Reaching forward: effects of a preceding task and aging

Successful Aging and Subjective Aging: Toward a Framework to Research a Neglected Connection

Research related to subjective aging, which describes how individuals perceive, interpret, and evaluate their own aging, has substantially grown in the past 2 decades. Evidence from longitudinal studies shows that subjective aging predicts health, quality of life, and functioning in later life. However, the existing literature on successful aging has mostly neglected the role of subjective aging. This paper proposes an extended framework of successful aging linking subjective aging conceptually and empirically to Rowe and Kahn's ((1997). Successful aging. Gerontologist, 37(4), 433-440) 3 original key criteria of successful aging (i.e., avoiding disease and disability, maintaining high cognitive and physical function, and engagement with life). A particular focus is placed on subjective aging as an antecedent of successful aging. A review of the empirical subjective aging literature shows that subjective aging concepts consistently predict all 3 of Rowe and Kahn's criteria of successful aging. Mechanisms underlying these relations are discussed at 3 levels, namely psychological, behavioral, and physiological pathways. The proposed addition also takes into consideration the interconnections between subjective aging and successful aging throughout the life span and across historical time. Finally, we discuss the importance of facilitating successful aging through systematic interventions that support more positive views of aging at the individual and societal levels.

The Effects of Graded Levels of Calorie Restriction: XX. Impact of Long-Term Graded Calorie Restriction on Survival and Body Mass Dynamics in Male C57BL/6J Mice

Calorie restriction (CR) typically promotes a reduction in body mass, which correlates with increased lifespan. We evaluated the overall changes in survival, body mass dynamics, and body composition following long-term graded CR (580 days/19 months) in male C57BL/6J mice. Control mice (0% restriction) were fed ad libitum in the dark phase only (12-hour ad libitum [12AL]). CR groups were restricted by 10%-40% of their baseline food intake (10CR, 20CR, 30CR, and 40CR). Body mass was recorded daily, and body composition was measured at 8 time points. At 728 days/24 months, all surviving mice were culled. A gradation in survival rate over the CR groups was found. The pattern of body mass loss differed over the graded CR groups. Whereas the lower CR groups rapidly resumed an energy balance with no significant loss of fat or fat-free mass, changes in the 30 and 40CR groups were attributed to higher fat-free mass loss and protection of fat mass. Day-to-day changes in body mass were less variable under CR than for the 12AL group. There was no indication that body mass was influenced by external factors. Partial autocorrelation analysis examined the relationship between daily changes in body masses. A negative correlation between mass on Day 0 and Day +1 declined with age in the 12AL but not the CR groups. A reduction in the correlation with age suggested body mass homeostasis is a marker of aging that declines at the end of life and is protected by CR.

Perceived facial age and biochemical indicators of glycemia in adult men and women

Glycemia is linked with one of the key mechanisms underlying the aging process and inter-individual differences in biological age. Previous research showed that glucose level is linked with perceived age in elder individuals. This study aimed to verify if glycemia is related to perceived facial age in healthy adult individuals as interventions in younger and healthy cohorts are crucial for preventing the onset of age-related diseases. The study sample consisted of 116 healthy men of mean age 35.53 ± 3.54 years (29.95–44.29) and 163 healthy women of mean age 28.38 ± 2.40 (24.25–34.17) years. Glycemia was evaluated by fasting glucose, insulin, HOMA-IR, and glycated hemoglobin level. BMI, facial sexual dimorphism, estradiol, testosterone, and hsCRP levels were controlled. Perceived age was evaluated based on standardized facial photos in an online survey. Additionally perceived facial aging was calculated as a difference between perceived age and chronological age. No relationship between the levels of biochemical indicators of glycemia and perceived facial age or aging was found both in men and women, also when controlled for possible confounders. This study shows that perceived facial age in adult individuals is rather linked with body adiposity of sexual dimorphism but not with glycemic markers.

