Lifetime occupation and physical function: a prospective cohort study on persons aged 80 years and older living in a community

Cognitive Reserve Relationship with Physical Performance in Dementia-Free Older Adults: The MIND-China Study

Background

Cognitive reserve (CR) may be beneficial to the physical function of the elderly.

Objective

We aimed to examine the association of CR proxies and composite CR capacity with physical function in older adults while considering age and sex.

Methods

This population-based cross-sectional study included 4,714 participants living in rural China (age≥60 years) who were dementia-free. Structural equation modeling was used to generate a composite CR score by integrating early-life education, midlife occupational complexity, and late-life mental activity and social support. The Short Physical Performance Battery (SPPB) measured physical function. Data were analyzed using linear regression models.

Results

Greater educational attainment and mental activity were associated with higher composite SPPB scores and those of its three subtests (p < 0.05). Skilled occupations were associated with higher SPPB, chair stand, and walking speed scores, while greater social support was associated with higher scores for SPPB and chair stand (p < 0.05). Each 1-point increase in composite CR score (range: -0.77 to 1.03) was linearly associated with a multivariable-adjusted β-coefficient of 0.74 (95% confidence interval (CI): 0.58-0.89) for total SPPB score, 0.16 (0.10-0.22) for balance test, 0.40 (0.32-0.48) for chair stand, and 0.17 (0.12-0.23) for walking speed. The association between higher composite CR and total SPPB scores was more prominent in those≥75 years than those aged 60-74 years (p < 0.01). There was no statistical interaction of composite CR score and sex in physical function.

Conclusions

High CR is associated with better physical function, especially among older adults (≥75 years).

Weak grip strength among persons with multiple sclerosis having minimal disability is not related to agility or integrity of the corticospinal tract

INTRODUCTION

Mobility impairment is common in multiple sclerosis (MS); however, agility has received less attention. Agility requires strength and neuromuscular coordination to elicit controlled propulsive rapid whole-body movement. Grip strength is a common method to assess whole body force production, but also reflects neuromuscular integrity and global brain health. Impaired agility may be linked to loss of neuromuscular integrity (reflected by grip strength or corticospinal excitability).

OBJECTIVES

We aimed to determine whether grip strength would be associated with agility and transcranial magnetic stimulation (TMS)-based indices of corticospinal excitability and inhibition in persons with MS having low disability. We hypothesized that low grip strength would predict impaired agility and reflect low corticospinal excitability.

METHODS

We recruited 34 persons with relapsing MS (27 females; median [range] age 45.5 [21.0-65.0] years) and mild disability (median [range] Expanded Disability Status Scale 2.0 [0-3.0]), as well as a convenience sample of age- and sex-matched apparently healthy controls. Agility was tested by measuring hop length during bipedal hopping on an instrumented walkway. Grip strength was measured using a calibrated dynamometer. Corticospinal excitability and inhibition were examined using TMS-based motor evoked potential (MEP) and corticospinal silent period (CSP) recruitment curves, respectively.

RESULTS

MS participants had significantly lower grip strength than controls independent of sex. Females with and without MS had weaker grip strength than males. There were no statistically significant sex or group differences in agility. After controlling for sex, weaker grip strength was associated with shorter hop length in controls only (r = 0.645, p < .05). Grip strength did not significantly predict agility in persons with MS, nor was grip strength predicted by corticospinal excitability or inhibition.

CONCLUSIONS

In persons with MS having low disability, grip strength (normalized to body mass) was reduced despite having intact agility and walking performance. Grip strength was not associated with corticospinal excitability or inhibition, suggesting peripheral neuromuscular function, low physical activity or fitness, or other psychosocial factors may be related to weakness. Low grip strength is a putative indicator of early neuromuscular aging in persons with MS having mild disability and normal mobility.

Exploring workability in an older working population: associations with cognitive functioning, sleep quality, and technostress

Objective

This observational study investigates workability and its associations with cognitive functioning, sleep quality and technostress among an older working population, also shedding light on potential differences between two occupational categories with different work schedules.

Methods

Workers aged over 50, employed in different working sectors (banking/finance, chemical and metal-mechanic industry) were administered a self- report questionnaire including Work Ability Index (WAI), cognitive tests (Stroop Color Task, Corsi Blocks, Digit Span), sleep quality questionnaires (Pittsburgh Sleep Quality Index-PSQI; Insomnia Severity Index-ISI; Ford Insomnia Response to Stress Test-FIRST) and technostress scale. Linear regression models evaluated associations among variables, interaction effects investigated potential moderators.

Results

A total of 468 aged workers categorized as white (WCWs; N = 289, 62%) or blue collars (BCWs; N = 179, 38%) were enrolled; most BCWs (N = 104; 58%) were night shift workers. WCWs reported higher workability, cognitive functioning, sleep quality and lower technostress (except for invasion and privacy subscales) than BCWs. Associations between cognitive functioning and workability were statistically significant only for BCWs [slopes equal to 0.2 (0.33), 0.8 (0.34), -0.02 (0.001) for Memory Span Corsi, Block Span Digit and Interference Speed respectively]; additionally, sleep quality significantly moderated this association (p = 0.007). Higher levels of technostress were associated with lower workability, and this relationship was stronger for BCWs.

Conclusion

The aging of the workforce has important implications for occupational health and safety. Our findings suggest potential interventions and protective measures to promote older workers' wellbeing; blue-collar workers particularly should benefit from tailored intervention to sustain workability and prevent technostress, considering the role of healthy sleep habits promotion.

Longitudinal profiles of occupational physical activity during late midlife and their association with functional limitations at old age: a multi-cohort study

OBJECTIVE

The aim was to examine longitudinal profiles of occupational physical activity (OPA) from midlife to retirement and to investigate how the different OPA-profiles are associated with mobility limitations (ML) and activities of daily living (ADL-disability) at old age.

METHODS

Harmonized data from two cohort studies from Finland and the United States, that have followed people from midlife until old age were used. Repeated measurements of self-reported OPA were collected during approximately 11- to 12-year period. Persons who had data on OPA from ≥ 2 time points during the period from mid-working life to retirement were included. Latent class growth analysis was used to identify OPA-profiles. Risk ratios (RRs) with 95% confidence intervals for the associations of the OPA-profiles and later life MLs and ADL-disability were estimated.

RESULTS

Three OPA-profiles were identified in both cohorts: high-persistent, moderate-fluctuating, and low-persistent. For majority OPA remained stable: for workers reporting high or low levels of OPA at midlife, the physical demands of work likely persisted, whereas people reporting moderate level OPA had high fluctuation in their exposure level. Members of high-persistent and moderate-fluctuating OPA-profiles had increased risk of subsequent MLs at old age. The RRs for ADL-disability did not differ between the profiles.

CONCLUSIONS

Perceived OPA remains rather stable for workers reporting high or low physical work demands during midlife, yet fluctuating profiles also exist. Workers exposed to high or moderate OPA have higher risk for MLs when they reach old age. Establishing safe and health-promoting levels of OPA during late working life might have positive long-term consequences on healthy ageing.

Activity engagement and cognitive function among chinese older adults: moderating roles of gender and age

BACKGROUND

Many studies have found that engaging in activities, including physical exercise, social interaction, and cognitive training, is beneficial for preventing cognitive decline among older adults; however, the demographic differences in the association between activity engagement and cognitive functions remain understudied. This study investigates: (a) the influence of activity engagement on cognitive functions among Chinese older adults, and (b) the moderating roles of age and gender in these associations .

METHODS

The data were derived from the China Health and Retirement Longitudinal Study in 2018, which included 9803 participants aged 60 or older. A multiple regression model was used to test the study hypotheses.

RESULTS

Engaging in physical activity (b = 1.578, p < .001), social interaction (b = 1.199, p < .001), and cognitive activity (b = 1.468, p < .001) was positively associated with cognitive functions, whereas the effect of volunteer activities on cognitive functions was not significant (b = -.167, p = .390). Light- and moderate-intensity activities were beneficial for cognition (light: b = .847, p < .001; moderate: b = 1.189, p < .001), but vigorous-intensity activity was negatively related to cognition (b = -.767, p < .001). In addition, women and participants with advanced age appeared to benefit more from cognitive activities than their male and younger counterparts, respectively (gender: b = 1.217, p = .002; age: b = .086, p = .004). The adverse effects of vigorous-intensity activities (including agricultural work) on cognitive health were stronger for women and younger participants (gender: b = -1.472, p < .001; age: b = .115, p < .001). The protective effects of moderate-intensity activities on people's cognition increased with increasing age (b = .055, p = .012).

CONCLUSIONS

The findings indicate that participating in physical, social, and cognitive activities can help older adults to maintain cognitive health. They suggest that older adults should select activities while considering activity intensity and their individual characteristics.

