rp (22) = 0.420; p = 0.037) and executive functioning in older adults with aMCI but not in naMCI or HC was observed. Our results suggest that higher levels of nHGS are linked to better executive functioning in aMCI but not naMCI and HC. This relationship is perhaps driven by alterations in the integrity of the hippocampal-prefrontal network occurring in older adults with aMCI. Further research is needed to provide empirical evidence for this assumption.

Effect of Exercise on Secondary Sarcopenia: A Comprehensive Literature Review

Simple Summary

Sarcopenia is an inevitable component of aging. It is officially recognized as a muscle disease with an ICD-10-MC diagnosis code that can be used to bill for care in some countries. Sarcopenia can be classified into primary or age-related sarcopenia and secondary sarcopenia. The condition is referred to as secondary sarcopenia when any other comorbidities are present in conjunction with aging. Secondary sarcopenia is more prevalent than primary sarcopenia and requires special attention. Exercise interventions may help in our understanding and prevention of sarcopenia with a specific morbidity Glomerular filtration rate that exercise improves muscle mass, quality or physical function in elderly subjects with cancer, type 2 diabetes, kidney diseases and lung diseases. In this review, we summarize recent research that has studied the impact of exercise on patients with secondary sarcopenia, specifically those with one comorbid condition. We did not discover any exercise intervention specifically for subjects with secondary sarcopenia (with one comorbidity). Even though there is a strong argument for using exercise to improve muscle mass, quality or physical function in subjects with cancer, type 2 diabetes, kidney diseases, lung diseases and many more, very few studies have reported baseline sarcopenia assessments. Based on the trials summarized in this review, we may propose but not conclude that resistance, aerobic, balance training or even walking can be useful in subjects with secondary sarcopenia with only one comorbidity due to the limited number of trials. This review is significant because it reveals the need for broad-ranging research initiatives involving secondary sarcopenic patients and highlights a large secondary sarcopenia research gap.

Abstract

Background: Sarcopenia has been recognized as an inevitable part of aging. However, its severity and the age at which it begins cannot be predicted by age alone. The condition can be categorized into primary or age-related sarcopenia and secondary sarcopenia. Sarcopenia is diagnosed as primary when there are no other specific causes. However, secondary sarcopenia occurs if other factors, including malignancy or organ failure, are evident in addition to aging. The prevalence of secondary sarcopenia is far greater than that of primary sarcopenia and requires special attention. To date, nutrition and exercise have proven to be the best methods to combat this disease. The impact of exercise on subjects suffering from sarcopenia with a specific morbidity is worthy of examination for understanding and prevention. The purpose of this review, therefore, is to summarize recent research that has investigated the impact of exercise in patients with secondary sarcopenia, specifically with one comorbidity. Methods: Pubmed, Web of Science, Embase and Medline databases were searched comprehensively with no date limit for randomized controlled trials. The literature was specifically searched for clinical trials in which subjects were sarcopenic with only one comorbidity participating in an exercise intervention. The most visible comorbidities identified and used in the search were lung disease, kidney disease, heart disease, type 2 diabetes, cancer, neurological diseases, osteoporosis and arthritis. Results: A total of 1752 studies were identified that matched the keywords. After removing duplicates, there were 1317 articles remaining. We extracted 98 articles for full screening. Finally, we included 21 relevant papers that were used in this review. Conclusion: Despite a strong rationale for using exercise to improve muscle mass, quality or physical function in subjects with cancer, type 2 diabetes, kidney disease, lung disease and many more, baseline sarcopenia evaluation has been reported in very few trials. The limited number of studies does not allow us to conclude that exercise can improve sarcopenia in patients with other comorbidities. This review highlights the necessity for wide-ranging research initiatives involving secondary sarcopenic patients.

Association between physical fitness, body mass index and intelligence quotient in individuals with intellectual disabilities

BACKGROUND

Physical exercise seems to improve cognitive abilities at different physiological levels. Numerous studies have examined the relationship between physical fitness (PF), physical activity and cognition among populations without intellectual disabilities (ID), but very few have addressed this question with respect to people with ID. This study aimed to determine the correlation between intelligence quotient (IQ) and factors related to PF in healthy adults with ID.

METHODS

A multicentre cross-sectional study was conducted in 91 individuals with ID. All participants were assessed with the K-BIT tests and the following test items from the SAMU DIS-FIT Battery: body mass index, handgrip strength (HGS), leg strength, dynamic balance and physical endurance.

RESULTS

Significant differences between men and women were tested by multiple regression. IQ was found to be statistically related to HGS and leg strength, with a medium effect size. Statistical relationships were also found between sex and physical endurance, with a medium effect size, and HGS, with a large effect size.

CONCLUSIONS

The study results highlight relationships between the variables of muscular strength and the participants' IQ. Further studies with experimental designs are needed to enhance the understanding of the relationships between PF and cognition in persons with ID.

Grip training improves handgrip strength, cognition, and brain white matter in minor acute ischemic stroke patients

OBJECTIVE

A large proportion of stroke patients experience cognitive impairment. Previous studies found that handgrip training can improve cognitive dysfunction after stroke through an unknown mechanism. In this study, we aimed to examine the influence of handgrip training on the cognition of patients with acute mild ischemic stroke and explore the mechanism using an advanced post-processing method for magnetic resonance imaging.

