Morbidities among older workers and work exit: the HEAF cohort.

BACKGROUND: Governments need people to work to older ages, but the prevalence of chronic disease and comorbidity increases with age and impacts work ability. AIMS: To investigate the effects of objective health diagnoses on exit from paid work amongst older workers. METHODS: Health and Employment After Fifty (HEAF) is a population cohort of adults aged 50-64 years recruited from English GP practices which contribute to the Clinical Practice Research Datalink (CPRD). Participants have completed questionnaires about health and work at baseline and annually for 2 years: their responses were linked with their objective health diagnoses from the CPRD and data analysed using Cox regression. RESULTS: Of 4888 HEAF participants ever in paid work, 580 (25%) men and 642 (25%) women exited employment, 277 of them mainly or partly for a health reason (health-related job loss (HRJL)). Amongst HEAF participants who remained in work (n = 3666) or who exited work but not for health reasons (n = 945), there was a similar prevalence of background health conditions. In men and women, HRJL was associated with inflammatory arthritis, sleep disorders, common mental health conditions and musculoskeletal pain. There were however gender differences: widespread pain and lower limb osteoarthritis were associated with HRJL in women but hypertension and cardiovascular disease in men. CONCLUSIONS: Improved diagnosis and management of common conditions might be expected to increase working lives. Workplace well-being interventions targeting obesity and increasing mobility might contribute to extended working lives. Employers of predominantly female, as compared with male workforces may need different strategies to retain older workers.

Relationships between markers of inflammation and bone density: findings from the Hertfordshire Cohort Study.

Among 365 Hertfordshire Cohort Study participants (aged 59-71 years at baseline), higher adiponectin and adiponectin to leptin ratios were associated with lower baseline lumbar spine and femoral neck bone mineral density (BMD). Lower IL-10 was associated with accelerated decline in lumbar spine BMD. This suggests that bone health can be influenced by changes in immune phenotype and alterations in adipokine homeostasis. INTRODUCTION: The aim of this study was to examine the association between indices of inflammation and BMD in a population-based cohort of older adults in the UK. METHODS: Analyses were based on a sample of 194 men and 171 women of the Hertfordshire Cohort Study (community-living, older adults). Dual energy X-ray absorptiometry (DXA) was performed at the lumbar spine and proximal femur at baseline and repeated at a median of 4.5 years (inter-quartile range 3.6 to 5.2). Inflammatory markers (CRP, TNF, IL-1ß, IL-6, IL-8, IL-10, adiponectin and leptin) were ascertained at baseline using enzyme-linked immunosorbent assay (ELISA) techniques and Bio-Plex Pro Assays. Gender-adjusted linear regression was used to examine the associations between markers of inflammation and outcomes with and without adjustment for anthropometric and lifestyle factors. RESULTS: The mean (SD) ages at baseline were 64.4 (2.5) and 66.5 (2.7) years for men and women respectively. Higher levels of adiponectin and adiponectin to leptin ratios were each associated with lower baseline lumbar spine and femoral neck BMD in gender-adjusted (p < 0.01) and fully adjusted (p < 0.05) analyses. Lower levels of IL-10 and TNF were each associated with accelerated decline in lumbar spine BMD in both gender-adjusted (p ≤ 0.05) and fully adjusted (p < 0.05) analyses. CONCLUSIONS: In a cohort of older adults, high levels of adiponectin and adiponectin to leptin ratios were both associated with lower BMD at the lumbar spine and femoral neck at baseline, and lower IL-10 was associated with accelerated decline in BMD at the lumbar spine. This adds weight to the theory that bone health can be influenced by changes in immune phenotype and alterations in adipokine homeostasis.

Correlates of Level and Loss of Grip Strength in Later Life: Findings from the English Longitudinal Study of Ageing and the Hertfordshire Cohort Study.