Association between sociodemographic factors and mobility limitation among older adults: a systematic review and meta-analysis protocol

BACKGROUND

Mobility is an independent predictor of physical functionality, healthy ageing, and quality of life. Various literatures have associated mobility limitation in older adulthood with demographic and socioeconomic factors. Hence, we propose a systematic review and meta-analysis to synthesise the association between sociodemographic factors and mobility limitations in older adults.

METHODS AND ANALYSES

This protocol was written according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines. We will perform a comprehensive search of all observational studies that assessed the relationship between age, gender, race, place, education, income, occupation, social status, and walking distance, time, or speed. Electronic databases (MEDLINE, Web of Science, EMBASE, CINAHL, AgeLine, and SPORTDiscus) will be searched from inception to 28 February 2023. We will supplement the database search by manually searching the reference lists of all identified and relevant full-text articles. Two independent reviewers will be responsible for screening articles, data extraction, and assessment of bias. We will appraise the study quality and risk of bias using the Prediction Model Risk of Bias Assessment Tool (PROBAST). A meta-analysis will be considered if data from the selected studies are homogeneous, otherwise, a narrative synthesis of the extracted data will be presented.

DISCUSSION

Mobility limitation leads to frequent falls, dependency, morbidity, and death among older adults. This review is necessary, to identify and prioritise important sociodemographic factors during older adults' clinical assessment and policy development. It is the first phase of a multi-methods study seeking to develop a prognostic mobility trajectory for community-dwelling older adults.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022298570.

Association Between Paid Work and Health-Related Quality of Life Among Community-Dwelling Older Adults: The Sukagawa Study

In this study, we aimed to determine whether paid work has an impact on health-related quality of life (HRQOL) among older adults. Over three years, we longitudinally collected data from 5,260 community-dwelling older adults aged 75 years or older from a city in Japan. We assessed HRQOL using the Short-Form-8. We estimated the mean difference between the physical component summary (PCS) and the mental component summary (MCS) scores, which were stratified based on gender using multivariate, generalized estimating equation models. We further conducted a subgroup analysis based on the participants' occupational backgrounds. Engagement in paid work was associated with increased MCS scores across both genders and with increased PCS scores among women. In the subgroup analysis, only women who had previously worked as managerial workers showed an inverse association with MCS scores. In this population, engagement in paid work may be a crucial factor associated with well-being.

Grip strength, gait speed, and trajectories of cognitive function in community-dwelling older adults: A prospective study

Introduction

This study investigated whether grip strength and gait speed predict cognitive aging trajectories and examined potential sex-specific associations.

Methods

Community-dwelling older adults (n = 19,114) were followed for up to 7 years, with regular assessment of global function, episodic memory, psychomotor speed, and executive function. Group-based multi-trajectory modeling identified joint cognitive trajectories. Multinomial logistic regression examined the association of grip strength and gait speed at baseline with cognitive trajectories.

Results

High performers (14.3%, n = 2298) and low performers (4.0%, n = 642) were compared to the average performers (21.8%, n = 3492). Grip strength and gait speed were positively associated with high performance and negatively with low performance (P-values < 0.01). The association between grip strength and high performance was stronger in women (interaction P < 0.001), while gait speed was a stronger predictor of low performance in men (interaction P < 0.05).

Discussion

Grip strength and gait speed are associated with cognitive trajectories in older age, but with sex differences.

Highlights

There is inter-individual variability in late-life cognitive trajectories.Grip strength and gait speed predicted cognitive trajectories in older age.However, sex-specific associations were identified.In women, grip strength strongly predicted high, compared to average, trajectory.In men, gait speed was a stronger predictor of low cognitive performance trajectory.

Prevalence and risk factors of sarcopenia without obesity and sarcopenic obesity among Chinese community older people in suburban area of Shanghai: A cross-sectional study

Objectives

The aim of the present study was to explore the prevalence and risk factors of sarcopenia without obesity (S) and sarcopenic obesity (SO) among community-dwelling older people in the Chongming District of Shanghai, China, according to the Asian Working Group for Sarcopenia (AWGS) 2019 Consensus as the diagnostic criteria of sarcopenia.

Methods

In this cross-sectional study, a total of 1,407 subjects aged ≥65 years were included, where the mean age of the subjects was 71.91 ± 5.59 years and their mean body mass index (BMI) was 24.65 ± 3.32 kg/m². According to the Asian Working Group for Sarcopenia (AWGS) 2019 Consensus, sarcopenia was defined as a low appendicular skeletal muscle mass index (≤7.0 kg/m² in males and ≤5.7 kg/m² in females), decreased handgrip strength (<28.0 kg in males and <18.0 kg in females), and/or low gait speed (<1.0 m/s) or poor 5-time chair stand test (5CST) (≥12s). The SO met both the diagnostic criteria for sarcopenia and obesity, meanwhile obesity was defined as an increased percentage of body fat (PBF) (≥25% in males and ≥35% in females). Univariate and multiple logistic regression analyses were performed to explore the risk factors of both S and SO.

Results

The prevalence of S and SO was 9.74% (M: 9.29%, F: 10.05%) and 9.95% (M: 13.94%, F: 7.14%). Lower BMI (OR = 0.136, 95% CI: 0.054-0.340, p < 0.001), lower hip circumference (OR = 0.858, 95% CI: 0.816-0.903, p < 0.001), farming (OR = 1.632, 95% CI: 1.053-2.530, p = 0.028), higher high-density lipoprotein cholesterol (HDL-C) level (OR = 2.235, 95% CI: 1.484-3.367, p < 0.001), and a sleep duration <7 h (OR = 0.561, 95% CI: 0.346-0.909, p = 0.019) were risk factors for S. While aging (70-74 y, OR = 1.923, 95% CI: 1.122-3.295, p = 0.017; 75-79 y, OR = 3.185, 95% CI: 1.816-5.585, p < 0.001; ≥80 y, OR = 7.192, 95% CI: 4.133-12.513, p < 0.001), male (OR = 1.981, 95% CI: 1.351-2.904, p < 0.001), higher BMI (OR = 4.865, 95% CI: 1.089-21.736, p = 0.038), higher monocyte level (OR = 4.203, 95% CI: 1.340-13.181, p = 0.014), and a sleep duration >9 h (OR = 1.881, 95% CI: 1.117-3.166, p = 0.017) were risk factors for SO.

Conclusion

Our study showed the high prevalence of S and SO among community-dwelling older people in the Chongming District. The SO was more prevalent in males. Behavioral factors and lifestyle (such as farming and sleep duration) were associated more with the development of S, while age and male gender were associated more with the development of SO.

Role of socioeconomic, lifestyle, and clinical factors in the progression of cardiometabolic multimorbidity in China: A 10-year prospective cohort study

BACKGROUND AND AIMS

Cardiometabolic multimorbidity has become increasingly common over the past few decades. Little is known about how risk factors affect temporal progression of cardiometabolic multimorbidity. We aim to explore the role of socioeconomic, lifestyle, and clinical risk factors in the progression of cardiometabolic multimorbidity.

METHODS AND RESULTS

This prospective cohort study included 56,587 participants aged ≥45 years who were free of diabetes, stroke, and heart disease. Three clusters of risk factors were assessed and each on a 5-point scale: socioeconomic, lifestyle, and clinical factors. We used multi-state models (MSMs) to examine the roles of risk factors in five transitions of multimorbidity trajectory: from healthy to first cardiometabolic disease, first cardiometabolic disease to cardiometabolic multimorbidity, health to mortality, first cardiometabolic disease to mortality, and cardiometabolic multimorbidity to mortality. In MSMs, socioeconomic (HR: 1.21; 95% CI: 1.19-1.25) and clinical (HR: 1.53; 95% CI: 1.51-1.56) scales were associated with the transition from health to first cardiometabolic. Socioeconomic (HR: 2.39; 95% CI: 2.24-2.54) and lifestyle (HR: 1.22; 95% CI: 1.18-1.26) scales were associated with the transitions from first disease to cardiometabolic multimorbidity. In addition, socioeconomic and lifestyle scales were associated with increased risk of mortality in people without cardiometabolic disease, with first cardiometabolic disease, and with cardiometabolic multimorbidity.

CONCLUSIONS

Socioeconomic and lifestyle factors were not only important predictors of multimorbidity in those with existing cardiometabolic disease, but also important in shaping risk of mortality. However, clinical factors were the only key determinants of incidence of a first cardiometabolic disease.

Retirement status and frailty: a cross-sectional study of the phenotype of manual workers aged 50-70 years

BACKGROUND

The frailty phenotype is predictive of mortality and has been identified in the working population. This cross-sectional study aimed to investigate the prevalence of frailty and individual frailty symptoms among active and retired Danish manual workers and to delineate the relationship between frailty and lifestyle factors.