METHODS

Seventy-six patients with acute mild ischemic stroke were recruited for this study and randomly divided into a grip training group (n = 37) and a control group (n = 39). Both groups of patients also received standardized treatment for stroke in the acute phase and for secondary prevention, as well as conventional physical therapy after stroke. Grip strength, global cognitive function, and the local and global efficiencies of white matter networks derived from diffusion tensor images were measured before and after the 12-week training period.

RESULTS

In the within-group comparisons, grip training significantly improved the grip strength (3.52 [3.09-3.96], p = 0.02), Montreal Cognitive Assessment (MoCA) (2.27 [1.68-2.86], p = 0.05), and local, but not global, efficiency of the brain white matter network (0.03 [0.02-0.03], p = 0.02) in the experimental group. In contrast, these parameters were not statistically different over the same period in the control group. In the between-groups comparisons, the improvement of grip strength (2.71 [2.20-3.21], p = 0.01), MoCA (1.17 [0.39-1.95], p = 0.05), and local efficiency (0.02 [0.01-0.03], p = 0.01) showed statistically significant differences after the intervention, but not the absolute value of them, neither at the base line nor after the intervention.

CONCLUSIONS

Our results indicate that grip training can improve cognitive function by increasing the local efficiency of brain white matter connectivity. This suggests that white matter remodeling is a potential physiological mechanism connecting grip training and cognition improvement.

Handgrip strength as a moderator of the influence of age on olfactory impairment in US adult population ≥ 40 years of age

The aim of this study was to determine whether handgrip strength attenuates the negative relationship between age and olfactory function in a representative US population sample 40 years old and over. A cross-sectional study was performed with 2861 adults from the US National Health and Nutrition Examination Survey NHANES (2013–2014). An 8-item odor identification test was applied to determine olfactory function. Muscle strength was determined through a handgrip dynamometer (defined as the sum of the largest handgrip strength reading from right and left hands). Moderation analysis was performed to test whether the association between age and olfactory impairment was moderated by handgrip strength. Moderation analysis highlighted two regions of significance: the first region was found at < 56.6 kg, indicating that the adverse influence of age on olfactory function may be greater for the participants in this area; the second region was found at ≥ 56.6 kg, indicating that the negative impact of age on olfactory function disappeared for adults who were above this estimate point. In conclusion, handgrip strength, a general indicator of muscle strength, moderates the relationship between age and olfactory ability in a US adult population aged 40 years and older. Our findings are clinically relevant, since they emphasize the importance of muscular fitness in adulthood and old age by diminishing the deleterious effect of aging on olfactory performance.

Identification of novel and rare variants associated with handgrip strength using whole genome sequence data from the NHLBI Trans-Omics in Precision Medicine (TOPMed) Program

Handgrip strength is a widely used measure of muscle strength and a predictor of a range of morbidities including cardiovascular diseases and all-cause mortality. Previous genome-wide association studies of handgrip strength have focused on common variants primarily in persons of European descent. We aimed to identify rare and ancestry-specific genetic variants associated with handgrip strength by conducting whole-genome sequence association analyses using 13,552 participants from six studies representing diverse population groups from the Trans-Omics in Precision Medicine (TOPMed) Program. By leveraging multiple handgrip strength measures performed in study participants over time, we increased our effective sample size by 7-12%. Single-variant analyses identified ten handgrip strength loci among African-Americans: four rare variants, five low-frequency variants, and one common variant. One significant and four suggestive genes were identified associated with handgrip strength when aggregating rare and functional variants; all associations were ancestry-specific. We additionally leveraged the different ancestries available in the UK Biobank to further explore the ancestry-specific association signals from the single-variant association analyses. In conclusion, our study identified 11 new loci associated with handgrip strength with rare and/or ancestry-specific genetic variations, highlighting the added value of whole-genome sequencing in diverse samples. Several of the associations identified using single-variant or aggregate analyses lie in genes with a function relevant to the brain or muscle or were reported to be associated with muscle or age-related traits. Further studies in samples with sequence data and diverse ancestries are needed to confirm these findings.

Population-based body-brain mapping links brain morphology with anthropometrics and body composition