The impact of aging and reaching movements on grip stability control during manual precision tasks

Background

Operating an object by generating stable hand-grip force during static or dynamic posture control of the upper extremities simultaneously is an important daily activity. Older adults require different attentional resources during grip strength control and arm movements. However, the impact of aging and reaching movements on precise grip strength and stability control among older adults is not well understood. This study investigated the impact of aging and reaching movements on grip strength and stability control in both hands of the upper extremities.

Methods

Fifty healthy young adults (age: 28.8 ± 14.0 years) and 54 healthy older adults (73.6 ± 6.3 years) were recruited to perform isometric grip strength test at 20% maximal voluntary contraction as the target force during three manual precision tasks simultaneously: stationary task (without arm movements), forward-reach task, and backward-reach task. The average grip force (in kg) and coefficient of variation values (expressed as a percentage) during manual precision tasks were calculated to determine the quality of participants’ grip strength. The deviation error, absolute error, and force-stability index values were calculated to determine the strength control relative to the target force.

Results

For both the young and older groups, the force-stability index values in both hands were significantly higher during forward- and backward-reaching movements than in the stationary condition (p < 0.05). The older group exhibited a significantly lower hand-grip strength and stability of strength control in both hands than the young group (p < 0.05).

Conclusions

Aging and reaching task performance reduced the grip strength of participants and increased the variations in strength control of both hands relative to the target force, indicating that older adults exhibit poor grip strength and stability control when performing arm-reaching movements. These findings may help clinical therapists in establishing objective indexes for poor grip-stability control screening and developing appropriate rehabilitation programs or health-promotion exercises that can improve grip strength and stability control in older people.

Summary and Assessment of Studies on Cardiac Aging in Nonhuman Primates

Nonhuman primates (NHP) are important translational models for cardiac aging. To assess progress in this research area and to provide a reference for other investigators, we identified papers indexed in PubMed to determine what species, ages, outcomes, treatments, and approaches have been studied. Since 1983, 33 studies of cardiac aging in NHP have been published. Of these, 27 used species of macaque, 6 baboon, 1 vervet, 1 orangutan, and 1 marmoset (some studies were multispecies). Common research approaches were echocardiography, ECG, and histology of the left ventricle. Only 10 studies performed sex-based analyses. The average age of the oldest macaque studied was 26 y. The reported mean lifespan of macaques in captivity is around 30 y. The age of the oldest baboon studied was 24 y. Baboons in captivity are reported to live on average to 21 y. Twelve studies took a "life course" approach, studying animals of a wide range of ages from less than or equal to 10 y through the late teens to thirties, and employing analyses designed to show change over time. Keeping NHP into old age is a major challenge for biomedical research. The ideal design is to start monitoring in early life and to track how cardiac structure and function change with age. Important issues for future research are an increased focus on life-course approaches, investment in existing life-course NHP cohorts, better reporting of study sample characteristics, more molecular studies to identify genetic risk factors and mechanisms, attention to sex as a biological variable, a move away from descriptive reports to mechanistic studies, development of biomarkers to predict disease risk, and exploration of interventions that are implemented early in life to prevent or delay age-related disease later in life. Reducing exposure to early life adversity, identifying early-life biomarkers of aging and age-related disease, and early treatment can contribute to longer health span.

Reliability of measurement using Image J for reach distance and movement angles in the functional reach test

[Purpose] The purpose of this study was to examine the test-retest reliability and minimal detectable change (MDC) of reach distance and movement angle analyses using Image J. [Participants and Methods] Thirty-eight healthy young males performed the functional reach test (FRT) twice, and their reach movements were recorded using a digital video camera. Image J was used to combine the digital photographs taken at the start position and maximum reach and to measure each movement. The measurements recorded were the movement distance of the third metacarpal bone (reach distance), anterior-superior iliac spine, and trochanter major, and the angles recorded were the acromion-malleolus lateralis, acromion-trochanter major, and trochanter major-malleolus lateralis. The reliability of all the measurements was analyzed using intraclass correlation coefficients (ICCs), Bland-Altman plots, and MDCs. [Results] The ICCs (1, 1) were >0.80 for all the outcomes. The Bland-Altman analysis revealed no systematic bias in any outcome. The MDC of reach distance was 18.3 mm. [Conclusion] Measurement using Image J for reach distance and movement angles in the FRT showed acceptable high test-retest reliability. Measurement of the FRT and the MDC calculated in this study could be used as a reference for further research.

