Reaction Time and Mortality from the Major Causes of Death:The NHANES-III Study

Studies examining the relation of information processing speed, as measured by reaction time, with mortality are scarce. We explored these associations in a representative sample of the US population

Falls in young, middle-aged and older community dwelling adults: perceived cause, environmental factors and injury

BACKGROUND: Falls in older people have been characterized extensively in the literature, however little has been reported regarding falls in middle-aged and younger adults. The objective of this paper is to describe the perceived cause, environmental influences and resultant injuries of falls in 1497 young (20–45 years), middle-aged (46–65 years) and older (> 65 years) men and women from the Baltimore Longitudinal Study on Aging. METHODS: A descriptive study where participants completed a fall history questionnaire describing the circumstances surrounding falls in the previous two years. RESULTS: The reporting of falls increased with age from 18% in young, to 21% in middle-aged and 35% in older adults, with higher rates in women than men. Ambulation was cited as the cause of the fall most frequently in all gender and age groups. Our population reported a higher percentage of injuries (70.5%) than previous studies. The young group reported injuries most frequently to wrist/hand, knees and ankles; the middle-aged to their knees and the older group to their head and knees. Women reported a higher percentage of injuries in all age groups. CONCLUSION: This is the first study to compare falls in young, middle and older aged men and women. Significant differences were found between the three age groups with respect to number of falls, activities engaged in prior to falling, perceived causes of the fall and where they fell

Social patterning in grip strength and in its association with age; A cross sectional analysis using the UK Household Longitudinal Study (UKHLS)

Background: Grip strength in early adulthood and midlife is an important predictor of disability, morbidity and mortality in later life. Understanding social patterning in grip strength at different life stages could improve insight into inequalities in age-related decline and when in the life course interventions could prevent the emergence of inequalities. Methods: Using United Kingdom Household Longitudinal Study (UKHLS) data on 19,292 people aged 16 to 99, fractional polynomial models were fitted to identify which function of age best described its association with grip strength. Linear regressions were used to establish whether socio-economic position (SEP), as measured by maternal education, highest educational qualification and income, was associated with grip strength. To test whether the association between age and grip strength was modified by SEP, interactions between SEP and the age terms were added. Differentiation was used to identify the age at which grip strength was highest for men and women and predicted levels of grip strength at peak were compared. Results: SEP is significantly associated with grip strength on all SEP measures, except education for men. Grip strength is highest at a younger age, and less strong for all measures of disadvantage for women and most measures for men. Interaction terms were not statistically significant indicating that the association between age and grip strength was not modified by SEP. Grip strength peak was 29.3 kg at age 33 for women with disadvantaged childhood SEP compared with 30.2 kg at age 35 for women with advantaged childhood SEP. Conclusion: The SEP differences in age and level of peak grip strength could be indicative of decline in muscle strength beginning earlier and from a lower base for disadvantaged groups. This could impact on the capacity for healthy ageing for those with disadvantaged SEP

Handgrip performance in relation to self-perceived fatigue, physical functioning and circulating IL-6 in elderly persons without inflammation

BACKGROUND: Low grip strength is recognized as one of the characteristics of frailty, as are systemic inflammation and the sensation of fatigue. Contrary to maximal grip strength, the physical resistance of the muscles to fatigue is not often included in the clinical evaluation of elderly patients. The aim of this study was to investigate if the grip strength and the resistance of the handgrip muscles to fatigue are related to self-perceived fatigue, physical functioning and circulating IL-6 in independently living elderly persons. METHODS: Forty elderly subjects (15 female and 25 male, mean age 75 ± 5 years) were assessed for maximal grip strength, as well as for fatigue resistance and grip work (respectively time and work delivered until grip strength drops to 50% of its maximum during sustained contraction), self perceived fatigue (VAS-Fatigue, Mob-Tiredness scale and the energy & fatigue items of the WHOQOL-100), self rated physical functioning (domain of physical functioning on the MOS short-form) and circulating IL-6. Relationships between handgrip performance and the other outcome measures were assessed. RESULTS: In the male participants, fatigue resistance was negatively related to actual sensation of fatigue (VAS-F, p < .05) and positively to circulating IL-6 (p < .05). When corrected for body weight, the relations of fatigue resistance with self-perceived fatigue became stronger and also apparent in the female. Grip strength and grip work were significantly related with several items of self-perceived fatigue and with physical functioning. These relations became more visible by means of higher correlation coefficients when grip strength and grip work were corrected for body weight. CONCLUSION: Well functioning elderly subjects presenting less handmuscle fatigue resistance and weaker grip strength are more fatigued, experience more tiredness during daily activities and are more bothered by fatigue sensations. Body weight seems to play an important role in the relation of muscle performance to fatigue perception. Elderly patients complaining from fatigue should be physically assessed, both evaluating maximal grip strength and fatigue resistance, allowing the calculation of grip work, which integrates both parameters. Grip work might best reflect the functional capacity resulting from the development of a certain strength level in relation to the time it can be maintained