Understanding complex body-brain processes and the interplay between adipose tissue and brain health is important for understanding comorbidity between psychiatric and cardiometabolic disorders. We investigated associations between brain structure and anthropometric and body composition measures using brain magnetic resonance imaging (MRI; n = 24,728) and body MRI (n = 4973) of generally healthy participants in the UK Biobank. We derived regional and global measures of brain morphometry using FreeSurfer and tested their association with (i) anthropometric measures, and (ii) adipose and muscle tissue measured from body MRI. We identified several significant associations with small effect sizes. Anthropometric measures showed negative, nonlinear, associations with cerebellar/cortical gray matter, and brain stem structures, and positive associations with ventricular volumes. Subcortical structures exhibited mixed effect directionality, with strongest positive association for accumbens. Adipose tissue measures, including liver fat and muscle fat infiltration, were negatively associated with cortical/cerebellum structures, while total thigh muscle volume was positively associated with brain stem and accumbens. Regional investigations of cortical area, thickness, and volume indicated widespread and largely negative associations with anthropometric and adipose tissue measures, with an opposite pattern for thigh muscle volume. Self-reported diabetes, hypertension, or hypercholesterolemia were associated with brain structure. The findings provide new insight into physiological body-brain associations suggestive of shared mechanisms between cardiometabolic risk factors and brain health. Whereas the causality needs to be determined, the observed patterns of body-brain relationships provide a foundation for understanding the underlying mechanisms linking psychiatric disorders with obesity and cardiovascular disease, with potential for the development of new prevention strategies.

Physical activity as an intervention in severe mental illness

Physical activity is a modifiable risk factor for several physical and mental health conditions. It is well established that people with severe mental illness have increased risk of physical health complications, particularly cardiovascular disease. They are also more likely to be physically inactive, contributing to the elevated cardiovascular and metabolic risks, which are further compounded by antipsychotic medication use. Interventions involving physical activity are a relatively low risk and accessible way of reducing physical health problems and weight in people with severe mental illness. They also have wider benefits for mental health symptoms and quality of life. However, many barriers still exist to the widespread implementation of physical activity interventions in the treatment of severe mental illness. A more concerted effort is needed to facilitate their translation into routine practice and to increase adherence to activity interventions.

Cortical hemodynamics as a function of handgrip strength and cognitive performance: a cross-sectional fNIRS study in younger adults

BACKGROUND

There is growing evidence for a positive correlation between measures of muscular strength and cognitive abilities. However, the neurophysiological correlates of this relationship are not well understood so far. The aim of this study was to investigate cortical hemodynamics [i.e., changes in concentrations of oxygenated (oxyHb) and deoxygenated hemoglobin (deoxyHb)] as a possible link between measures of muscular strength and cognitive performance.

METHODS

In a cohort of younger adults (n = 39, 18-30 years), we assessed (i) handgrip strength by a handhold dynamometer, (ii) short-term working memory performance by using error rates and reaction times in the Sternberg task, and (iii) cortical hemodynamics of the prefrontal cortex (PFC) via functional near-infrared spectroscopy (fNIRS).

RESULTS

We observed low to moderate negative correlations (rp =  ~ - 0.38 to - 0.51; p < 0.05) between reaction time and levels of oxyHb in specific parts of the PFC. Furthermore, we noticed low to moderate positive correlations (rp =  ~ 0.34 to 0.45; p < 0.05) between reaction times and levels of deoxyHb in distinct parts of the PFC. Additionally, higher levels of oxyHb (rp (35) = 0.401; p = 0.014) and lower levels of deoxyHb (rp (34) = - 0.338; p = 0.043) in specific parts of the PFC were linked to higher percentage of correct answers. We also found low to moderate correlations (p < 0.05) between measures of handgrip strength and levels of oxyHb (rp =  ~ 0.35; p < 0.05) and levels of deoxyHb (rp =  ~ - 0.25 to - 0.49; p < 0.05) in specific parts of the PFC. However, there was neither a correlation between cognitive performance and handgrip strength nor did cortical hemodynamics in the PFC mediate the relationship between handgrip strength and cognitive performance (p > 0.05).

CONCLUSION

The present study provides evidence for a positive neurobehavioral relationship between cortical hemodynamics and cognitive performance. Our findings further imply that in younger adults higher levels of handgrip strength positively influence cortical hemodynamics although the latter did not necessarily culminate in better cognitive performance. Future research should examine whether the present findings can be generalized to other cohorts (e.g., older adults).

Grip Strength and the Risk of Cognitive Decline and Dementia: A Systematic Review and Meta-Analysis of Longitudinal Cohort Studies

Purpose: Loss of grip strength and cognitive impairment are prevalent in the elderly, and they may share the pathogenesis in common. Several original studies have investigated the association between them, but the results remained controversial. In this systematic review and meta-analysis, we aimed to quantitatively determine the relationship between baseline grip strength and the risk of cognitive impairment and provide evidence for clinical work.

Methods: We performed a systematic review using PubMed, EMBASE, Cochrane, and Web of Science up to March 23, 2020, and focused on the association between baseline grip strength and onset of cognitive impairment. Next, we conducted a meta-analysis using a hazard ratio (HR) and 95% confidence interval (CI) as effect measures. Heterogeneity between the studies was examined using I² and p-value. Sensitivity analyses and subgroup analyses were also performed, and publication bias was assessed by Begg's and Egger's tests.

Results: Fifteen studies were included in this systematic review. After sensitivity analyses, poorer grip strength was associated with more risk of cognitive decline and dementia (HR = 1.99, 95%CI: 1.71–2.32; HR = 1.54, 95%CI: 1.32–1.79, respectively). Furthermore, subgroup analysis indicated that people with poorer strength had more risk of Alzheimer's disease (AD) and non-AD dementia (HR = 1.41, 95%CI: 1.09–1.81; HR = 1.45, 95%CI: 1.10–1.91, respectively).