Correlation between immunity from BCG and the morbidity and mortality of COVID-19

BACKGROUND

To investigate the association between parameters indicating immunity from BCG at country level (presence of BCG vaccination policy, BCG coverage, age-specific incidence of tuberculosis (TB)) and the morbidity and mortality of COVID-19.

METHODS

Country-specific data for COVID-19 cases and deaths, demographic details, BCG coverage and policy, age-specific TB incidence and income level were obtained. The crude COVID-19 cases and deaths per 100,000 population were calculated and assessed against the parameters indicating immunity from BCG using linear regression analysis.

RESULTS

Univariate analysis identified higher income level of a country to be significantly associated with COVID-19 cases (p < 0.0001) and deaths (p < 0.0001) but not with its case fatality rate. The association between COVID-19 and TB was strongest for TB incidence in patients > 65-years (Cases (rs = - 0.785,p = 0.0001)) and deaths (rs = - 0.647,p = 0.0001).Multivariate analysis identified the higher income level of a country and not having a universal BCG vaccination policy to affect the COVID-19 cases. The deaths were inversely affected by the presence of BCG vaccination policy and coverage; and positively by the TB incidence in patients > 65-years.

CONCLUSION

Significant inverse correlations observed between cases and deaths of COVID-19 and BCG related parameters highlights immunity from BCG as a likely explanation for the variation in COVID-19 across countries.

Shoulder Strength Requirements for Upper Limb Functional Tasks: Do Age and Rotator Cuff Tear Status Matter?

Understanding upper limb strength requirements for daily tasks is imperative for early detection of strength loss that may progress to disability due to age or rotator cuff tear. We quantified shoulder strength requirements for 5 upper limb tasks performed by 3 groups: uninjured young adults and older adults, and older adults with a degenerative supraspinatus tear prior to repair. Musculoskeletal models were developed for each group representing age, sex, and tear-related strength losses. Percentage of available strength used was quantified for the subset of tasks requiring the largest amount of shoulder strength. Significant differences in strength requirements existed across tasks: upward reach 105° required the largest average strength; axilla wash required the largest peak strength. However, there were limited differences across participant groups. Older adults with and without a tear used a larger percentage of their shoulder elevation (p < .001, p < .001) and external rotation (p < .001, p = .017) strength than the young adults, respectively. Presence of a tear significantly increased percentage of internal rotation strength compared to young (p < .001) and uninjured older adults (p = .008). Marked differences in strength demand across tasks indicate the need for evaluating a diversity of functional tasks to effectively detect early strength loss, which may lead to disability.

Prospective Associations of Low Muscle Mass and Function with 10-Year Falls Risk, Incident Fracture and Mortality in Community-Dwelling Older Adults

OBJECTIVES

Purpose: To compare the performance of low muscle mass and function with falls risk, incident fracture and mortality over 10 years.

METHODS

1041 participants (50% women; mean age 63±7.5 years) were prospectively followed for 10 years. Falls risk was measured using the Physiological Profile Assessment, fractures were self-reported and mortality was ascertained from the death registry. Appendicular lean mass (ALM) was assessed using dual energy X-ray absorptiometry. Four anthropometric: (ALM/height2, ALM/body mass index, ALM/weight×100, a residuals method of ALM on height and total body fat) and four performance-based measures: (handgrip strength, lower-limb muscle strength, upper and lower-limb muscle quality) were examined. Participants in the lowest 20% of the sex-specific distribution for each anthropometric and performance-based measure were classified has having low muscle mass or function. Regression analyses were used to estimate associations between each anthropometric and performance-based measure at baseline and 10-year falls risk, incident fractures and mortality.