METHODS

Manual workers aged 50-70 years answered questions relating to the Fried criteria for frailty (weight loss, exhaustion, slowness, weakness and inactivity). Only men were included in the analyses and respondents were stratified according to work status: active workers (n = 1555), early retirees (n = 289) and workers retired at or after normal pension age (n = 291). Associations between pre-frailty/frailty, work status and various lifestyle factors were estimated using binomial logistic regression.

RESULTS

Overall, the prevalence of pre-frailty (one or two symptoms) and frailty (three or more symptoms) was 33.3% and 1.5%, respectively. Those who had retired early were more likely to be pre-frail/frail compared with active workers (odds ratio 2.20, 95% CI 1.61-3.01). Exhaustion was the most prominent symptom reported by 22.2% of active workers, 34.6% of early retirees and 16.5% of workers retired at normal retirement age. Lifestyle factors including obesity, physical inactivity and smoking but not alcohol intake were associated with pre-frailty/frailty.

CONCLUSION

Symptoms of frailty are identifiable and present among both active and retired manual workers. Data suggest discrepancies among Danish manual workers, with some having unhealthy lifestyles and being more prone to develop pre-frailty and frailty already in their sixth decade of life.

High Prevalence of Frailty and Prefrailty Status in Brazilian Patients Living with HIV

Frailty is associated with an increased probability of serious adverse health outcomes in the geriatric general population. People living with HIV have a higher prevalence of frailty. However, the magnitude of this problem in younger patients in South America is unknown. We aimed to determine the prevalence and factors associated with frailty. This is a cross-sectional study from the Brazilian cohort HIV-AIDS (CoBRA) developed between March and November of 2018, on patients ≥18 years of age. Frailty phenotype was assessed by original Fried criteria. The results were analyzed using descriptive statistics, while identification of factors related to frailty was assessed by using multivariate logistic regression. We enrolled 231 patients; all, but 2 were on antiretroviral therapy (ART). Median age was 45.6 interquartile range (36.7-52.1) years, 136 (58.9%) were male, and 86.7% self-identified as non-white. Mean CD4 count was 660 (±345) cells/mm³ and 83.5% had undetectable HIV plasma viral load (<50 copies/mL). Prevalence of frailty and prefrailty was 10.4% and 52.4%, respectively. A CD4 count <200 cells/mm³, depression, low income, and use of third-line ART were variables significantly associated with a greater risk to present frail or prefrail status. Frailty prevalence increases with age and is an important health problem to health care in HIV aging patients. It requires proper strategies to its early detection, prevention, and management.

The association between occupational categories and grip strength in Korean male workers

PURPOSE

This study explored the association between occupational categories and muscle strength using handgrip strength (HGS) while considering sociodemographic and health-related factors in Korean men using a national survey.

METHODS

Using cross-sectional data of 8380 men (59.9 ± 16.6 years of age), the occupational categories held the longest duration and HGS levels (normal vs. weak) were determined. Logistic regression was applied with adjustment for sociodemographic factors, work-related factors (working hours and schedule), and health-related factors (physical activity, sedentary time, resistance exercise, alcohol consumption, smoking status, chronic illness, subjective health status, weight category, metabolic syndrome, and protein intake).

RESULTS

Weak HGS prevalence was lowest in male managerial or professional workers (1.5%) and highest in male skilled agricultural, forestry, fishery, or craft and the related trades workers (16.4%). Compared to male managerial or professional workers, the odds for weak HGS increased in male service/sales workers (OR 2.41; 95% CI 1.45-3.99) and male manual workers [agricultural/forestry/fishery/craft and related trades workers, OR 2.94 (95% CI 1.78-4.83); equipment/machine operating/assembling workers, OR 1.68 (95% CI 1.05-2.71); and elementary workers, OR 3.43 (95% CI 1.95-6.05)] in the fully adjusted model. Regardless of age groups, income, working hours, strength exercise, and sedentary time levels, and chronic illness and metabolic syndrome status, male manual workers were more likely to have weak HGS compared to male non-manual workers.

CONCLUSION

Male manual workers may have a higher risk for weak muscle strength compared to male non-manual workers regardless of sociodemographic, work-related, and health-related factors.

Lifetime Duration of Exposure to Biomechanical Factors at Work as a Mediator of the Relationship Between Socioeconomic Position and Walking Speed

The study aimed to assess the proportion mediated by the duration of exposure to ergonomic factors at work on the relationship between socioeconomic position (SEP) and low walking speed. This cross-sectional study was performed on data collected at baseline on 19,704 men and 20,273 women 45-70 years old, currently or previously employed, enrolled in the Constances cohort. SEP was assigned through current or last occupation, categorized in three classes, based on the European Socioeconomic Classification. Walking speed was assessed through one measurement of normal walking for 3 m and dichotomized at the lowest quintile of the sex- and age- (5-year) specific distribution. Self-reported workplace exposure throughout working life to repetitive work, intense physical work, and lifting/carrying heavy loads was used to assess the duration of exposure to each factor, categorized in four classes. Through Poisson regression models, adjusted for BMI, smoking, alcohol intake, hypertension, physical activity, diabetes, cardiovascular diseases, and a cognitive score, the attenuation in the prevalence ratio (PR) of low walking speed by SEP produced by the inclusion of duration of exposure to each factor was evaluated. The mediating effect of work ergonomic exposures on the relationship between SEP and low walking speed was assessed using the weighted method by Vanderweele. In the fully adjusted model without ergonomic exposures, both men and women in the middle and the lowest SEP had a significantly increased risk of low walking speed compared with those in the highest SEP (men: PR = 1.30 and PR = 1.46, respectively; women: PR = 1.24 and PR = 1.45, respectively). The inclusion in separate regression models of exposure duration to repetitive work, intense physical work, and handling of heavy loads produced modest risk attenuations in both men and women, all smaller or around 10%. Mediation analysis revealed in both sexes significant mediation effects for most ergonomic exposures considered, although also with low mediation effects. Significant differences in walking speed by SEP were observed in this large sample, but the proportion of such differences explained by the duration of exposure to ergonomic factors at work was low using either the risk attenuation or the mediation analysis methods.

Association between physical limitations and working life exposure to carrying heavy loads assessed using a job-exposure matrix: CONSTANCES cohort

INTRODUCTION

Decline in physical performance with age varies among workers. We studied the association between lifetime exposure to carrying heavy loads and limitations in climbing stairs.

METHODS

We used data from the French CONSTANCES study. A biomechanical Job-Exposure Matrix (JEM) was combined with lifetime job histories to build a cumulative exposure score, and compared with reported limitations in climbing stairs using robust Poisson models, stratified by sex and educational level.

RESULTS

Of the 26,255 subjects, 618 men and 1,080 women reported difficulties in climbing stairs; this outcome was associated with cumulative exposure to carrying heavy loads: adjusted PR= 2.17 (1.75-2.73) for men, 1.50 (1.30-1.74) for women. The association was primarily seen among less educated subjects.

CONCLUSION

Cumulative work exposure to carrying heavy loads across the working life was associated with physical limitations in climbing stairs among the less educated in both genders.

The Association between Longest-Held Lifetime Occupation and Late-Life Cognitive Impairment: Korean Longitudinal Study of Aging (2006-2016)

The association between longest-held lifetime occupation and late-life cognitive impairment: Korean Longitudinal Study of Aging (2006–2016). Backgrounds: Our study hypothesized that occupation in adulthood may be one of the modifiable factors in cognitive performance. This follow-up study aimed to examine whether there was an association between the longest-held occupation in a lifetime and cognitive impairment. Methods: This study used data from the 2006, 2012, and 2016 waves of the Korean Longitudinal Study of Aging, and a total of 1733 subjects aged over 65 were included. Longest-held occupation in a lifetime was classified into blue-collar, pink-collar, and white-collar. Cognitive function was evaluated using the Korean version of the Mini-Mental State Examination. Results: In males, no significant associations were observed. In females, on the contrary, risk of cognitive impairment in the blue-collar occupation was consistently higher than in the white-collar occupation over the 10-year follow-up (2006, OR = 2.49, 95% CI 1.05–5.88; 2016, OR = 2.17, 95% CI 1.02−4.65). Conclusions: Lifetime occupation should be taken into consideration in the process of screening for cognitive decline in the elderly, especially females. This study needs to be interpreted cautiously in view of inherent data and methodological limitations.

Influences of Neck and/or Wrist Pain on Hand Grip Strength of Industrial Quality Proofing Workers

Background

The aim of this study was to analyze the interaction between neck and/or wrist pain and hand grip strength (HGS) and to investigate factors (age, sex, neck disorders, and carpal tunnel syndrome) influencing the HGS of industrial quality proofing workers (N = 145).