Conclusions: Lower grip strength is associated with more risk of onset of cognitive decline and dementia despite of subtype of dementia. We should be alert for the individuals with poor grip strength and identify cognitive dysfunction early.

Deterioration in Motor Function Over Time in Older Adults With Type 2 Diabetes is Associated with Accelerated Cognitive Decline

OBJECTIVE

Type 2 diabetes (T2D) is associated with motor impairments and a higher dementia risk. The relationships of motor decline with cognitive decline in T2D older adults has rarely been studied. Using data from the Israel Diabetes and Cognitive Decline study (N = 892), we examined associations of decline in motor function with cognitive decline over a 54-month period.

METHODS

Motor function measures were strength (handgrip) and gait speed (time to walk 3 m). Participants completed a neuropsychologic battery of 13 tests transformed into z-scores, summarized into 4 cognitive domains: episodic memory, attention/working memory, executive functions, and language/semantic categorization. The average of the 4 domains' z-scores defined global cognition. Motor and cognitive functions were assessed in 18-months intervals. A random coefficients model delineated longitudinal relationships of cognitive decline with baseline and change from baseline in motor function, adjusting for sociodemographic, cardiovascular, and T2D-related covariates.

RESULTS

Slower baseline gait speed levels were significantly associated with more rapid decline in global cognition (P = .004), language/semantic categorization (P = .006) and episodic memory (P = .029). Greater decline over time in gait speed was associated with an accelerated rate of decline in global cognition (P = .050), attention/working memory (P = .047) and language/semantic categorization (P<.001). Baseline strength levels were not associated with cognitive decline but the rate of declining strength was associated with an accelerated decline in executive functions (P = .025) and language/semantic categorization (P = .006).

CONCLUSION

In T2D older adults, the rate of decline in motor function, beyond baseline levels, was associated with accelerated cognitive decline, suggesting that cognitive and motor decline share common neuropathologic mechanisms in T2D.

Prevalence of Major Cardiovascular Disease Events Among People Diagnosed With Schizophrenia Who Have Sleep Disturbance, Sedentary Behavior, or Muscular Weakness

Objective

To estimate prevalence of major cardiovascular events among people with schizophrenia who had experience of sleep disturbance, sedentary behavior or muscular weakness, and assess evidence for raised prevalence in these individuals compared to people with schizophrenia without these characteristics.

Methods

UK Biobank data on individuals diagnosed with schizophrenia (n = 1544) were used to examine the prevalence of major cardiovascular events, specifically myocardial infarction, stroke, heart failure and cardiovascular death, among participants with candidate risk factors. Generalized linear models were fitted to estimate prevalence ratios (PRs) for major cardiovascular events among participants with self-reported sleep disturbance, self-reported sedentary behavior, and muscular weakness measured using a handgrip dynamometer. These ratios were adjusted for QRISK3 score—a validated cardiovascular risk prediction algorithm for the UK population.

Results

Prevalence of major cardiovascular events was significantly higher among participants with daytime sleepiness, independent of QRISK3 score, and snoring, a proxy for sleep-disordered breathing (adjusted PR 1.26; 95% CI 1.03, 1.55, P = .03). Prevalence was also independently higher among participants with low muscular strength (adjusted PR1.36; 95% CI 1.05, 1.75, P = .02). The adjusted prevalence ratios among participants with short or prolonged sleep duration, insomnia, or sedentary behavior did not indicate independently raised prevalence among these groups.

Conclusion

Prevalence of major cardiovascular events among people with schizophrenia was higher in participants with muscular weakness and sleep disturbance evidenced by daytime sleepiness. Further research is required to determine how these factors can be routinely identified and addressed in the clinical management of cardiovascular risk among patients with schizophrenia.

Role for Physical Fitness in the Association between Age and Cognitive Function in Older Adults: A Mediation Analysis of the SABE Colombia Study

Objectives. We investigated the association between physical fitness and cognitive status. Further, we examined whether physical fitness mediates the association between cognitive functioning and aging. Design. Cross-sectional study. Setting. Urban and rural Colombian older adults. Methods. 4416 participants from the SABE study were included in the current analysis. Physical fitness was assessed with the handgrip test and the usual gait speed test. Cognitive status was evaluated through the Folstein Mini-Mental State Examination. A parallel mediation path was used to test the possible mediator role of physical fitness between aging and cognitive functioning. Results. Older adults with lower handgrip strength (HGS) were more likely to have mild-cognitive status than older adults with healthy HGS (OR = 1.53, 95% CI = 1.15; 2.02). In addition, older adults with a slower gait speed were more likely to have mild cognitive impairment (OR = 2.05, 95% CI = 1.54; 2.78). Age had an inverse relationship with cognitive function (β = −0.110, 95% CI = −0.130; −0.100) and it was also inversely associated with HGS (β = −0.003, 95% CI = −0.005; −0.002) and gait speed (β = −0.010, 95% CI = −0.011; −0.009). The indirect effects, which indicate that the effect of age on cognitive function is transmitted through mediators, showed that both gait speed (β = −0.028, 95% CI = −0.036; −0.020) and HGS (β = −0.014, 95% CI = −0.024; −0.005) were independent mediators of the detrimental effect of aging on cognitive function. Conclusions. Physical fitness mediates the effects of aging on cognitive functioning. Our findings suggest that physical activity can be a key factor to prevent cognitive deterioration during aging process.