RESULTS

Mean falls risk z-score at 10 years was 0.64 (SD 1.12), incident fractures and mortality over 10 years were 16% and 14% respectively. All baseline performance-based measures were significantly associated with higher falls risk score at 10 years. Low handgrip (RR 1.55, 95% CI: 1.09, 2.20) and ALM/body mass index (RR 1.54, 95% CI: 1.14, 2.08) were the only significant predictors of fracture and mortality respectively.

CONCLUSIONS

Low handgrip strength, a simple and inexpensive test could be considered in clinical settings for identifying future falls and fractures. ALM/ body mass index could be most suitable in estimating 10-year mortality risk, but requires specialised equipment.

Intellectual ability in young adulthood as an antecedent of physical functioning in older age

OBJECTIVES

low cognitive ability is associated with subsequent functional disability. Whether this association extends across adult life has been little studied. The aim of this study was to examine the association between intellectual ability in young adulthood and physical functioning during a 10-year follow-up in older age.

METHODS

three hundred and sixty persons of the Helsinki Birth Cohort Study (HBCS) male members, born between 1934 and 1944 and residing in Finland in 1971, took part in The Finnish Defence Forces Basic Intellectual Ability Test during the first 2 weeks of their military service training between 1952 and 1972. Their physical functioning was assessed twice using the Short Form 36 (SF-36) questionnaire at average ages of 61 and 71 years. A longitudinal path model linking Intellectual Ability Test score to the physical functioning assessments was used to explore the effect of intellectual ability in young adulthood on physical functioning in older age.

RESULTS

after adjustments for age at measurement, childhood socioeconomic status and adult BMI (kg/m(2)), better intellectual ability total and arithmetic and verbal reasoning subtest scores in young adulthood predicted better physical functioning at age 61 years (P values <0.021). Intellectual ability total and arithmetic and verbal reasoning subtest scores in young adulthood had indirect effects on physical functioning at age 71 years (P values <0.022) through better physical functioning at age 61 years. Adjustment for main chronic diseases did not change the results materially.

CONCLUSION

better early-life intellectual ability helps in maintaining better physical functioning in older age.

Predictive and Reactive Locomotor Adaptability in Healthy Elderly: A Systematic Review and Meta-Analysis

Background

Locomotor adaptability is based on the implementation of error-feedback information from previous perturbations to predictively adapt to expected perturbations (feedforward) and to facilitate reactive responses in recurring unexpected perturbations (‘savings’). The effect of aging on predictive and reactive adaptability is yet unclear. However, such understanding is fundamental for the design and application of effective interventions targeting fall prevention.

Methods

We systematically searched the Web of Science, MEDLINE, Embase and Science Direct databases as well as the reference lists of the eligible articles. A study was included if it addressed an investigation of the locomotor adaptability in response to repeated mechanical movement perturbations of healthy older adults (≥60 years). The weighted average effect size (WAES) of the general adaptability (adaptive motor responses to repeated perturbations) as well as predictive (after-effects) and reactive adaptation (feedback responses to a recurring unexpected perturbation) was calculated and tested for an overall effect. A subgroup analysis was performed regarding the factor age group [i.e., young (≤35 years) vs. older adults]. Furthermore, the methodological study quality was assessed.