Methods

Standardized questionnaires [Neck Disability Index (NDI), Boston Carpal Tunnel Questionnaire] were used to evaluate existing neck and/or wrist pain. HGS measurements were performed in different wrist positions.

Results

Significant differences between participants with and without neck pain were found in different wrist positions, in neutral wrist position right [without neck pain (n = 48) 46.34 (43.39 - 49.30); with neck pain (n = 97) 38.46 (36.20 - 40.72), F _(1,144)  = 16.82, p < 0.001, ŋ _p ² = 0.11] and left [without neck pain 44.06 (41.19 - 46.94); with neck pain 37.36 (35.13 - 39.58), F _(1,144)  = 12.70, p < 0.001, ŋ _p ² = 0.08]. A significant difference between participants with and without wrist pain was found for neutral wrist position right [without wrist pain (n = 105) 42.53 (40.37 - 44.70); with wrist pain (n = 40) 37.24 (33.56 - 40.91), F _(1,144)  = 6.41, p = 0.01, ŋ _p ² = 0.04]. Regression analysis showed significant results especially for steps two (age and weight, NDI) and three (age and weight, NDI, Boston Carpal Tunnel Questionnaire) for neutral position right (R² = 0.355, R² = 0.357, respectively).

Conclusion

Neck pain has an impact on HGS but should be evaluated in consideration of age and sex.

The clinical experiences of Nigerian physiotherapists in managing environmental and socioeconomic determinants of mobility for older adults

Study Aim: To describe how physiotherapists in northern Nigeria managed the environmental and socioeconomic determinants of mobility for older adults.Methods: We adopted a qualitative description approach, purposely selected and conducted telephone interviews with 20 physiotherapists from Abuja [the Federal Capital Territory], four of the six states in North-central, and one state in the North-west regions of Nigeria. Data were analyzed using qualitative content and constant comparative analyses.Result: The physiotherapists had between 5 and 11 years practice experience in managing older adults with mobility limitations. Three iterative stages of identification, intervention, and documentation emerged as clinical experiences of Nigerian physiotherapists in managing environmental and socioeconomic determinants of mobility for older adults. Identification stages included determining older adults with mobility limitation through patients'/physiotherapists' reports and identifying the environmental (e.g. staircase location, floor types, furniture, and the urban built environment) and socioeconomic (e.g. education, income, and occupation) factors. The clinical decision of the "best" individualized approach to intervention, providing reassurance and education during and after the intervention were sub-stages for the intervention stage. There is a potential gap in the documentation process of these stages as most of the physiotherapists (n = 15; 75%) reported not doing so.Conclusion: This study suggested three iterative stages of identification, intervention, and documentation of the environmental and socioeconomic determinants of mobility for older adults. While there was a potential gap in regard to documentation of these stages in patients' case notes, physiotherapists especially in North-central Nigeria believed that co-developing a pragmatic set of clinical questions focusing on these determinants of mobility could encourage physiotherapists to explicitly document them. As the approach used in our research is purely descriptive, a grounded theory approach would potentially provide more detailed sub-stages that could be a more effective guide for physiotherapists to use during clinical practice.

Childhood socioeconomic disadvantage as a determinant of late-life physical function in older Japanese people

BACKGROUND

In this study, we examined the relationship between childhood socioeconomic status and physical function among older Japanese people, and investigated whether there is a sex variation in this association.

METHODS

We administered a cross-sectional questionnaire survey to all independent community-dwelling individuals ≥65 years old, living in Adachi Ward, Tokyo (N = 132,005). Participants self-reported their physical function using the Motor Fitness Scale, and we divided the scores into quartiles for analysis. Childhood socioeconomic status was retrospectively assessed according to a single item.

RESULTS

We analyzed 75,358 questionnaires. The average age of participants was 73.8 ± 6.0 years, and 55.0% were women. An ordered logistic regression analysis showed that lower childhood socioeconomic status was associated with lower physical function, independent of adult sociodemographic factors, health behaviors, and health conditions. This association was stronger in women than in men.

CONCLUSIONS

Our findings indicate that low childhood socioeconomic status might have a long-term influence on physical function in late life and that this influence varies by sex. Assessment of socioeconomic disadvantage in childhood is important for developing strategies to help older people maintain their physical function longer.

Influence of Manual Labor at Work on Muscular Fitness and Its Relationship With Work Performance

OBJECTIVE

The present study examined the influence of workplace manual labor on measures of muscular fitness, with a secondary aim to investigate the relationship between muscular fitness and work performance in blue-collar (BC) workers.

METHODS

Leg extension isokinetic strength at slow and fast velocities, hamstring and hip-flexor flexibility, and low back muscular endurance were examined in young and older BC workers and white-collar (WC) controls, while work performance was examined in the BC cohort.

RESULTS

There were no differences in muscular fitness variables between BC and WC groups; however, the older men had lower low back muscular endurance (-43.0%) and strength at slow (-9.4%) and fast (-12.7%) velocities. Work performance was associated with strength at fast velocities (r = 0.633) in the older BC workers.

CONCLUSIONS

Leg strength may influence work performance, with higher velocities becoming more important in older workers.

Links between Primary Occupation and Functional Limitations among Older Adults in Mexico

Social inequalities in health and disability are often attributed to differences in childhood adversity, access to care, health behavior, residential environments, stress, and the psychosocial aspects of work environments. Yet, disadvantaged people are also more likely to hold jobs requiring heavy physical labor, repetitive movement, ergonomic strain, and safety hazards. We investigate the role of physical work conditions in contributing to social inequality in mobility among older adults in Mexico, using data from the Mexican Health and Aging Survey (MHAS) and an innovative statistical modeling approach. We use data on categories of primary adult occupation to serve as proxies for jobs with more or less demanding physical work requirements. Our results show that more physically demanding jobs are associated with mobility limitations at older ages, even when we control for age and sex. Inclusion of job categories attenuates the effects of education and wealth on mobility limitations, suggesting that physical work conditions account for at least part of the socioeconomic differentials in mobility limitations in Mexico.

Frailty, prefrailty and employment outcomes in Health and Employment After Fifty (HEAF) Study

OBJECTIVES

Demographic changes are requiring people to work longer. No previous studies, however, have focused on whether the 'frailty' phenotype (which predicts adverse events in the elderly) is associated with employment difficulties. To provide information, we assessed associations in the Health and Employment After Fifty Study, a population-based cohort of 50-65-year olds.

METHODS

Subjects, who were recruited from 24 English general practices, completed a baseline questionnaire on 'prefrailty' and 'frailty' (adapted Fried criteria) and several work outcomes, including health-related job loss (HRJL), prolonged sickness absence (>20 days vs less, past 12 months), having to cut down substantially at work and difficulty coping with work's demands. Associations were assessed using logistic regression and population attributable fractions (PAFs) were calculated.

RESULTS

In all, 3.9% of 8095 respondents were classed as 'frail' and 31.6% as 'prefrail'. Three-quarters of the former were not in work, while 60% had left their last job on health grounds (OR for HRJL vs non-frail subjects, 30.0 (95% CI 23.0 to 39.2)). Among those in work, ORs for prolonged sickness absence, cutting down substantially at work and struggling with work's physical demands ranged from 10.7 to 17.2. The PAF for HRJL when any frailty marker was present was 51.8% and that for prolonged sickness absence was 32.5%. Associations were strongest with slow reported walking speed. Several associations were stronger in manual workers than in managers.

CONCLUSIONS

Fried frailty symptoms are not uncommon in mid-life and are strongly linked with economically important adverse employment outcomes. Frailty could represent an important target for prevention.

Occupational differences for nutrient intake and physical-activity levels in young and middle-aged men

BACKGROUND

Physical demands may vary between white collar and blue collar occupations when evaluating specific physiological differences such as one's weight, body mass index and body fat percentage.

OBJECTIVE

To explore nutritional, anthropometric, and physical-activity differences between young and middle-aged WC and BC workers.

METHODS

Ninety-one male participants aged 19-64 that were either WC and/or BC workers completed a 3-day food recall, modified Baecke Questionnaire, and had their height, weight, body mass index and body fat percentage measured. Participants were classified as: young-white-collar, young-blue-collar, middle-white-collar or middle-blue-collar workers.

RESULTS

No nutritional differences within ages or between occupations were reported. Body mass index and body fat percentage were lower for young vs. middle-aged workers. Lastly, physical-activity at work was higher for young and middle-aged Blue collar workers, while White collar workers participated in more physical activity outside of work.

CONCLUSIONS

The present findings suggest that the observed increases in body fat percentage and body mass index with age, are independent of occupation.

Late-life deficits in cognitive, physical and emotional functions, childhood intelligence and occupational profile: a life-course examination of the Aberdeen 1936 Birth Cohort (ABC1936)

OBJECTIVES

the 'triad of impairment' phenomenon describes the co-occurrence of age-related cognitive, emotional and physical functioning deficits. We investigated how occupational profile and childhood intelligence contribute to the triad of impairment in late life.