M, B.W.C. S, P.V. V, Ramaswamy P. How does cognitive function measured by the reaction time and critical flicker fusion frequency correlate with the academic performance of students?

BACKGROUND

The reaction time (RT) is "the time taken for the appearance of rapid voluntary reaction by an individual following a stimulus, either auditory or visual" and the Critical Flickering Fusion Frequency (CFFF) is "the rate at which successively presented light stimuli appear to be steady and continuous". RT and CFFF are commonly used for the assessment of cognitive functions that are known to influence academic performance. However, data about the exact correlation between these are scarce, particularly in India. This research aimed to study the association between visual RT (VRT), auditory RT (ART) and CFFF and their impact on the academic performance of undergraduate students.

METHODS

This cross-sectional study was conducted on 700 students of Faculty of Medicine and Dentistry at a private medical university in South India, during the period from 2015 to 2017. The VRT, ART and CFFF were evaluated, and the best out of three subsequent attempts was recorded. The mean score (in percentage) of the three best marks out of the five internal assessments for the course during each academic year was considered for analysis. The association between the different cognitive tests and the average academic performance was analysed.

RESULTS

Female students had faster VRT (n = 345, mean = 243.97, SD = 83.87) than male students (n = 273, mean = 274.86, SD = 96.97) (p = 0.001). VRT and ART had a moderate negative correlation with academic performance (for ART, r = - 0.42, p < 0.001; for VRT; r = - 0.40, p < 0.001). CFFF had a very weak positive correlation with academic performance (r = 0.19, p = 0.01). The only independent predictors of academic performance were RT and gender (Adjusted R2 = 0.11).

CONCLUSION

Although there is a correlation between CFFF and cognitive function, our study showed only a weak correlation between CFFF and academic performance. Female students had faster RTs, and gender was an independent predictor of academic performance. Rather, students with faster RTs appear to have an advantage in academic performance.

Grip Strength, Neurocognition, and Social Functioning in People WithType-2 Diabetes Mellitus, Major Depressive Disorder, Bipolar Disorder, and Schizophrenia

BACKGROUND

Frailty is a common syndrome among older adults and patients with several comorbidities. Grip strength (GS) is a representative parameter of frailty because it is a valid indicator of current and long-term physical conditions in the general population and patients with severe mental illnesses (SMIs). Physical and cognitive capacities of people with SMIs are usually impaired; however, their relationship with frailty or social functioning have not been studied to date. The current study aimed to determine if GS is a valid predictor of changes in cognitive performance and social functioning in patients with type-2 diabetes mellitus and SMIs.

METHODS

Assessments of social functioning, cognitive performance, and GS (measured with an electronic dynamometer) were conducted in 30 outpatients with type 2 diabetes mellitus, 35 with major depressive disorder, 42 with bipolar disorder, 30 with schizophrenia, and 28 healthy controls, twice during 1-year, follow-up period. Descriptive analyses were conducted using a one-way analysis of variance for continuous variables and the chi-squared test for categorical variables. Differences between groups for the motor, cognitive, and social variables at T1 and T2 were assessed using a one-way analysis of covariance, with sex and age as co-variates (p < 0.01). To test the predictive capacity of GS at baseline to explain the variance in cognitive performance and social functioning at T2, a linear regression analysis was performed (p < 0.05).

RESULTS

Predictive relationships were found among GS when implicated with clinical, cognitive, and social variables. These relationships explained changes in cognitive performance after one year of follow-up; the variability percentage was 67.7%, in patients with type-2 diabetes mellitus and 89.1% in patients with schizophrenia. Baseline GS along with other variables, also predicted changes in social functioning in major depressive disorder, bipolar disorder, and schizophrenia, with variability percentages of 67.3, 36, and 59%, respectively.

CONCLUSION

GS combined with other variables significantly predicted changes in cognitive performance and social functioning in people with SMIs or type-2 diabetes mellitus. Interventions aimed to improve the overall physical conditions of patients who have poor GS could be a therapeutic option that confers positive effects on cognitive performance and social functioning.

Weakness and cognitive impairment are independently and jointly associated with functional decline in aging Americans

BACKGROUND

Discovering how certain health factors contribute to functional declines may help to promote successful aging.

AIMS

To determine the independent and joint associations of handgrip strength (HGS) and cognitive function with instrumental activities of daily living (IADL) and activities of daily living (ADL) disability decline in aging Americans.

METHODS

Data from 18,391 adults aged 50 years and over who participated in at least one wave of the 2006-2014 waves of the Health and Retirement Study were analyzed. A hand-held dynamometer assessed HGS and cognitive functioning was examined with a modified version of the Telephone Interview of Cognitive Status. IADL and ADL abilities were self-reported. Participants were stratified into four distinct groups based on their HGS and cognitive function status. Separate covariate-adjusted multilevel models were conducted for the analyses.

