30 research outputs found
A multi-cohort study of polymorphisms in the GH/IGF axis and physical capability: the HALCyon programme
No full textBackground: Low muscle mass and function have been associated with poorer indicators of physical capability in olderpeople, which are in-turn associated with increased mortality rates. The growth hormone/insulin-like growth factor (GH/IGF)axis is involved in muscle function and genetic variants in genes in the axis may influence measures of physical capability.Methods: As part of the Healthy Ageing across the Life Course (HALCyon) programme, men and women from seven UKcohorts aged between 52 and 90 years old were genotyped for six polymorphisms: rs35767 (IGF1), rs7127900 (IGF2),rs2854744 (IGFBP3), rs2943641 (IRS1), rs2665802 (GH1) and the exon-3 deletion of GHR. The polymorphisms have previouslybeen robustly associated with age-related traits or are potentially functional. Meta-analysis was used to pool within-studygenotypic effects of the associations between the polymorphisms and four measures of physical capability: grip strength,timed walk or get up and go, chair rises and standing balance.Results: Few important associations were observed among the several tests. We found evidence that rs2665802 in GH1 wasassociated with inability to balance for 5 s (pooled odds ratio per minor allele = 0.90, 95% CI: 0.82–0.98, p-value = 0.01,n = 10,748), after adjusting for age and sex. We found no evidence for other associations between the polymorphisms andphysical capability traits.Conclusion: Our findings do not provide evidence for a substantial influence of these common polymorphisms in the GH/IGF axis on objectively measured physical capability levels in older adults
Body mass index, muscle strength and physical performance in older adults from eight cohort studies: the HALCyon programme.
No full textObjective
To investigate the associations of body mass index (BMI) and grip strength with objective measures of physical performance (chair rise time, walking speed and balance) including an assessment of sex differences and non-linearity.
Methods
Cross-sectional data from eight UK cohort studies (total N = 16 444) participating in the Healthy Ageing across the Life Course (HALCyon) research programme, ranging in age from 50 to 90+ years at the time of physical capability assessment, were used. Regression models were fitted within each study and meta-analysis methods used to pool regression coefficients across studies and to assess the extent of heterogeneity between studies.
Results
Higher BMI was associated with poorer performance on chair rise (N = 10 773), walking speed (N = 9 761) and standing balance (N = 13 921) tests. Higher BMI was associated with stronger grip strength in men only. Stronger grip strength was associated with better performance on all tests with a tendency for the associations to be stronger in women than men; for example, walking speed was higher by 0.43 cm/s (0.14, 0.71) more per kg in women than men. Both BMI and grip strength remained independently related with performance after mutual adjustment, but there was no evidence of effect modification. Both BMI and grip strength exhibited non-linear relations with performance; those in the lowest fifth of grip strength and highest fifth of BMI having particularly poor performance. Findings were similar when waist circumference was examined in place of BMI.
Conclusion
Older men and women with weak muscle strength and high BMI have considerably poorer performance than others and associations were observed even in the youngest cohort (age 53). Although causality cannot be inferred from observational cross-sectional studies, our findings suggest the likely benefit of early assessment and interventions to reduce fat mass and improve muscle strength in the prevention of future functional limitations
HALCyon Healthy Ageing across the Life Course
No full text1) Meta-data (for existing data) generated by the HALCyon project
One of the main aims of HALCyon was to perform comparable analyses across 9 British cohort studies which tested the inter-relationships between: physical and cognitive capability; social and psychological wellbeing and; underlying biological markers of ageing. Another main aim was to test the associations of factors across life with each of these three sets of measures. In the majority of cases, this involved harmonising secondary data from the 9 participating studies which had been provided to the HALCyon study team by cohort PIs. The nine studies included were: the MRC National Survey of Health and Development (NSHD), the National Child Development Study (NCDS), Lothian Birth Cohort 1921 (LBC1921), Aberdeen Birth Cohort 1936 (ABC1936), Herfordshire Ageing Study (HAS), Hertfordshire Cohort Study (HCS), the Boyd Orr Cohort study, the English Longitudinal Study of Ageing (ELSA) and the Caerphilly Prospective Study (CaPS) .