METHODS

we analysed data of a subsample of the Aberdeen Birth Cohort of 1936 (n = 346). Data were collected on participants' childhood intelligence, late-life cognitive ability, physical functioning, depressive symptoms and main lifetime occupation. We summarised the various occupational and impairment measures into two latent variables, 'occupational profile' and the 'triad of impairment'. We used a series of data reduction approaches and structural equation models (SEMs) of increasing complexity to test both the validity of the models and to understand causal relationships between the life-course risks for the triad of impairment.

RESULTS

occupational profile had a significant effect on the triad of impairment independent of childhood intelligence. Childhood intelligence was the predominant influence on the triad of impairment and exerted its effect directly and indirectly via its influence on occupation. The direct effect of childhood intelligence exceeded the independent influence of the occupational profile on impairment by a factor of 1.7-1.8 and was greater by a factor of ∼4 from the indirect pathway (via occupation).

CONCLUSIONS

childhood intelligence was the predominant influence on the triad of impairment in late life, independently of the occupational profile. Efforts to reduce impairment in older adults should be informed by a life-course approach with special attention to the early-life environment.

The Association of Levels of and Decline in Grip Strength in Old Age with Trajectories of Life Course Occupational Position

Background

The study of the influence of life course occupational position (OP) on health in old age demands analysis of time patterns in both OP and health. We study associations between life course time patterns of OP and decline in grip strength in old age.

Methods

We analyze 5 waves from the Survey of Health Ageing and Retirement in Europe (n = 5108, ages 65–90). We use a pattern-mixture latent growth model to predict the level and decline in grip strength in old age by trajectory of life course OP. We extend and generalize the structured regression approach to establish the explanatory power of different life course models for both the level and decline of grip strength.

Results

Grip strength declined linearly by 0.70 kg (95% CI -0.74;-0.66) for men and 0.42 kg (95% CI -0.45;-0.39) for women per year. The level of men’s grip strength can best be explained by a critical period during midlife, with those exposed to low OP during this period having 1.67 kg (95% CI -2.33;-1.00) less grip strength. These differences remain constant over age. For women, no association between OP and levels of or decline in grip strength was found.

Conclusions

Men’s OP in midlife seems to be a critical period for the level of grip strength in old age. Inequalities remain constant over age. The integration of the structured regression approach and latent growth modelling offers new possibilities for life course epidemiology.

Midlife Occupational Physical Activity and Risk of Disability Later in Life: National Health and Aging Trends Study

OBJECTIVES

To determine whether midlife occupational physical activity (PA) is associated with disability in older adults and to test disease as a mediating variable.

DESIGN

Cross-sectional study.

SETTING

National Health and Aging Trends Study.

PARTICIPANTS

Individuals aged 65 and older (N = 7,307).

MEASUREMENTS

Participants were classified as to occupational PA levels by linking information from the Occupational Information Network database using standard occupation codes. Disability outcomes and covariates were obtained through in-person interviews. Logistic regression models were used to examine the association between occupational PA and disability. Structural equation modeling (SEM) was fitted to examine the mediating effect of disease.

RESULTS

Occupations with high physically demands were associated with greater decline in functional capacity later in life. Individuals with occupations with high and very high PA were less likely to be able to perform activities of daily living than those with occupations with low PA. SEM showed that occupational PA has a very strong direct effect on disability (P < .001) and has an indirect effect on disability through disease (P = .003). The population attributable fraction for high occupational PA was 11%.

CONCLUSION

Higher midlife occupational PA levels were significantly associated with poorer ability to perform activities of daily living in older age. Performing the optimal level of occupational PA may be instrumental in reducing disability later in life.

Socioeconomic disparities in gait speed and associated characteristics in early old age

Background

A few studies have documented associations between socioeconomic position and gait speed, but the knowledge about factors from various domains (personal factors, lifestyle, occupation…) which contribute to these disparities is limited. Our objective was to assess socioeconomic disparities in usual gait speed in a general population in early old age in France, and to identify potential contributors to the observed disparities, including occupational factors.

Methods

The study population comprised 397 men and 339 women, aged 55 to 69, recruited throughout France for the field pilot of the CONSTANCES cohort. Gait speed was measured in meters/second. Socioeconomic position was based on self-reported occupational class. Information on personal characteristics, lifestyle, comorbidities and past or current occupational physical exposure came either from the health examination, from interview or from self-administered questionnaire. Four groups were considered according to sex-specific distributions of speed (the two slowest thirds versus the fastest third, for each gender). Logistic regression models adjusted for health screening center and age allowed to the study of cross-sectional associations between: 1- slower speed and occupational class; 2- slower speed and each potential contributor; 3- occupational class and selected potential contributors. The association between speed and occupational class was then further adjusted for the factors significantly associated both with speed and occupational class, in order to assess the potential contribution of these factors to disparities.

Results

With reference to managers/executives, gait speed was reduced in less skilled categories among men (OR 1.21 [0.72–2.05] for Intermediate/Tradesmen, 1.95 [0.80–4.76] for Clerks, Sale/service workers, 2.09 [1.14–3.82] for Blue collar/Craftsmen) and among women (OR 1.12 [0.55–2.28] for Intermediate/Tradesmen, 2.33 [1.09–4.97] for Clerks, 2.48 [1.18–5.24] for Sale/service workers/Blue collar/Craftsmen). Among men, occupational exposure to carrying heavy loads explained a large part of socioeconomic disparities. Among women, obesity and occupational exposure to repetitive work contributed independently to the disparities.

Conclusions

This study suggests that some potentially modifiable occupational and personal factors explain at least part of the differences in gait speed between occupational classes, and that these factors differ between men and women. Longitudinal studies are needed to confirm and complement these findings.

Heavy manual work throughout the working lifetime and muscle strength among men at retirement age

INTRODUCTION

Reductions in heavy manual work as a consequence of mechanisation might adversely impact muscle strength at older ages. We investigated the association between grip strength at retirement age and lifetime occupational exposure to physically demanding activities. Grip strength is an important predictor of long-term health and physical function in older people.

METHODS

Grip strength (maximum of three readings in each hand) was measured in men from the Hertfordshire Cohort Study at a single examination when their mean age was 65.8 (SD 2.9) years. Associations with lifetime occupational exposure (ascertained by questionnaire) to three activities (standing/walking ≥ 4 h/day; lifting ≥ 25 kg; and energetic work sufficient to induce sweating) were assessed by multivariable linear regression with adjustment for various potential confounders.

RESULTS

Complete data were available from 1418 men who had worked for at least 20 years. After adjustment for age, height and weight, those with longer exposures to walking/standing and heavy lifting had lower grip strength, but the relationship disappeared after further adjustment for confounders. Working at physical intensity sufficient to induce sweating was not significantly associated with grip strength.

CONCLUSIONS

We found no evidence that physically demanding occupational activities increase hand grip strength at normal retirement age. Any advantages of regular physical occupational activity may have been obscured by unmeasured socioeconomic confounders.

Heavy Physical Work: Cardiovascular Load in Male Construction Workers

This study aimed to elucidate cardiovascular loads (CVL) in construction workers during work and leisure by relative heart rate (RHR) over several days. Furthermore, we sought to evaluate the level of CVL in relation to individual factors, work ability, musculoskeletal pain and subjective general health. From a group of 255 construction workers responding to the baseline questionnaire, the CVL during work and leisure time was determined by recording RHR in 42 workers over 3–4 days. Almost 60% of the workday was spent below 20% RHR. The mean RHR during work for all participants was 16% RHR, with large differences between professions. On average, the 42 workers spent 14% of the workday at a RHR above 33%, and four subjects (10%) had a mean RHR above 33% during work. Eight (19%) of the participants had a mean length of their workday exceeding calculated maximal acceptable work time. Seven persons (17%) experienced on average one or more episode(s) of 5 min or more continuously above 33% RHR. The cardiovascular load at work was significantly associated with age and V˙O_2max, but not with work ability, musculoskeletal pain or subjective general health.

Does physical exposure throughout working life influence chair-rise performance in midlife? A retrospective cohort study of associations between work and physical function in Denmark

OBJECTIVES

Our aim was to study associations between physical exposures throughout working life and physical function measured as chair-rise performance in midlife.

METHODS

The Copenhagen Aging and Midlife Biobank (CAMB) provided data about employment and measures of physical function. Individual job histories were assigned exposures from a job exposure matrix. Exposures were standardised to ton-years (lifting 1000 kg each day in 1 year), stand-years (standing/walking for 6 h each day in 1 year) and kneel-years (kneeling for 1 h each day in 1 year). The associations between exposure-years and chair-rise performance (number of chair-rises in 30 s) were analysed in multivariate linear and non-linear regression models adjusted for covariates.