RESULTS

Participants who were weak, had a cognitive impairment, and had both weakness and a cognitive impairment had 1.70 (95% confidence interval (CI) 1.57-1.84), 1.97 (CI 1.74-2.23), and 3.13 (CI 2.73-3.59) greater odds for IADL disability decline, respectively, and 2.26 (CI 2.03-2.51), 1.26 (CI 1.05-1.51), and 4.48 (CI 3.72-5.39) greater odds for ADL disability decline, respectively.

DISCUSSION

HGS and cognitive functioning were independently and jointly associated with IADL and ADL disability declines. Individuals with both weakness and cognitive impairment demonstrated substantially higher odds for functional decline than those with either risk factor alone.

CONCLUSIONS

Including measures of both HGS and cognitive functioning in routine geriatric assessments may help to identify those at greatest risk for declining functional capacity.

Of Sound Mind and Body: Exploring the Diet-Strength Interaction in Healthy Aging

Strength is a vital component of healthy aging. However, “strength” comes in different forms (includes both physical and mental aspects) and can look different at various phases of adult life. Healthy eating and regular exercise are clearly important pillars for strength. This paper proposes a framework that underlines the value of protein foods and resistance exercise for aging strong.

Exercise as Medicine for Mental and Substance Use Disorders: A Meta-review of the Benefits for Neuropsychiatric and Cognitive Outcomes

BACKGROUND

Exercise may improve neuropsychiatric and cognitive symptoms in people with mental disorders, but the totality of the evidence is unclear. We conducted a meta-review of exercise in (1) serious mental illness (schizophrenia spectrum, bipolar disorder and major depression (MDD)); (2) anxiety and stress disorders; (3) alcohol and substance use disorders; (4) eating disorders (anorexia nervosa bulimia nervosa, binge eating disorders, and (5) other mental disorders (including ADHD, pre/post-natal depression).

METHODS

Systematic searches of major databases from inception until 1/10/2018 were undertaken to identify meta-analyses of randomised controlled trials (RCTs) of exercise in people with clinically diagnosed mental disorders. In the absence of available meta-analyses for a mental disorder, we identified systematic reviews of exercise interventions in people with elevated mental health symptoms that included non-RCTs. Meta-analysis quality was assessed with the AMSTAR/+.

RESULTS

Overall, we identified 27 systematic reviews (including 16 meta-analyses representing 152 RCTs). Among those with MDD, we found consistent evidence (meta-analyses = 8) that exercise reduced depression in children, adults and older adults. Evidence also indicates that exercise was more effective than control conditions in reducing anxiety symptoms (meta-analyses = 3), and as an adjunctive treatment for reducing positive and negative symptoms of schizophrenia (meta-analyses = 2). Regarding neurocognitive effects, exercise improved global cognition in schizophrenia (meta-analyses = 1), children with ADHD (meta-analyses = 1), but not in MDD (meta-analyses = 1). Among those with elevated symptoms, positive mental health benefits were observed for exercise in people with pre/post-natal depression, anorexia nervosa/bulimia nervosa, binge eating disorder, post-traumatic stress disorder and alcohol use disorders/substance use disorders. Adverse events were sparsely reported.

CONCLUSION

Our panoramic meta-overview suggests that exercise can be an effective adjunctive treatment for improving symptoms across a broad range of mental disorders.

Associations of grip strength with retinal and choroidal thickness in patients with type 2 diabetes mellitus without retinopathy: a cross-sectional study

OBJECTIVE

To evaluate the associations of grip strength with retinal or choroidal thickness in patients with type 2 diabetes mellitus without retinopathy.

DESIGN

Observational study-cross-sectional design.

SETTING AND PARTICIPANTS

This study included the Chinese patients with type 2 diabetes without retinopathy registered in the community health system in Guangzhou, China.

MEASURES

The grip strength in both hands were measured by using a dynamometer. The retinal and choroidal thickness in macular region stratified by Early Treatment Diabetic Retinopathy Study (ETDRS) sectors were measured by a swept-source optical coherence tomography.

RESULTS

A total of 1029 patients were included. Both retinal thickness and choroidal thickness decreased with the lower quartile of grip strength. Regression analyses indicated that the average retinal and choroidal thickness increased by 0.14 µm (95% CI: 0.03 to 0.25 µm, p=0.011) and 0.57 µm (95% CI: 0.03 to 1.11 µm, p=0.037), respectively, for each additional kilogram of grip strength following adjustment for age and sex. Further adjustments were made for axial length, haemoglobin A1c, length of time the patient had diabetes, insulin usage, height, weight and systolic and diastolic blood pressure, which resulted in an average retinal and choroidal thickness increase of 0.13 µm (95% CI: 0.02 to 0.24 µm, p=0.024) and 0.65 µm (95% CI: 0.13 to 1.16 µm, p=0.013), respectively, for each additional kilogram of grip strength. Consistent results were obtained in the analyses in ETDRS 9 sectors.