The first step in this process was to document details of the potentially relevant variables already collected and available in each study. The second step in this process was to write syntax which cleaned and recoded relevant variables for use in comparable analyses.
In addition to the publications produced (see www.halcyon.ac.uk), other key outputs from HALCyon are: (i) the documentation created which lists out the comparable variables available in each cohort for topics of relevance to HALCyon; (ii) Stata syntax which was used to clean and recode existing data for use in analyses that were comparable across cohorts. These meta-data documents (i.e. variable lists by topic and stata do files) have been uploaded.
2) New data generated by the HALCyon project
The NDA grant for HALCyon also included funds to:
- collect comparable data on wellbeing in: Hertfordshire Cohort Study (HCS); Caerphilly Prospective Study (CaPS); Aberdeen Birth Cohort 1936 (ABC1936)
- measure telomere length using existing blood samples in: Lothian Birth Cohort 1921 (LBC1921); CaPS; Hertfordshire Ageing study (HAS); NSHD (sub-set of samples)
- perform cortisol assays using existing saliva samples in: CaPS and NSHD
- undertake 60 qualitative interviews (30 each) in: HCS; NSHD.
HALCyon makes use of secondary data from 9 different UK cohort studies so each study is responsible for governing their own consent forms. However, the consent form for the qualitative interviews has been uploaded. A user guide on the data/metadata that is available has also been uploaded.
HALCyon brings together an interdisciplinary group of scientists working on nine UK cohort studies to understand three aspects of healthy ageing: physical and cognitive capability (the ability to undertake the physical and mental tasks of everyday living), psychological and social wellbeing (how people feel and how they function in terms of relationships and social activities), and the biology of ageing, including cortisol (one of the body's stress hormones), telomere length (the cell's natural clock that tells the body how old it is) and genetic factors.
The eight projects will investigate how individual factors such as early development, lifetime health, personality and nutrition, and characteristics of areas in which study members have lived influence these indicators of healthy ageing. These factors may explain why some older people live fulfilled and active lives and why differences exist between men and women, or between social groups. Some cohort members will be interviewed to find out how they understand their life history and experiences and their response to ageing.
Interactions between the scientists and experts in policy, practice and user involvement will ensure that the new knowledge gained will improve the lives of older people.</p
Childhood socioeconomic position and objectively measured physical capability levels in adulthood: a systematic review and meta-analysis
No full text<p><b>Background:</b> Grip strength, walking speed, chair rising and standing balance time are objective measures of physical capability that characterise current health and predict survival in older populations. Socioeconomic position (SEP) in childhood may influence the peak level of physical capability achieved in early adulthood, thereby affecting levels in later adulthood. We have undertaken a systematic review with meta-analyses to test the hypothesis that adverse childhood SEP is associated with lower levels of objectively measured physical capability in adulthood.</p>
<p><b>Methods and Findings:</b> Relevant studies published by May 2010 were identified through literature searches using EMBASE and MEDLINE. Unpublished results were obtained from study investigators. Results were provided by all study investigators in a standard format and pooled using random-effects meta-analyses. 19 studies were included in the review. Total sample sizes in meta-analyses ranged from N = 17,215 for chair rise time to N = 1,061,855 for grip strength. Although heterogeneity was detected, there was consistent evidence in age adjusted models that lower childhood SEP was associated with modest reductions in physical capability levels in adulthood: comparing the lowest with the highest childhood SEP there was a reduction in grip strength of 0.13 standard deviations (95% CI: 0.06, 0.21), a reduction in mean walking speed of 0.07 m/s (0.05, 0.10), an increase in mean chair rise time of 6% (4%, 8%) and an odds ratio of an inability to balance for 5s of 1.26 (1.02, 1.55). Adjustment for the potential mediating factors, adult SEP and body size attenuated associations greatly. However, despite this attenuation, for walking speed and chair rise time, there was still evidence of moderate associations.</p>
<p><b>Conclusions:</b> Policies targeting socioeconomic inequalities in childhood may have additional benefits in promoting the maintenance of independence in later life.</p>
Profiles of physical, emotional and psychosocial wellbeing in the Lothian birth cohort 1936