Characterisation of grip strength (GS) using isometric dynamometry is central to the definition of sarcopenia. Determinants of low GS include: older age, shorter stature, low physical activity, poor nutrition, socioeconomic disadvantage and multimorbidity. Less is known about risk factors for accelerated loss of GS. We investigated determinants of level and 8-year loss of GS in 3703 men and women (aged 52-82 years) in the English Longitudinal Study of Ageing (ELSA). Four hundred and forty-one men and women (aged 59-71 years) who participated in a 10-year follow-up of the Hertfordshire Cohort Study (HCS) were used for replication. Variables were harmonised between cohorts. Change in GS was characterised using mixed-effects models in ELSA and a residual change approach in HCS and analysed for men and women combined. Men in ELSA and HCS had higher average levels of GS at baseline, and accelerated rates of loss, compared with women. In ELSA, older age, shorter stature and multimorbidity were correlated with lower level, and accelerated rate of loss, of GS in both sexes (accelerated loss of 0.04 (95% CI 0.00-0.08) standard deviation scores per additional morbidity after multivariable adjustment). Socioeconomic disadvantage, low level of physical activity and poorer self-reported health were also correlated with low GS level, but not loss rate, after multivariable adjustment. Analysis in HCS yielded similar results. Our results identify multimorbidity as a modifiable determinant of loss of muscle strength in later life, and raise the possibility that developmental influences may impact on rate of involutional decline in muscle strength.

Muscle Mass, Muscle Morphology and Bone Health Among Community-Dwelling Older Men: Findings from the Hertfordshire Sarcopenia Study (HSS).

Sarcopenia and osteoporosis are associated with poor health outcomes in older people. Relationships between muscle and bone have typically been reported at a functional or macroscopic level. The aims of this study were to describe the relationships between muscle morphology and bone health among participants of the Hertfordshire Sarcopenia Study (HSS). 105 older men, mean age 72.5 (SD 2.5) years, were recruited into the HSS. Whole body lean mass as well as appendicular lean mass, lumbar spine and femoral neck bone mineral content (BMC) and bone mineral density (BMD) were obtained through dual-energy X-ray absorptiometry scanning. Percutaneous biopsy of the vastus lateralis was performed successfully in 99 participants. Image analysis was used to determine the muscle morphology variables of slow-twitch (type I) and fast-twitch (type II) myofibre area, myofibre density, capillary and satellite cell (SC) density. There were strong relationships between whole and appendicular lean body mass in relation to femoral neck BMC and BMD (r ≥ 0.43, p < 0.001). Type II fibre area was associated with both femoral neck BMC (r = 0.27, p = 0.01) and BMD (r = 0.26, p = 0.01) with relationships robust to adjustment for age and height. In unadjusted analysis, SC density was associated with whole body area (r = 0.30, p = 0.011) and both BMC (r = 0.26, p = 0.031) and area (r = 0.29, p = 0.017) of the femoral neck. We have demonstrated associations between BMC and changes in muscle at a cellular level predominantly involving type II myofibres. Interventions targeted at improving muscle mass, function and quality may improve overall musculoskeletal health. Larger studies that include women are needed to explore these relationships further.

Relationships Between Markers of Inflammation and Muscle Mass, Strength and Function: Findings from the Hertfordshire Cohort Study.

We investigated the longitudinal relationships between inflammation markers and the following outcomes in a UK cohort study: appendicular lean mass (ALM); walking speed; level and change in grip strength; and sarcopenia defined by the European Working Group on Sarcopenia in Older People. Analyses were based on 336 community-dwelling older men and women (aged 59-70 years) who participated in the Hertfordshire Cohort Study (HCS). Inflammation markers were ascertained at baseline using enzyme-linked immunosorbent assay techniques and Bio-Plex Pro Assays. Grip strength was measured at baseline and follow-up [median follow-up time: 10.8 years (inter-quartile range 10.2-11.6)] and change in grip strength was ascertained using a residual change approach. At follow-up, ALM was ascertained using dual-energy X-ray absorptiometry, customary walking speed was measured and sarcopenia status was ascertained. Gender-adjusted linear and Poisson regression was used to examine the associations between inflammation markers and outcomes with and without adjustment for anthropometric and lifestyle factors. Higher C-reactive protein was associated (p < 0.04) with lower grip strength and accelerated decline in grip strength from baseline to follow-up. Higher cortisol was associated with lower ALM (p < 0.05). Higher interleukin-8 (IL-8) was associated with lower ALM (p < 0.05) and increased risk of sarcopenia [fully-adjusted relative risk per SD increase in IL-8: 1.37 (95% CI 1.10, 1.71), p = 0.005]. All associations were robust in fully-adjusted analyses. Inflammation markers were associated with measures of muscle mass, strength and function in HCS. Further work is required to replicate these associations and to delineate the underlying mechanisms.