CONCLUSION

Lower hand grip strength was found to be significantly associated with thinner retinal and choroidal layers in patients with diabetes. Grip strength may provide a useful and easily administered indicator of retinal status in patients with diabetes.

Longitudinal Assessment and Functional Neuroimaging of Movement Variability Reveal Novel Insights Into Motor Dysfunction in Clinical High Risk for Psychosis

Motor dysfunction in youth at clinical high risk (CHR) for psychosis is thought to reflect abnormal neurodevelopment within cortical-subcortical motor circuits and may be important for understanding clinical trajectories of CHR individuals. However, to date, our perspective of brain-behavior relationships has been informed solely by cross-sectional correlational studies linking behavior in the lab to brain structure or respective resting-state network connectivity. Here, we assess movement dysfunction from 2 perspectives: study 1 investigates the longitudinal progression of handwriting variability and positive symptoms in a sample of 91 CHR and healthy controls during a 12-month follow-up and study 2 involves a multiband functional magnetic resonance imaging task exploring the relationship between power grip force stability and motor network brain activation in a subset of participants. In study 1, we found that greater handwriting variability was a stable feature of CHR participants who experienced worse symptom progression. Study 2 results showed that CHR individuals had greater variability in their grip force and greater variability was related to decreased activation in the associative cortico-striatal network compared to controls. Motor variability may be a stable marker of vulnerability for psychosis risk and possible indicator of a vulnerable cortico-striatal brain network functioning in CHR participants, although the effects of antipsychotic medication should be considered.

Grip strength is associated with markers of central hemodynamics

Objectives. Reduced muscular strength (measured by grip strength) has been associated with an increased risk of cardiovascular complications. Further research is needed to identify how muscular strength is associated with various markers of cardiovascular function to provide at least some mechanistic explanation for observed interrelations. We, therefore, addressed the question of whether handgrip (HG) strength is associated with descriptors of peripheral and central hemodynamics in the population of healthy individuals. Design. Two hundred thirty-one healthy volunteers (90 men and 141 women, mean age 54 years) were studied. Patients were asked to perform the maximum handgrip trial in the standing position with the dominant arm, using hydraulic hand dynamometer. Applanation tonometry was used to execute the non-invasive assessment of the pressure waveform. Results. HG strength was associated with various markers of hemodynamics and clinical characteristics, e.g. correlated significantly and positively with BMI [body mass index, r = 0.21, p = .001], PPA [pulse pressure amplification, r = 0.43, p < .0001], Tr [time to return of pressure wave, r = 0.43, p < .0001] and significantly and negatively with AP [augmentation pressure, r = -0.45, p < .0001]. Multiple linear regression showed that sex, handgrip and mean blood pressure were independently associated with AP (R² = 0.38), PPA (R² = 0.21) and Tr (R² = 0.29). Conclusions. Our study demonstrated the association between handgrip strength and central hemodynamic metrics. These interactions may add a mechanistic explanation for the role of muscle strength as a risk marker for incident cardiovascular complications.

Allometrically scaled explosive strength, but not static strength or maximal oxygen uptake is associated with better central processing time in young males

BACKGROUND

We aimed to examine the associations of cardiorespiratory fitness (CRF), static strength and explosive strength with cognitive functions in young males.

METHODS

Eighty-six young males (age 16-24 years) participated in the study and took part in a number of tests including: static strength (grip strength test), explosive strength (Sargent jump test), and CRF (via direct measure of maximal oxygen uptake [VO2max]). Static strength and explosive strength were scaled by allometrically modeled skeletal muscle mass (SMM) and height while VO2max was scaled by SMM and body mass (BM). Cognition was assessed by inhibitory control, simple and choice reaction time tasks using computerized Cambridge Neuropsychological Test Battery (CANTAB). Central processing time was measured by surface electromyography changes in isometric contraction response to an audio stimulus.

RESULTS

VO2max scaled by BM (but not SMM), was associated with better central processing time and stop-signal reaction time (SSRT). Explosive strength was also associated with better central processing time independent of VO2max. However, static strength was not associated with cognition.

CONCLUSIONS

The results suggest that explosive strength is a better predictor of central processing than static strength or VO2max in young males. Longitudinal studies are needed to examine whether explosive strength training in youth would improve central processing time.

Resistance, vulnerability and resilience: A review of the cognitive cerebellum in aging and neurodegenerative diseases