RESULTS

Mean age among the 5095 participants was 59 years in both genders, and, on average, men achieved 21.58 (SD=5.60) and women 20.38 (SD=5.33) chair-rises in 30 s. Physical exposures were associated with poorer chair-rise performance in both men and women, however, only associations between lifting and standing/walking and chair-rise remained statistically significant among men in the final model. Spline regression analyses showed non-linear associations and confirmed the findings.

CONCLUSIONS

Higher physical exposure throughout working life is associated with slightly poorer chair-rise performance. The associations between exposure and outcome were non-linear.

The influence of occupation and age on maximal and rapid lower extremity strength

The aims of this study were to 1) examine the influence of age and occupation on maximal and rapid strength of the lower-extremity muscles and 2) examine the relationship between maximal and rapid strength and physical workload (work index (WI)) in the blue-collar (BC) cohort. Peak torque (PT) and peak rate of torque development (peakRTD) of the leg extensors (LE), leg flexors (LF), and plantar flexors (PF) were assessed in 47 young (age = 24.1 ± 2.4 years) and 41 middle-aged (52.4 ± 5.2 years) white-collar (WC) and BC men. Middle-aged workers exhibited lower PT for all muscles, and peakRTD for the LF and PF muscles. A positive relationship (r = 0.59; P < 0.01) was observed between WI and peakRTD for the PF in the young BC workers, however, this relationship was negative (r = -0.45; P = 0.053) for the LF of the middle-aged BC workers. Lowering physical work demands and/or incorporating effective health-related practices for employees may be appealing strategies to enhance aging workers' productivity and longevity in the workforce.

Association between hand-grip strength and depressive symptoms: Locomotive Syndrome and Health Outcomes in Aizu Cohort Study (LOHAS)

BACKGROUND

no study has examined the longitudinal association between hand-grip strength and mental health, such as depressive symptoms.

OBJECTIVE

we investigated the relationship between baseline hand-grip strength and the risk of depressive symptoms.

DESIGN

a prospective cohort study.

SETTING AND SUBJECTS

a prospective cohort study with a 1-year follow-up was conducted using 4,314 subjects from community-dwelling individuals aged 40-79 years in two Japanese municipalities, based on the Locomotive Syndrome and Health Outcomes in Aizu Cohort Study (LOHAS, 2008-10).

METHODS

we assessed baseline hand-grip strength standardised using national representative data classified by age and gender, and depressive symptoms at baseline and after the follow-up using the five-item version of the Mental Health Inventory (MHI-5).

RESULTS

the 4,314 subjects had a mean age of 66.3 years, 58.5% were women, and mean unadjusted hand-grip strength was 29.8 kg. Multivariable random-effect logistic regression analysis revealed that subjects with lower hand-grip strength (per 1SD decrease) had higher odds of having depressive symptoms at baseline [adjusted odds ratio (AOR) 1.15, 95% confidence interval (CI) 1.06-1.24; P = 0.001]. Further, lower hand-grip strength (per 1SD decrease) was associated with the longitudinal development of depressive symptoms after 1 year (AOR 1.13, 95% CI 1.01-1.27; P = 0.036).

CONCLUSIONS

using a large population-based sample, our results suggest that lower hand-grip strength, standardised using age and gender, is both cross-sectionally and longitudinally associated with depressive symptoms.

Occupational physical demand and risk of hip fracture in older women

OBJECTIVES

Hip fractures are leading causes of disability, morbidity and mortality among older women. Since physical activity helps maintain physical functioning and bone mineral density, occupational physical demand may influence fracture risk. This study investigates the association of occupational physical demand with hip fracture incidence among women.

METHODS

The Women's Health Initiative Observational Study is a multiethnic cohort of 93,676 postmenopausal women, 50-79 years of age at enrolment, enrolled from 1994 to 1998 at 40 geographically diverse clinical centres throughout the USA. Outcomes including hip fractures were assessed annually and up to 3 jobs held since age 18 years were reported by each woman. Occupational physical demand levels were assigned for each job through linkage of occupational titles with Standard Occupational Codes and the Occupational Information Network. Average, cumulative and peak physical demand scores both before and after menopause and throughout women's work life were estimated.

RESULTS

Women were followed through 2010 for an average of 11.5 years; 1834 hip fractures occurred during this time. We did not observe an overall association of occupational physical demand with subsequent risk of hip fracture after adjusting for age, race/ethnicity, birth region and education.

CONCLUSIONS

Previous research on occupations and hip fracture risk in women is inconclusive. This study was able to take critical risk periods into account and control for confounding factors in a large cohort of older women to show that overall occupational physical demand neither increases nor decreases risk of hip fracture later in life.

The impact of occupational experience on cognitive and physical functional status among older adults in a representative sample of Korean subjects

OBJECTIVE

This study investigated the impact of occupation on cognitive and physical function within an occupational window of the past 15 years using a nationally representative sample in Korea.

METHODS

A total of 4,408 subjects aged 60 and older were selected from the Korean Longitudinal Study of Aging (KLoSA). Functional health was evaluated using the Korean versions of the Mental State Examination (K-MMSE), Instrumental Activities of Daily Living (K-IADL), and Activities of Daily Living (K-ADL) measures.

RESULTS

The prevalence of lower function was higher among women than among men, and employed persons had better cognitive and physical function compared with the retired and unemployed. Longer work duration during the past 15 years significantly and positively affected all measures of function in men, whereas it only improved physical function in women. Manual laborers exhibited improved functional capacity with longer work durations over the past 15 years, although they presented lower functional scores compared with non-manual laborers. There was a curvilinear relationship of work duration with cognitive and physical function among men and manual laborers.

CONCLUSION

In our population, longer work duration, especially for men and for manual laborers, appears to be a significant contributor to the cognitive and physical function of older people.

Dietary protein intake is associated with maximal and explosive strength of the leg flexors in young and older blue collar workers

The aim of this study was to investigate the association between dietary protein (PRO) intake and maximal and rapid strength of the leg flexors in blue collar (BC) working men. Twenty-four young (age, 23.2 ± 2.1 years) and 19 older (age, 52.8 ± 5.2 years) men employed in BC occupations completed a 3-day dietary record and isometric strength testing of the leg flexors. Food logs were analyzed for total PRO (TPRO) and essential amino acid (EAA) intake. Rapid and maximal strength capacities were examined from the rate of torque development at 50 milliseconds and peak torque of the torque-time curves, respectively. Pearson correlations and partial correlations were used to examine the relationships between TPRO and EAA intake on strength variables. Peak torque was positively correlated to TPRO and EAA intake in the young (r = 0.439 and r = 0.431; P < .05) and older (r = 0.636 and r = 0.605; P < .01) men, and rate of torque development at 50 milliseconds was correlated to TPRO and EAA intake in the young (r = 0.512 and r = 0.310; P = .01) and older (r = 0.662 and r = 0.665; P < .01) men, respectively. There were no relationships (P > .05) between TPRO and strength variables when controlling for EAA intake. Total PRO intake explained 20 to 44% of the variance in rapid and maximal strength for both age groups. Essential amino acid intake was largely responsible for the positive relationship between PRO intake and strength. Across young and older BC working male populations, PRO consumption was associated with both maximal and explosive strength capacities of the leg flexors muscle group.

The role of partnership status on late-life physical function

This study examined the socioeconomic pathways linking partnership status to physical functioning, assessed using objective measures of late life physical functioning, including peak flow and grip strength. Using Wave 4 of the Survey of Health, Ageing and Retirement in Europe (SHARE), we ran multilevel models to examine the relationship between partnership status and physical function in late life, adjusting for social-network characteristics, socioeconomic factors, and health behaviours. We found a robust relationship between partnership status and physical function. Incorporating social-network characteristics, socioeconomic factors, and health behaviours showed independent robust relationships with physical function. Co-variates attenuated the impact of cohabitation, separation, and widowhood on physical function; robust effects were found for singlehood and divorce. Sex-segregated analyses suggest that associations between cohabitation, singlehood, divorce, and widowhood were larger for men than for women. Results suggest that social ties are important to improved physical function.

Musculoskeletal health and work ability in physically demanding occupations: study protocol for a prospective field study on construction and health care workers

BACKGROUND

Musculoskeletal disorders have a profound impact on individual health, sickness absence and early retirement, particularly in physically demanding occupations. Demographics are changing in the developed countries, towards increasing proportions of senior workers. These senior workers may have particular difficulties coping with physically demanding occupations while maintaining good health. Previous studies investigating the relationship between physical work demands and musculoskeletal disorders are mainly based on self-reported exposures and lack a prospective design. The aim of this paper is to describe the background and methods and discuss challenges for a field study examining physical demands in construction and health care work and their prospective associations with musculoskeletal disorders, work ability and sickness absence.