Repeatability and validity of a standardised maximal step-up test for leg function-a diagnostic accuracy study

<p>Abstract</p> <p>Background</p> <p>Objectively assessed physical performance is a strong predictor for morbidity and premature death and there is an increasing interest in the role of sarcopenia in many chronic diseases. There is a need for robust and valid functional tests in clinical practice. Therefore, the repeatability and validity of a newly developed maximal step up test (MST) was assessed.</p> <p>Methods</p> <p>The MST, assessing maximal step-up height (MSH) in 3-cm increments, was evaluated in 60 healthy middle-aged subjects, 30 women and 30 men. The repeatability of MSH and the correlation between MSH and isokinetic knee extension peak torque (IKEPT), self-reported physical function (SF-36, PF), patient demographics and self-reported physical activity were investigated.</p> <p>Results</p> <p>The repeatability between occasions and between testers was 6 cm. MSH (range 12-45 cm) was significantly correlated to IKEPT, (<it>r </it>= 0.68, <it>P </it>< 0.001), SF-36 PF score, (<it>r </it>= 0.29, <it>P </it>= 0.03), sex, age, weight and BMI. The results also show that MSH above 32 cm discriminates subjects in our study with no limitation in self-reported physical function.</p> <p>Conclusions</p> <p>The standardised MST is considered a reliable leg function test for clinical practice. The MSH was related to knee extension strength and self-reported physical function. The precision of the MST for identification of limitations in physical function needs further investigation.</p

Quantitative Image Analysis Reveals Distinct Structural Transitions during Aging in Caenorhabditis elegans Tissues

Aging is associated with functional and structural declines in many body systems, even in the absence of underlying disease. In particular, skeletal muscles experience severe declines during aging, a phenomenon termed sarcopenia. Despite the high incidence and severity of sarcopenia, little is known about contributing factors and development. Many studies focus on functional aspects of aging-related tissue decline, while structural details remain understudied. Traditional approaches for quantifying structural changes have assessed individual markers at discrete intervals. Such approaches are inadequate for the complex changes associated with aging. An alternative is to consider changes in overall morphology rather than in specific markers. We have used this approach to quantitatively track tissue architecture during adulthood and aging in the C. elegans pharynx, the neuromuscular feeding organ. Using pattern recognition to analyze aged-grouped pharynx images, we identified discrete step-wise transitions between distinct morphologies. The morphology state transitions were maintained in mutants with pharynx neurotransmission defects, although the pace of the transitions was altered. Longitudinal measurements of pharynx function identified a predictive relationship between mid-life pharynx morphology and function at later ages. These studies demonstrate for the first time that adult tissues undergo distinct structural transitions reflecting postdevelopmental events. The processes that underlie these architectural changes may contribute to increased disease risk during aging, and may be targets for factors that alter the aging rate. This work further demonstrates that pattern analysis of an image series offers a novel and generally accessible approach for quantifying morphological changes and identifying structural biomarkers

Sequential Use of Transcriptional Profiling, Expression Quantitative Trait Mapping, and Gene Association Implicates MMP20 in Human Kidney Aging

Kidneys age at different rates, such that some people show little or no effects of aging whereas others show rapid functional decline. We sequentially used transcriptional profiling and expression quantitative trait loci (eQTL) mapping to narrow down which genes to test for association with kidney aging. We first performed whole-genome transcriptional profiling to find 630 genes that change expression with age in the kidney. Using two methods to detect eQTLs, we found 101 of these age-regulated genes contain expression-associated SNPs. We tested the eQTLs for association with kidney aging, measured by glomerular filtration rate (GFR) using combined data from the Baltimore Longitudinal Study of Aging (BLSA) and the InCHIANTI study. We found a SNP association (rs1711437 in MMP20) with kidney aging (uncorrected p = 3.6×10−5, empirical p = 0.01) that explains 1%–2% of the variance in GFR among individuals. The results of this sequential analysis may provide the first evidence for a gene association with kidney aging in humans