In the context of neurodegeneration and aging, the cerebellum is an enigma. Genetic markers of cellular aging in cerebellum accumulate more slowly than in the rest of the brain, and it generates unknown factors that may slow or even reverse neurodegenerative pathology in animal models of Alzheimer's Disease (AD). Cerebellum shows increased activity in early AD and Parkinson's disease (PD), suggesting a compensatory function that may mitigate early symptoms of neurodegenerative pathophysiology. Perhaps most notably, different parts of the brain accumulate neuropathological markers of AD in a recognized progression and generally, cerebellum is the last brain region to do so. Taken together, these data suggest that cerebellum may be resistant to certain neurodegenerative mechanisms. On the other hand, in some contexts of accelerated neurodegeneration, such as that seen in chronic traumatic encephalopathy (CTE) following repeated traumatic brain injury (TBI), the cerebellum appears to be one of the most susceptible brain regions to injury and one of the first to exhibit signs of pathology. Cerebellar pathology in neurodegenerative disorders is strongly associated with cognitive dysfunction. In neurodegenerative or neurological disorders associated with cerebellar pathology, such as spinocerebellar ataxia, cerebellar cortical atrophy, and essential tremor, rates of cognitive dysfunction, dementia and neuropsychiatric symptoms increase. When the cerebellum shows AD pathology, such as in familial AD, it is associated with earlier onset and greater severity of disease. These data suggest that when neurodegenerative processes are active in the cerebellum, it may contribute to pathological behavioral outcomes. The cerebellum is well known for comparing internal representations of information with observed outcomes and providing real-time feedback to cortical regions, a critical function that is disturbed in neuropsychiatric disorders such as intellectual disability, schizophrenia, dementia, and autism, and required for cognitive domains such as working memory. While cerebellum has reciprocal connections with non-motor brain regions and likely plays a role in complex, goal-directed behaviors, it has proven difficult to establish what it does mechanistically to modulate these behaviors. Due to this lack of understanding, it's not surprising to see the cerebellum reflexively dismissed or even ignored in basic and translational neuropsychiatric literature. The overarching goals of this review are to answer the following questions from primary literature: When the cerebellum is affected by pathology, is it associated with decreased cognitive function? When it is intact, does it play a compensatory or protective role in maintaining cognitive function? Are there theoretical frameworks for understanding the role of cerebellum in cognition, and perhaps, illnesses characterized by cognitive dysfunction? Understanding the role of the cognitive cerebellum in neurodegenerative diseases has the potential to offer insight into origins of cognitive deficits in other neuropsychiatric disorders, which are often underappreciated, poorly understood, and not often treated.

Handgrip Strength Is Associated With Hippocampal Volume and White Matter Hyperintensities in Major Depression and Healthy Controls: A UK Biobank Study

OBJECTIVE

Emerging evidence suggests that handgrip strength (a proxy for muscular fitness) is associated with better cognitive performance in people with major depressive disorder (MDD). The underlying processes are unclear, although hippocampal volume (HCV) reductions and white matter hyperintensities (WMHs) have been implicated. Therefore, we investigated the associations between handgrip strength and various brain region volumes and WMHs in MDD and healthy controls (HCs).

METHODS

This study is a cross-sectional analysis of handgrip strength and neuroimaging data from the UK Biobank. Generalized linear models were used to assess the relationship between grip strength and gray matter, white matter, total brain volume, left and right hippocampus volume, and WMHs in MDD and HCs, adjusting for age, sex, education, and body weight.

RESULTS

The sample included 527 people with MDD (54.3 ± 7.3 years, 37.2% male) and 1764 HCs (56.6 ± 7.2 years, 53% male). In MDD, stronger handgrip was significantly associated with increased left (coefficient ± SE = 108.1 ± 27.6, t = 3.92) and right (76.8 ± 30.4, t = 2.53) HCV. In HCs, only right HCV related to handgrip strength (44.8 ± 18.1, t = 2.47). Interaction analyses found stronger associations between grip strength and HCV in MDD compared with HCs, for both hippocampal regions. Stronger handgrip was associated with reduced WMHs in people with MDD (-0.24 ± 0.07, t = -3.24) and HCs (-0.11 ± 0.04, t = -2.47). Maximal handgrip strength was not associated with gray matter, white matter, or total brain volumes in either group.

CONCLUSIONS

Stronger grip strength is associated with greater left and right HCV and reduced WMHs in MDD. Future research should investigate directionality and consider if interventions targeting strength/muscular fitness can improve brain health and reduce the neurocognitive abnormalities associated with MDD.

Resistance training in patients with schizophrenia: Concept and proof of principle trial

Resistance training has been shown to contribute to the prevention and management of cardiovascular diseases, which is why it can help reducing morbidity and mortality in schizophrenia patients. Moreover, positive effects on different schizophrenia symptom domains have been proposed. However, a specific resistance training tailored to the needs of schizophrenia patients and its evaluation is still lacking. The objective in this proof of principle trial was to evaluate the feasibility and efficacy of a newly developed 12-week resistance program according to current recommendations of the WHO and the American College of Sports Medicine. We employed a single blind, parallel assignment clinical trial design with participants randomized to attend either a resistance training including three 50min units per week or a balance and tone program as control condition. The primary outcome was the impact on health-related difficulties assessed with the World Health Organization Disability Assessment Schedule (WHO-DAS). Secondary outcome parameters included the level of functioning, schizophrenia symptoms, selected cognitive parameters as well as risk factors for cardiovascular diseases. In our proof of principle trial, we could not find significant time or group effects of resistance training on the WHO-DAS. However, we could observe significant positive effects on the level of functioning assessed with the Global Assessment of Functioning Scale (GAF) over the course of time, which were more pronounced in the intervention group. Our findings indicated that patients with schizophrenia could safely participate in resistance training with relevant improvements in their level of functioning. Well-powered replication trials are needed to provide more efficacy data.