Results

The review process yielded 18 studies [1009 participants, 613 older adults (70 ± 4 years)], which used various kinds of locomotor tasks and perturbations. The WAES for the general locomotor adaptability was 1.21 [95 % confidence interval (CI) 0.68–1.74, n = 11] for the older and 1.39 (95 % CI 0.90–1.89, n = 10) for the young adults with a significant (p < 0.05) overall effect for both age groups and no significant subgroup differences. Similar results were found for the predictive (older: WAES 1.10, 95 % CI 0.37–1.83, n = 8; young: WAES 1.54, 95 % CI 0.11–2.97, n = 7) and reactive (older: WAES 1.09, 95 % CI 0.22–1.96, n = 5; young: WAES 1.35, 95 % CI 0.60–2.09, n = 5) adaptation featuring significant (p < 0.05) overall effects without subgroup differences. The average score of the methodological quality was 67 ± 8 %.

Conclusions

The present meta-analysis provides elaborate statistical evidence that locomotor adaptability in general and predictive and reactive adaptation in particular remain highly effective in the elderly, showing only minor, not statistically significant age-related deficits. Consequently, interventions which use adaptation and learning paradigms including the application of the mechanisms responsible for an effective predictive and reactive dynamic stability control may progressively improve older adults’ recovery performance and, thus, reduce their risk of falling.

Electronic supplementary material

The online version of this article (doi:10.1007/s40279-015-0413-9) contains supplementary material, which is available to authorized users.

Analysis of effects of loading and postural demands on upper limb reaching in older adults using statistical parametric mapping

Continuous time-series data are frequently distilled into single values and analyzed using discrete statistical methods, underutilizing large datasets. Statistical parametric mapping (SPM) allows hypotheses over the entire spectrum, but consistency with discrete analyses of kinematic data is unclear. We applied SPM to evaluate effect of load and postural demands during reaching on thoracohumeral kinematics in older and young adults, and examined consistency between one-dimensional SPM and discrete analyses of the same dataset. We hypothesized that older adults would choose postures that bring the humerus anterior to the frontal plane (towards flexion) even for low demand tasks, and that SPM would reveal differences persisting over larger temporal portions of the reach. Ten healthy older (72.4±3.1yrs) and 16 young (22.9±2.5yrs) adults reached upward and forward with high and low loads. SPM and discrete t-tests were used to analyze group effects for elevation plane, elevation, and axial rotation joint angles and velocity. Older adults used more positive (anterior) elevation plane and less elevated postures to initiate and terminate reaching (p<0.008), with long duration differences during termination. When reaching upward, differences in elevation persisted over longer temporal periods at midreach for high loads (32-58% of reach) compared to low load (41-45%). SPM and discrete analyses were consistent, but SPM permitted clear identification of temporal periods over which differences persisted, while discrete methods allowed analysis of extracted values, like ROM. This work highlights the utility of SPM to analyze kinematics time series data, and emphasizes importance of task selection when assessing age-related changes in movement.

No association between blood telomere length and longitudinally assessed diet or adiposity in a young adult Filipino population

PURPOSE

Telomeres, DNA-protein structures that cap and protect chromosomes, are thought to shorten more rapidly when exposed to chronic inflammation and oxidative stress. Diet and nutritional status may be a source of inflammation and oxidative stress. However, relationships between telomere length (TL) and diet or adiposity have primarily been studied cross-sectionally among older, overweight/obese populations and yielded inconsistent results. Little is known about the relationship between diet or body composition and TL among younger, low- to normal-weight populations. It also remains unclear how cumulative exposure to a specific diet or body composition during the years of growth and development, when telomere attrition is most rapid, may be related to TL in adulthood.

METHODS

In a sample of 1459 young adult Filipinos, we assessed the relationship between blood TL at ages 20.8-22.5 and measures of BMI z-score, waist circumference, and diet collected between the ages of 8.5 and 22.5. TL was measured using monochrome multiplex quantitative PCR, and diet was measured using multiple 24-h recalls.

RESULTS

We found no associations between blood TL and any of the measures of adiposity or between blood TL and the seven dietary factors examined: processed meats, fried/grilled meats and fish, non-fried fish, coconut oil, fruits and vegetables, bread and bread products, and sugar-sweetened beverages.