Effect of standing posture during whole body vibration training on muscle morphology and function in older adults: A randomised controlled trial

<p>Abstract</p> <p>Background</p> <p>Whole body vibration (WBV) is a novel modality of exercise shown to improve musculoskeletal function. This study aims to examine the effects of standing posture during low magnitude WBV training on muscle function and muscle morphology in older adults.</p> <p>Methods</p> <p>Nineteen men and women (50-80 years) were recruited to a three month randomised controlled trial and allocated to one of three groups: WBV with flexed knees (FK), WBV with locked knees (LK), or sham WBV with flexed knees (CON). Exposure was intermittent (1 min WBV:1 min rest) for 20 min, three times per week for 13 weeks. Measurements were taken at baseline and at three months. Primary outcomes included upper and lower body muscle function (strength, power and velocity). Secondary outcomes were muscle morphology, balance, habitual and maximal gait velocity, stair climb power, and chair stand performance.</p> <p>Results</p> <p>Sixteen subjects completed the study. Relative (%) upper body contraction velocity improved significantly after WBV with FK compared to LK (FK 16.0%, LK -7.6%, CON 4.7, p = 0.01). Relative upper body strength (LK 15.1%, p = 0.02; FK 12.1%, p = 0.04; CON 4.7%) increased significantly following WBV compared to control. Absolute (p = 0.05) and relative (p = 0.03) lower leg strength significantly improved with both standing postures (LK 14.4%; FK 10.7%; CON 1.3%). Only the LK group differed significantly from CON in relative leg strength gains (p = 0.02). Potentially clinically meaningful but statistically non-significant improvements in lower leg muscle cross-sectional area (LK 3.7 cm², FK 2.4 cm², CON 2.2 cm²p = 0.13) were observed after WBV with LK compared to the other groups. No significant effects of WBV on any functional performance tests were observed.</p> <p>Conclusions</p> <p>Our results suggest that WBV may improve muscle strength and contraction velocity in some muscle groups in older adults. However, hypothesised differential adaptation to standing posture (FK > LK) was observed only for upper body contraction velocity, making recommendations regarding this prescriptive element inconclusive. The efficacy, mechanism of action and long term feasibility of WBV for musculoskeletal health in older adults warrants continued investigation in robustly designed, sufficiently powered future studies.</p> <p>Trial Registration</p> <p>ACTRN12609000353291.</p

Lean mass, muscle strength, and physical function in a diverse population of men: a population-based cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Age-related declines in lean body mass appear to be more rapid in men than in women but our understanding of muscle mass and function among different subgroups of men and their changes with age is quite limited. The objective of this analysis is to examine racial/ethnic differences and racial/ethnic group-specific cross-sectional age differences in measures of muscle mass, muscle strength, and physical function among men.</p> <p>Methods</p> <p>Data were obtained from the Boston Area Community Health/Bone (BACH/Bone) Survey, a population-based, cross-sectional, observational survey. Subjects included 1,157 black, Hispanic, and white randomly-selected Boston men ages 30-79 y. Lean mass was assessed by dual-energy x-ray absorptiometry. Upper extremity (grip) strength was assessed with a hand dynamometer and lower extremity physical function was derived from walk and chair stand tests. Upper extremity strength and lower extremity physical function were also indexed by lean mass and lean mass was indexed by the square of height.</p> <p>Results</p> <p>Mean age of the sample was 47.5 y. Substantial cross-sectional age differences in grip strength and physical function were consistent across race/ethnicity. Racial/ethnic differences, with and without adjustment for covariates, were evident in all outcomes except grip strength. Racial differences in lean mass did not translate into parallel differences in physical function. For instance, multivariate modeling (with adjustments for age, height, fat mass, self-rated health and physical activity) indicated that whereas total body lean mass was 2.43 kg (approximately 5%) higher in black compared with white men, black men had a physical function score that was approximately 20% lower than white men.</p> <p>Conclusions</p> <p>In spite of lower levels of lean mass, the higher levels of physical function observed among white compared with non-white men in this study appear to be broadly consistent with known racial/ethnic differences in outcomes.</p