Changes in physical performance according to job demands across three cohorts of older workers in the Longitudinal Aging Study Amsterdam.

This study set out to evaluate the association between job demands at baseline and physical performance over a six-year period across three cohorts of older Dutch workers examined 10 years apart. Data were drawn from three cohorts (1992-1999, 2002-2009 and 2012-2019) of the Longitudinal Aging Study Amsterdam. Individuals aged 55-65 years from each cohort who worked for pay were included (n = 274, n = 416, n = 618, respectively). Physical performance was measured using gait speed and chair stand performance. A population-based job exposure matrix was used to indicate levels of exposure probability of physical (use of force and repetitive movements) and psychosocial (cognitive demands and time pressure) job demands. We found that psychosocial job demands increased and physical demands decreased across the three cohorts. No between cohort differences were found for how job demands affected changes in physical performance over follow-up. For men, faster decline in gait speed was observed when comparing higher and lower use of force at baseline (ß -0.012, 95% CI -0.021, -0.004). Greater use of force and repetitive movements were associated with faster decline in chair stand performance (ß -0.012, 95% CI -0.020, -0.004 and ß -0.009, 95% CI -0.017, -0.001, respectively). In women, no association of job demands on change in physical performance was observed. The study concluded that higher physical job demands were associated with stronger decline in physical performance across six years for men in all cohorts, while no associations were found among women.

Impact or No Impact for Women With Mild Knee Osteoarthritis: A Bayesian Meta-Analysis of Two Randomized Controlled Trials With Contrasting Interventions.

OBJECTIVE: To predict the probability of a benefit from 2 contrasting exercise programs for women with a new diagnosis of mild knee osteoarthritis, and to estimate the short- and long-term effects of aquatic resistance training (ART) and high-impact aerobic land training (HLT) compared with a control. METHODS: Original data sets from 2 previously conducted randomized controlled trials were combined and used in a Bayesian meta-analysis. Group differences in multiple response variables were estimated. Variables included cardiorespiratory fitness, dynamic maximum leg muscle power, maximal isometric knee extension and flexion force, pain, other symptoms, and quality of life. The statistical model included a latent commitment variable for each female participant. RESULTS: ART had a 55-71% probability of benefits in the outcome variables, and as the main effect, the intervention outperformed the control in cardiorespiratory fitness, with a probability of 71% immediately after the intervention period. HLT had a 46-63% probability of benefits after intervention with the outcome variables, but differently from ART; the positive effects of physical performance fade away during the follow-up period. Overall, the differences between groups were small, and the variation in the predictions between individuals was high. CONCLUSION: Both interventions had benefits, but ART has a slightly higher probability of long-term benefits on physical performance. Because of high individual variation and no clear advantage of one training method over the other, personal preferences should be considered in the selection of the exercise program to ensure highest commitment to training.

Birth cohort differences in cognitive performance in 75- and 80-year-olds: a comparison of two cohorts over 28 years.

OBJECTIVE: To evaluate cohort differences in cognitive performance in older men and women born and assessed 28 years apart. METHODS: Data in this study were drawn from two age-homogeneous cohorts measured in the same laboratory using the same standardized cognitive performance tests. Participants in the first cohort were born in 1910 and 1914 and assessed in 1989-1990 (Evergreen project, n = 500). Participants in the second cohort were born in 1938 or 1939 and 1942 or 1943 and assessed in 2017-2018 (Evergreen II, n = 726). Participants in both cohorts were assessed at age 75 and 80 years and were recruited from the population register. Cognitive performance was measured using the Digit Span test from the Wechsler Memory Scale (WMS), Digit Symbol test from the Wechsler Adult Intelligence Scale (WAIS) and phonemic Verbal Fluency test from the Schaie-Thurstone Adult Mental Abilities Test. Reaction time assessing motor and mental responses was measured with a simple finger movement task, followed by a complex finger movement task. T-tests were used to study cohort differences and linear regression models to study possible factors underlying differences. RESULTS: We found statistically significant cohort differences in all the cognitive performance tests, except for the digit span test and simple movement task in men, the later-born cohort performing better in all the measured outcomes. CONCLUSIONS: The results of this study provide strong evidence that cognitive performance is better in more recent cohorts of older people compared to their counterparts measured 28 years earlier.

Cohort Differences in Maximal Physical Performance: A Comparison of 75- and 80-Year-Old Men and Women Born 28 Years Apart.

BACKGROUND: Whether increased life expectancy is accompanied by increased functional capacity in older people at specific ages is unclear. We compared similar validated measures of maximal physical performance in 2 population-based older cohorts born and assessed 28 years apart. METHOD: Participants in the first cohort were born in 1910 and 1914 and were assessed at age 75 and 80 years, respectively (N = 500, participation rate 77%). Participants in the second cohort were born in 1938 or 1939 and 1942 or 1943 and were assessed at age 75 and 80 years, respectively (N = 726, participation rate 40%). Participants were recruited using a population register and all community-dwelling persons in the target area were eligible. Both cohorts were interviewed at home and were examined at the research center with identical protocols. Maximal walking speed, maximal isometric grip and knee extension strength, forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) were assessed. Data on non-participation were systematically collected. RESULTS: Walking speed was on average 0.2-0.4 m/s faster in the later than earlier cohort. In grip strength, the improvements were 5%-25%, and in knee extension strength 20%-47%. In FVC, the improvements were 14-21% and in FEV1, 0-14%. CONCLUSIONS: The later cohort showed markedly and meaningfully higher results in the maximal functional capacity tests, suggesting that currently 75- and 80-year-old people in Finland are living to older ages nowadays with better physical functioning.