No full textAbstract Background Physical, emotional, and psychosocial wellbeing are important domains of function. The aims of this study were to explore the existence of separable groups among 70-year olds with scores representing physical function, perceived quality of life, and emotional wellbeing, and to characterise any resulting groups using demographic, personality, cognition, health and lifestyle variables. Methods We used latent class analysis (LCA) to identify possible groups. Results Results suggested there were 5 groups. These included High (n = 515, 47.2% of the sample), Average (n = 417, 38.3%), and Poor Wellbeing (n = 37, 3.4%) groups. The two other groups had contrasting patterns of wellbeing: one group scored relatively well on physical function, but low on emotional wellbeing (Good Fitness/ Low Spirits,n = 60, 5.5%), whereas the other group showed low physical function but relatively well emotional wellbeing (Low Fitness/Good Spirits, n = 62, 5.7%). Salient characteristics that distinguished all the groups included smoking and drinking behaviours, personality, and illness. Conclusions Despite there being some evidence of these groups, the results also support a largely one-dimensional construct of wellbeing in old age—for the domains assessed here—though with some evidence that some individuals have uneven profiles.</p
How useful are the SF-36 sub-scales in older people? Mokken scaling of data from the HALCyon programme
No full textPurpose: To evaluate two psychometric properties of SF-36, namely unidimensionality and reliability.Methods: The data are from three cohorts in the HALCyon collaborative research programme into healthy ageing: Aberdeen Birth Cohort 1936 (n = 428), Hertfordshire Ageing Study (n = 358) and Hertfordshire Cohort Study (n = 3,216). The Mokken scaling model was applied to each sub-scale of SF-36 to evaluate unidimensionality as indicated by scalability. The lower bound for internal consistency reliability was determined by Cronbach’s alpha. Results: All six sub-scales of SF-36, with the exception of general health (GH) and mental health (MH), demonstrated strong scalability (0.5 ? H < 1). The results were consistent across all 3 cohorts. Both GH and MH showed medium scalability (0.4 ? H <0.55), although individual items ‘sick easier..’, ‘as healthy as..’ and ‘expect to get worse’ of the GH sub-scale and ‘nervous’, ‘happy’ in the MH sub-scale had low scalability (H < 0.4) in the oldest cohort (aged 73–83). Cronbach’s alphas for all sub-scales were between 0.70 and 0.92. Conclusions: The unidimensionality and reliability of the sub-scales of SF-36 are sufficient to make this a useful measure of health-related quality of life in older people. Caution is needed when interpreting the results for GH and MH in the oldest cohort due to the poor unidimensionality. <br/
The structure of the hospital anxiety and depression scale in four cohorts of community-based, healthy older people: the HALCyon program
No full textBackground: The Hospital Anxiety and Depression Scale (HADS) is widely used but evaluation of its psychometric properties has produced equivocal results. Little is known about its structure in non-clinical samples of older people.Methods: We used data from four cohorts in the HALCyon collaborative research program into healthy aging: the Caerphilly Prospective Study, the Hertfordshire Ageing Study, the Hertfordshire Cohort Study, and the Lothian Birth Cohort 1921. We used exploratory factor analysis and confirmatory factor analysis with multi-group comparisons to establish the structure of the HADS and test for factorial invariance between samples.Results: Exploratory factor analysis showed a bi-dimensional structure (anxiety and depression) of the scale in men and women in each cohort. We tested a hypothesized three-factor model but high correlations between two of the factors made a two-factor model more psychologically plausible. Multi-group confirmatory factor analysis revealed that the sizes of the respective item loadings on the two factors were effectively identical in men and women from the same cohort. There was more variation between cohorts, particularly those from different parts of the U.K. and in whom the HADS was administered differently. Differences in social-class distribution accounted for part of this variation.Conclusions: Scoring the HADS as two subscales of anxiety and depression is appropriate in non-clinical populations of older men and women. However, there were differences between cohorts in the way that individual items were linked with the constructs of anxiety and depression, perhaps due to differences in sociocultural factors and/or in the administration of the scale.<br/
Associations between a Polymorphism in the Pleiotropic GCKR and Age-Related Phenotypes: The HALCyon Programme
No full textBackground
The glucokinase regulatory protein encoded by GCKR plays an important role in glucose metabolism and a single nucleotide polymorphism (SNP) rs1260326 (P446L) in the gene has been associated with several age-related biomarkers, including triglycerides, glucose, insulin and apolipoproteins. However, associations between SNPs in the gene and other ageing phenotypes such as cognitive and physical capability have not been reported.