METHODS AND DESIGN

This protocol describes a prospective cohort study on 1200 construction and health care workers. Participants will answer a baseline questionnaire concerning musculoskeletal complaints, general health, psychosocial and organizational factors at work, work demands, work ability and physical activity during leisure. A shorter questionnaire will be answered every 6th months for a total of two years, together with continuous sickness absence monitoring during this period. Analysis will prospectively consider associations between self-reported physical demands and musculoskeletal disorders, work ability and sickness absence. To obtain objective data on physical exposures, technical measurements will be collected from two subgroups of N = 300 (Group A) and N = 160 (Group B) during work and leisure. Both group A and B will be given a physical health examination, be tested for physical capacity and physical activity will be measured for four days. Additionally, muscle activity, ground reaction force, body positions and physical activity will be examined during one workday for Group B. Analysis of associations between objectively measured exposure data and the outcomes described above will be done separately for these subpopulations.

DISCUSSION

The field study will at baseline produce objectively measured data on physical demands in the construction and health care occupations. In combination with clinical measurements and questionnaire data during follow-up, this will provide a solid foundation to prospectively investigate relationships between physical demands at work and development of musculoskeletal disorders, work ability and sickness absence.

Immediate and delayed effects of forearm kinesio taping on grip strength

BACKGROUND

Due to the fundamental role of gripping in most upper limb activities, grip strength promotion is a chief goal in the treatment of patients with upper limb musculoskeletal disorders. Kinesio taping is a novel and effective therapeutic technique believed to facilitate muscle contraction through stimulating mechanoreceptors and increasing the sensory feedback around the taped region.

OBJECTIVES

The present study aimed to identify the best region (flexor, extensor and flexor/extensor regions) and time (immediate, 0.5, 1, 1.5, and 2 hours) of forearm Kinesio taping to obtain the maximum improvement in grip strength.

MATERIALS AND METHODS

In this longitudinal study, 40 healthy men and women (the mean age of 22.3 ± 2.19 years) were selected among students of Shahid Beheshti University of Medical Sciences, Tehran, Iran by simple, nonrandom sampling method. A dynamometer was used to measure grip strength immediately and every 30 minutes during the two hours after I-shaped application of tape (with 50% stretch) to the flexor, extensor, and flexor/extensor forearm muscles.

RESULTS

Grip strength was significantly increased in various muscle groups for males (P = 0.002) and females (P = 0.000) of the forearm and at different intervals for males (P = 0.000) and females (P = 0.000). Moreover, in both men and women, tape application to the extensor region provided greater grip strength compared to taping of the flexor and flexor/extensor regions (P = 0.000 for both). Furthermore, the maximum increase in grip strength were 0.5 (10.8% increase, P = 0.001) and 1.5 h (23.9% increase, P = 0.000) after taping in males and females, respectively.

CONCLUSIONS

Taping the extensor region of forearm is recommended to achieve higher grip strength. Although grip strength increased at a slower pace in females than males, the final values were higher in women.

Variation in work tasks in relation to pinch grip strength among middle-aged female dentists

OBJECTIVES

We aimed to investigate the relationship of task variation during dental work history with pinch grip strength among dentists.

METHODS

We measured pinch grip strength among 295 female Finnish dentists aged 45-63 years. Variation in dental work tasks during work history was empirically defined by cluster analysis. Three clusters of task variation emerged: low (most work time in restoration treatment/endodontics), moderate (about 50% in the former and 50% in prosthodontics/periodontics/surgery), and high (variable tasks including administrative duties). Hand radiographs were examined for the presence of OA in the wrist and each joint of the 1-3rd fingers. Information on hand-loading leisure-time activities, and joint pain was obtained by questionnaire. Glove size was used as a proxy for hand size. BMI (kg/m2) was based on measured weight and self-reported height.

RESULTS

Dentists with low variation of work task history had an increased risk of low pinch grip strength in the right hand (OR 2.3, 95% CI 1.2-4.3), but not in the left (1.13, 0.62-2.08), compared to dentists with high task variation, independent of age, hand size, hand-loading leisure-time activities, BMI and symptomatic hand OA.

CONCLUSION

The dentists with the most hand-loading tasks were at an increased risk of low pinch grip strength, independent of e.g. symptomatic hand OA. It is advisable among dentists to perform as diverse work tasks as possible to reduce the risk of decreased pinch grip strength.

Is midlife occupational physical activity related to disability in old age? The SNAC-Kungsholmen study

Objectives

Leisure-time physical activity (PA) has been established to be related to more years lived without disability. However, less is known about the relationship between occupational PA and disability in old age. The aim of the study was 1) to investigate whether midlife occupational PA is related to late-life disability, and 2) to test the hypothesis that the association differs according to the occupational categories of blue and white collar work.

Methods

The study population was derived from the Swedish National Study on Aging and Care, and consisted of a random sample of 1804 subjects aged 72 and above. The association of occupational PA during the longest held occupation with disability in old age was determined using logistic regression.

Results

There was no significant relationship between occupational PA and disability in personal or instrumental activities of daily living (ADL) after controlling for demographic and health-related factors. However, in stratified analyses moderate levels of occupational PA was associated with a lower odds ratio of dependency in personal ADL amongst white collar workers, compared to low level of occupational PA (OR = 0.34 95% C1 0.12–0.98).

Conclusions

Moderate levels of midlife occupational PA were associated with a decreased risk of personal ADL disability in old age among white collar workers, but not among blue collar workers. Our results highlight the importance of encouraging white collar workers to engage in physical activity during or outside work hours.

Education-related differences in physical performance after age 60: a cross-sectional study assessing variation by age, gender and occupation

Background

Having a low level of education has been associated with worse physical performance. However, it is unclear whether this association varies by age, gender or the occupational categories of manual and non-manual work. This study examined whether there are education-related differences across four dimensions of physical performance by age, gender or occupational class and to what extent chronic diseases and lifestyle-related factors may explain such differences.

Methods

Participants were a random sample of 3212 people, 60 years and older, both living in their own homes and in institutions, from the Swedish National Study on Aging and Care, in Kungsholmen, Stockholm. Trained nurses assessed physical performance in grip strength, walking speed, balance and chair stands, and gathered data on education, occupation and lifestyle-related factors, such as physical exercise, body mass index, smoking and alcohol consumption. Diagnoses of chronic diseases were made by the examining physician.

Results

Censored normal regression analyses showed that persons with university education had better grip strength, balance, chair stand time and walking speed than people with elementary school education. The differences in balance and walking speed remained statistically significant (p < 0.05) after adjustment for chronic diseases and lifestyle. However, age-stratified analyses revealed that the differences were no longer statistically significant in advanced age (80+ years). Gender-stratified analyses revealed that women with university education had significantly better grip strength, balance and walking speed compared to women with elementary school education and men with university education had significantly better chair stands and walking speed compared to men with elementary school education in multivariate adjusted models. Further analyses stratified by gender and occupational class suggested that the education-related difference in grip strength was only evident among female manual workers, while the difference in balance and walking speed was only evident among female and male non-manual workers, respectively.

Conclusions

Higher education was associated with better lower extremity performance in people aged 60 to 80, but not in advanced age (80+ years). Our results indicate that higher education is associated with better grip strength among female manual workers and with better balance and walking speed among female and male non-manual workers, respectively.

Motor function in the elderly: evidence for the reserve hypothesis

OBJECTIVE

The reserve hypothesis accounts for the lack of direct relationship between brain pathology and its clinical manifestations. Research has mostly focused on cognition; our objective is to examine whether the reserve hypothesis applies to motor function. We investigated whether education, a marker of reserve, modifies the association between white matter lesions (WMLs), a marker of vascular brain damage, and maximum walking speed (WS), an objective measure of motor function. We also examined the cross-sectional and longitudinal association between education and WS.

METHODS

Data are from 4,010 participants aged 65-85 years in the longitudinal Three-City-Dijon Study with up to 4 WS measures over 10 years. We examined the interaction between education and WMLs for baseline WS. We studied the association between education and repeated WS measures using linear mixed models, and the role of covariates in explaining the education-WS association.

RESULTS

Education was strongly associated with baseline WS; the difference in mean WS between the high and low education groups (0.145 m/s, 95% confidence interval = 0.125-0.165) was equivalent to 7.4 years of age. WMLs were associated with slow WS only in the low education group (p interaction = 0.026). WS declined significantly over time (-0.194 m/s/10 years, 95% confidence interval = -0.206, -0.182), but education did not influence rate of decline. Anthropometric characteristics, parental education, general health, and cognition had the strongest role in explaining the baseline education-WS association.

CONCLUSIONS

Participants with more education were less susceptible to WMLs' effect on motor function. Higher education was associated with better motor performances but not with motor decline. These results are consistent with the passive reserve hypothesis.