Effects of progressive aquatic resistance training on symptoms and quality of life in women with knee osteoarthritis: A secondary analysis.

OBJECTIVE: To conduct a secondary analysis to study the effects, those 4 months of aquatic resistance training have on self-assessed symptoms and quality of life in post-menopausal women with mild knee osteoarthritis (OA), after the intervention and after a 12-month follow-up period. METHODS: A total of 87 post-menopausal volunteer women, aged 60-68 years, with mild knee OA were recruited in a randomized, controlled, 4-month aquatic training trial (RCT) and randomly assigned to an intervention (n = 43) and a control (n = 44) group. The intervention group participated in 48 supervised aquatic resistance training sessions over 4 months while the control group maintained their usual level of physical activity. Additionally, 77 participants completed the 12-month post-intervention follow-up period. Self-assessed symptoms were estimated using the OA-specific Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and Health-related Quality of life (HRQoL) using the generic Short-form Health Survey (SF-36). RESULTS: After 4 months of aquatic resistance training, there was a significant decrease in the stiffness dimension of WOMAC -8.5 mm (95% CI = -14.9 to -2.0, P = .006) in the training group compared to the controls. After the cessation of the training, this benefit was no longer observed during the 12-month follow-up. No between-group differences were observed in any of the SF-36 dimensions. CONCLUSIONS: The results of this study show that participation in an intensive aquatic resistance training program did not have any short- or long-term impact on pain and physical function or quality of life in women with mild knee OA. However, a small short-term decrease in knee stiffness was observed.

Physical Activity Is Related with Cartilage Quality in Women with Knee Osteoarthritis.

PURPOSE: To study the relationship between 12-month leisure-time physical activity (LTPA) level and changes in estimated biochemical composition of tibiofemoral cartilage in postmenopausal women with mild knee osteoarthritis (OA). METHODS: Originally, 87 volunteer postmenopausal women, age 60 to 68 yr, with mild knee OA (Kellgren Lawrence I/II and knee pain) participated in a randomized controlled, 4-month aquatic training trial (RCT), after which 76 completed the 12-month postintervention follow-up period. Self-reported LTPA was collected along the 12-month period using a diary from which MET task hours per month were calculated. Participants were divided into MET task hour tertiles: 1, lowest (n = 25); 2 = middle (n = 25) and 3 = highest (n = 26). The biochemical composition of the cartilage was estimated using transverse relaxation time (T2) mapping sensitive to the properties of the collagen network and delayed gadolinium-enhanced magnetic resonance imaging of the cartilage (dGEMRIC index) sensitive to the cartilage glycosaminoglycan content. Secondary outcomes were cardiorespiratory fitness, isometric knee extension and flexion force, and the knee injury and OA outcome questionnaire. RESULTS: During the 12-month follow-up period, there was a significant linear relationship between higher LTPA level and increased dGEMRIC index changes in the posterior region of interest (ROI) of the lateral (P = 0.003 for linearity) and medial (P = 0.006) femoral cartilage. Furthermore, these changes were seen in the posterior lateral femoral cartilage superficial (P = 0.004) and deep (P = 0.007) ROI and in the posterior medial superficial ROI (P < 0.001). There was no linear relationship between LTPA level and other measured variables. CONCLUSIONS: These results suggest that higher LTPA level is related to regional increases in estimated glycosaminoglycan content of tibiofemoral cartilage in postmenopausal women with mild knee OA as measured with dGEMRIC index during a 12-month period.

Effects of a progressive aquatic resistance exercise program on the biochemical composition and morphology of cartilage in women with mild knee osteoarthritis: protocol for a randomised controlled trial.

BACKGROUND: Symptoms associated with osteoarthritis of the knee result in decreased function, loss of working capacity and extensive social and medical costs. There is a need to investigate and develop effective interventions to minimise the impact of and even prevent the progression of osteoarthritis. Aquatic exercise has been shown to be effective at reducing the impact of osteoarthritis. The purpose of this article is to describe the rationale, design and intervention of a study investigating the effect of an aquatic resistance exercise intervention on cartilage in postmenopausal women with mild knee osteoarthritis. METHODS: A minimum of 80 volunteers who meet the inclusion criteria will be recruited from the local population through newspaper advertisements. Following initial assessment volunteers will be randomised into two groups. The intervention group will participate in a progressive aquatic resistance exercise program of 1-hour duration 3 times a week for four months. The control group will be asked to maintain normal care during this period. Primary outcome measure for this study is the biochemical composition of knee cartilage measured using quantitative magnetic resonance imaging; T2 relaxation time and delayed gadolinium-enhanced magnetic resonance imaging techniques. In addition, knee cartilage morphology as regional cartilage thickness will be studied. Secondary outcomes include measures of body composition and bone traits using dual energy x-ray absorptiometry and peripheral quantitative computed tomography, pain, function using questionnaires and physical performance tests and quality of life. Measurements will be performed at baseline, after the 4-month intervention period and at one year follow up. DISCUSSION: This randomised controlled trial will investigate the effect a progressive aquatic resistance exercise program has on the biochemical composition of cartilage in post-menopausal women with mild knee osteoarthritis. This is the first study to investigate what impact aquatic exercise has on human articular cartilage. In addition it will investigate the effect aquatic exercise has on physical function, pain, bone and body composition and quality of life. The results of this study will help optimise the prescription of aquatic exercise to persons with mild knee osteoarthritis. TRIAL REGISTRATION: ISRCTN65346593.