Methods
As part of the Healthy Ageing across the Life Course (HALCyon) collaborative research programme, men and women from five UK cohorts aged between 44 and 90+ years were genotyped for rs1260326. Meta-analysis was used to pool within-study genotypic associations between the SNP and several age-related phenotypes, including body mass index (BMI), blood lipid levels, lung function, and cognitive and physical capability.
Results
We confirm the associations between the minor allele of the SNP and higher triglycerides and lower glucose levels. We also observed a triglyceride-independent association between the minor allele and lower BMI (pooled beta on z-score = −0.04, p-value = 0.0001, n = 16,251). Furthermore, there was some evidence for gene-environment interactions, including physical activity attenuating the effects on triglycerides. However, no associations were observed with measures of cognitive and physical capability.
Conclusion
Findings from middle-aged to older adults confirm associations between rs1260326 GCKR and triglycerides and glucose, suggest possible gene-environment interactions, but do not provide evidence that its relevance extends to cognitive and physical capability
Dysregulation of the hypothalamic pituitary adrenal (HPA) axis and physical performance at older ages: an individual participant meta-analysis
No full textThe association between functioning of the hypothalamic pituitary adrenal (HPA) axis and physical performance at older ages remains poorly understood. We carried out meta-analyses to test the hypothesis that dysregulation of the HPA axis, as indexed by patterns of diurnal cortisol release, is associated with worse physical performance. Data from six adult cohorts (ages 50–92 years) were included in a two stage meta-analysis of individual participant data. We analysed each study separately using linear and logistic regression models and then used meta-analytic methods to pool the results. Physical performance outcome measures were walking speed, balance time, chair rise time and grip strength. Exposure measures were morning (serum and salivary) and evening (salivary) cortisol. Total sample sizes in meta-analyses ranged from n = 2146 for associations between morning Cortisol Awakening Response and balance to n = 8448 for associations between morning cortisol and walking speed. A larger diurnal drop was associated with faster walking speed (standardised coefficient per SD increase 0.052, 95% confidence interval (CI) 0.029, 0.076, p < 0.001; age and gender adjusted) and a quicker chair rise time (standardised coefficient per SD increase ?0.075, 95% CI ?0.116, ?0.034, p < 0.001; age and gender adjusted). There was little evidence of associations with balance or grip strength. Greater diurnal decline of the HPA axis is associated with better physical performance in later life. This may reflect a causal effect of the HPA axis on performance or that other ageing-related factors are associated with both reduced HPA reactivity and performance
Associations between APOE and low-density lipoprotein cholesterol genotypes and cognitive and physical capability: the HALCyon programme
No full textThe APOE ε2/3/4 genotype has been associated with low-density lipoprotein cholesterol (LDL-C) and Alzheimer disease. However, evidence for associations with measures of cognitive performance in adults without dementia has been mixed, as it is for physical performance. Associations may also be evident in other genotypes implicated in LDL-C levels. As part of the Healthy Ageing across the Life Course (HALCyon) collaborative research programme, genotypic information was obtained for APOE ε2/3/4, rs515135 (APOB), rs2228671 (LDLR) and rs629301 (SORT1) from eight cohorts of adults aged between 44 and 90 + years. We investigated associations with four measures of cognitive (word recall, phonemic fluency, semantic fluency and search speed) and physical capability (grip strength, get up and go/walk speed, timed chair rises and ability to balance) using meta-analyses. Overall, little evidence for associations between any of the genotypes and measures of cognitive capability was observed (e.g. pooled beta for APOE ε4 effect on semantic fluency z score = -0.02; 95 % CI = -0.05 to 0.02; p value = 0.3; n = 18,796). However, there was borderline evidence within studies that negative effects of APOE ε4 on nonverbal ability measures become more apparent with age. Few genotypic associations were observed with physical capability measures. The findings from our large investigation of middle-aged to older adults in the general population suggest that effects of APOE on cognitive capability are at most modest and are domain- and age-specific, while APOE has little influence on physical capability. In addition, other LDL-C-related genotypes have little impact on these traits