Social engagement, health, and changes in occupational status: analysis of the Korean Longitudinal Study of Ageing (KLoSA)

Background

We focused on whether changes in the occupational status of older male adults can be influenced by social engagement and health status measured at the baseline.

Methods

This study used a sample of the Korean Longitudinal Study of Aging (KLoSA), and the study population was restricted to 1.531 men who were aged 55 to 80 years at the 2006 baseline survey and participated in the second survey in 2008. Social engagement and health status, measured by the number of chronic diseases, grip strength, and depressive symptoms as well as covariates (age, marital status, educational level, and household income) were based on data from the 2006 baseline survey. Occupational engagement over the first and second survey was divided into four categories: ‘consistently employed’ (n = 892), ‘employed-unemployed’ (n = 152), ‘unemployed-employed’ (n = 138), and ‘consistently unemployed’ (n = 349).

Results

In the multinomial model, the ‘consistently employed’ and ‘unemployed-employed’ groups had significantly higher social engagement (1.19 and 1.32 times, respectively) than the referent. The number of chronic diseases was significantly associated with four occupational changes, and the ‘unemployed-employed’ had the fewest chronic conditions.

Conclusion

Our finding suggests that social engagement and health status are likely to affect opportunities to continue working or to start working for older male adults.

Lifetime occupational physical activity and musculoskeletal aging in middle-aged men and women in denmark: retrospective cohort study protocol and methods

Background

Physical function is essential for performing most aspects of daily life and musculoskeletal aging leads to a decline in physical function. The onset and rate of this process vary and are influenced by environmental, genetic, and hormonal factors. Although everyone eventually experiences musculoskeletal aging, it is beneficial to study the factors that influence the aging process in order to prevent disability. The role of occupational physical activity in the musculoskeletal aging process is unclear. In the past, hard physical work was thought to strengthen the worker, but current studies in this field fail to find a training effect in jobs with a high level of occupational physical activity.

Objective

The aim of this study is to examine the influence of lifetime occupational physical activity on physical function in midlife. The study follows the “occupational life-course perspective,” emphasizing the importance of occupational exposures accumulated throughout life on the musculoskeletal aging process taking socioeconomic and lifestyle factors into consideration.

Methods

This study is a retrospective cohort study including a cross-sectional measurement of physical function in 5000 middle-aged Danes. Data was obtained from the Copenhagen Aging and Midlife Biobank (CAMB) which is based on three existing Danish cohorts. Using questionnaire information about the five longest-held occupations, the job history was coded from the Danish version of the International Standard Classification of Occupations (D-ISCO 88) and a job exposure matrix containing information about occupational physical activity in Danish jobs was applied to the dataset. The primary outcomes are three tests of physical function: handgrip strength, balance, and chair rise. In the analyses, we will compare physical function in midlife according to accumulated exposure to high levels of occupational physical activity.

Conclusions

We have a unique opportunity to study the influence of work on early musculoskeletal aging taking other factors into account. In this study, the “healthy worker effect” is reduced due to inclusion of people from the working population and people who are already retired or have been excluded from the labor market. However, low participation in the physical tests can lead to selection bias.

Risk factors for ischaemic heart disease mortality among men with different occupational physical demands. A 30-year prospective cohort study

Objectives Men with high physical work demands have elevated cardiovascular strain, which may lead to enhanced atherosclerosis. Theoretically, the impact of risk factors for ischaemic heart disease (IHD) may thus depend on physical work demands. The authors investigated this hypothesis. Design Prospective 30-year follow-up. Setting The Copenhagen Male Study. Participants 5249 gainfully employed men aged 40-59 years; 311 men with cardiovascular disease/diabetes were excluded. Primary and secondary outcome measures IHD and all-cause mortality. Results 579 men (11.8%) died due to IHD and 2628 (53.7%) from all-cause mortality. Similarities and differences in risk predictors were found between men with low (n=1219), medium (n=2636) and high (n=846) physical work demands. After control for potential confounders, high physical fitness conferred a reduced risk of IHD mortality only among men with high physical work demands (HR: 0.48, 95% CI 0.24 to 0.96), a moderate/high level of leisure-time physical activity was associated with reduced risk of IHD mortality only among men with moderate and high physical work demands. High systolic blood pressure and smoking were risk factors in all groups. Similar, but less pronounced differences in risk factors for all-cause mortality between groups were found. Conclusions The risk factors for IHD and all-cause mortality, low physical fitness and low leisure-time physical activity are not identical for men with different physical work demands. Preventive initiatives for IHD should be tailored to the physical work demands.

Predictors of Handgrip Strength among the Free Living Elderly in Rural Pahang, Malaysia

BACKGROUND

Reduced handgrip strength is an aging process that significantly influences the living activities of elderly. It is linked to premature mortality, disability and other health complications among elderly. Therefore, we aim to determine the associated predictors with handgrip strength among the free living elderly in Malaysia.

METHODS

This was a cross sectional study conducted in a rural state in Malaysia. A total of 434 elderly individuals performed handgrip assessment. Socio-demographic characteristics, medical conditions, occupational history, functional ability (ADL) and depression (GDS) were enquired. Anthropometric measurements (weight and height) were also obtained.

RESULTS

Majority of the respondents were Malays with mean age of 67.9 ± 6.3 years. Maximum handgrip strength of males and females were 28.8±9.2 kg and 18.9±6.9 kg respectively (P<0.05). The aborigines had significantly lower handgrip strength (P<0.05) compared to Malays, Chinese and Indians. Handgrip strength was positively correlated (P<0.05) with weight, height and ADL, while negatively associated (P<0.05) with GDS for both gender. In the multivariate linear regression analysis; weight, height and race significantly predicted handgrip strength among both male and female elderly after adjustment for all potential confounders. However, GDS and ADL were only found to significantly predict handgrip strength among the male elderly; while age was only significant among the females.

CONCLUSION

Our sample population has significantly lower handgrip strength than the Western counterpart. Weight, height and race significantly predict handgrip strength among both male and female elderly. GDS, ADL are only found to be significant in males while age was only significant among the females.

Socio-economic disadvantage from childhood to adulthood and locomotor function in old age: a lifecourse analysis of the Boyd Orr and Caerphilly prospective studies

BACKGROUND

Socio-economic influences over a lifetime impact on health and may contribute to poor physical functioning in old age.

METHODS

The authors examined the impact of both childhood and adulthood socio-economic factors on locomotor function at 63-86 years (measured with the get up and go timed walk and flamingo balance test) in the UK-based Boyd Orr (n=405) and Caerphilly (n=1196) prospective cohorts.

RESULTS

There was a marked reduction in walking speed and balance time with increasing age. Each year of age was associated with a 1.7% slower walk time and a 14% increased odds of poor balance. Participants who moved from a low socio-economic position in childhood to a high socio-economic position in adulthood had 3% slower walking times (95% CI -2% to 8%) than people with a high socio-economic position in both periods. Participants who moved from a high socio-economic position in childhood to a low adulthood socio-economic position had 5% slower walking times (95% CI -2% to 12%). Participants with a low socio-economic position in both periods had 10% slower walking times (95% CI 5% to 16%; p for trend <0.001). In Boyd Orr, low socio-economic position in childhood was associated with poor balance in old age (OR per worsening category=1.26; 95% CI 1.01 to 1.57; p=0.043), as was socio-economic position in adulthood (OR=1.71; 95% CI 1.20 to 2.45; p=0.003). Similar associations were not observed in Caerphilly.

CONCLUSION

Accumulating socio-economic disadvantage from childhood to adulthood is associated with slower walking time in old age, with mixed results for balance ability.

Lifelong socioeconomic position and physical performance in midlife: results from the British 1946 birth cohort

Socioeconomic position (SEP) across life is found to be related to adult physical performance, but the underlying pathways are not well characterized. Using a British birth cohort (N = 2956), the associations of SEP from childhood into midlife with objective physical performance measures in midlife were examined, adjusting for possible confounders or mediators, including indicators of muscle development and central nervous system function. Childhood and adulthood SEP were positively related to standing balance and chair rise performance, but not to grip strength after basic adjustments. When both father’s occupation and mother’s education were included in the same model, having a mother with low education was associated with 0.6 standard deviations (SD) (95% confidence interval (CI: 0.3, 0.8)) poorer standing balance time compared with having a mother with the highest educational level, and having a father in the lowest occupational group was associated with a 0.3 SD (95% CI: 0.1, 0.6) lower chair rise score compared with having a father in the highest occupational group. These associations were maintained, albeit attenuated, after adjustment. In contrast, the associations of own education and adult occupation with physical performance were generally not maintained after adjustment. SEP across life impacts on midlife physical performance, and thereby the ageing process.