CONCLUSIONS

Considering the inconsistencies in the literature and our null results, small differences in body composition and consumption of any single pro- or anti-inflammatory dietary component may not by themselves have a meaningful impact on telomere integrity, or the impact may differ across distinct ecological circumstances.

A Distinct Mitochondrial Genome with DUI-Like Inheritance in the Ocean Quahog Arctica islandica

Mitochondrial DNA (mtDNA) is strictly maternally inherited in metazoans. The major exception to this rule has been found in many bivalve species which allow the presence of different sex-linked mtDNA molecules. This mechanism, named doubly uniparental inheritance (DUI), is characterized by the presence of two mtDNAs: The female mtDNA is found in somatic tissue and female gonads, whereas the male mtDNA is usually found in male gonads and sperm. In this study we highlight the existence of two divergent mitochondrial haplotypes with a low genetic difference around 6–8% in Arctica islandica, a long-lived clam belonging to the Arcticidae, a sister group to the Veneridae in which DUI has been found. Phylogenetic analysis on cytochrome b and 16S sequences from somatic and gonadic tissues of clams belonging to different populations reveals the presence of the “divergent” type in male gonads only and the “normal” type in somatic tissues and female gonads. This peculiar segregation of divergent mtDNA types speaks for the occurrence of the DUI mechanism in A. islandica. This example also highlights the difficulties to assess the presence of such particular mitochondrial inheritance system and underlines the possible misinterpretations in phylogeographic and phylogenetic studies of bivalve species linked to the presence of two poorly differentiated mitochondrial genomes.

Functional measures, inflammatory markers and endothelin-1 as predictors of 360-day survival in centenarians

Centenarians represent a rapidly growing population. To better characterize this specific age group, we have performed a cross-sectional study to observe associations between functional measures and a range of biochemical markers, including inflammatory markers and their significance as predictors of 360-day survival. Medical history and physical and functional assessment (Mini-Mental State Examination (MMSE), Katz Index (activities of daily living, ADL) and Barthel Index (Barthel Index) of Activities of Daily Living, and Lawton Instrumental Activities of Daily Living Scale (Lawton IADL)) were conducted on 86 101.9 ± 1.2-year-old (mean ± SD) subjects (70 women, 16 men). Blood tests were performed on 84 subjects of whom 43 also had extended biomarker assessment. As a reference group 30 51.8 ± 5.0-year old healthy subjects (20 women, 10 men) were recruited. The centenarians received follow-up phone calls. Fifty-two centenarians (60 %) survived ≥360 days. Longer survival was associated with higher MMSE (hazard ratio, HR = 0.934, 95 % confidence interval (CI) 0.896-0.975, P = .002), ADL (HR = 0.840, 95 % CI 0.716-0.985, P = .032), Barthel Index (HR = 0.988, 95 % CI 0.977-0.999, P = .026), and albumin level (HR .926, 95 % CI 0.870-0.986, P .016) and with lower white blood cell (WBC) (HR = 1.161, 95 % CI 1.059-1.273, P = .001), C-reactive protein (CRP) (HR = 1.032, 95 % CI 1.014-1.050, P < .001), IL-6 (HR = 1.182, 95 % CI 1.047-1.335, P = .007), and endothelin-1 (ET-1) level (HR = 3.711, 95 % CI 1.233-11.169, P = .020). Centenarians had higher 360-day survival probability with MMSE ≥13 (P < .001), ADL ≥1 (P < .001), Barthel Index ≥15 (P < .001), Lawton IADL ≥10 points (P = .009), WBC <8.3 G/L (P = .039), CRP <10 mg/L (P < .001), IL-6 <6 pg/mL (P .002), and ET-1 <1.1 pg/mL (P .007). Our results indicate that functional measures, inflammatory markers, and endothelin-1 are predictors of 360-day survival in centenarians.