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.

Skeletal muscle morphology in sarcopenia defined using the EWGSOP criteria: findings from the Hertfordshire Sarcopenia Study (HSS).

BACKGROUND: Sarcopenia is defined as the loss of muscle mass and function with age and is associated with decline in mobility, frailty, falls and mortality. There is considerable interest in understanding the underlying mechanisms. Our aim was to characterise muscle morphology changes associated with sarcopenia among community dwelling older men. METHODS: One hundred and five men aged 68-76 years were recruited to the Hertfordshire Sarcopenia Study (HSS) for detailed characterisation of muscle including measures of muscle mass, strength and function. Muscle tissue was obtained from a biopsy of the vastus lateralis for 99 men and was processed for immunohistochemical studies to determine myofibre distribution and area, capillarisation and satellite cell (SC) density. RESULTS: Six (6 %) men had sarcopenia as defined by the European Working Group on Sarcopenia in Older People (EWGSOP) criteria. These men had lower SC density (1.7 cells/mm(2) vs 3.8 cells/mm(2), p = 0.06) and lower SC/fibre ratio (0.02 vs 0.06, p = 0.06) than men without sarcopenia. Although men with sarcopenia tended to have smaller myofibres and lower capillary to fibre ratio, these relationships were not statistically significant. CONCLUSION: We have shown that there may be altered muscle morphology parameters in older men with sarcopenia. These results have the potential to help identify cell and molecular targets for therapeutic intervention. This work now requires extension to larger studies which also include women.

Exposure to heavy physical occupational activities during working life and bone mineral density at the hip at retirement age.

BACKGROUND: People in sedentary occupations are at increased risk of hip fracture. Hip fracture is significantly associated with low bone mineral density (BMD) measured at the hip. Physical activity is important in the development and maintenance of BMD, but the effects of occupational physical activity on bone health are unclear. We investigated the influence of lifetime physical activity on BMD at the hip. METHODS: This was a cross-sectional epidemiological study of the associations between total hip BMD measured by dual-energy X-ray absorptiometry at retirement age and lifetime exposure to occupational physical workload (standing/walking ≥4 h/day; lifting ≥25 kg; energetic work sufficient to induce sweating and manual work). RESULTS: Complete data on occupational exposures were available for 860 adults (488 men and 372 women) who had worked ≥20 years. Their mean age was 65 years, and many reported heavy physical workplace activities over prolonged durations. There were no statistically significant associations between total hip BMD and any of these measures of lifetime occupational physical activity in men or women. CONCLUSIONS: Lifetime cumulative occupational activity was not associated with hip BMD at retirement age. Our findings suggest that, if sedentary work conveys an increased risk of hip fracture, it is unlikely that the mechanism is through reductions in BMD at the hip and may relate to other physical effects, such as falls risk. Further studies will be needed to test this hypothesis.

Dietary total antioxidant capacity is related to glucose tolerance in older people: the Hertfordshire Cohort Study.

BACKGROUND AND AIMS: Dietary antioxidants may play a protective role in the aetiology of type 2 diabetes. However, observational studies that examine the relationship between the antioxidant capacity of the diet and glucose metabolism are limited, particularly in older people. We aimed to examine the relationships between dietary total antioxidant capacity (TAC) and markers of glucose metabolism among 1441 men and 1253 women aged 59-73 years who participated in the Hertfordshire Cohort Study, UK. METHODS AND RESULTS: Diet was assessed by food frequency questionnaire. Dietary TAC was estimated using published databases of TAC measured by four different assays: oxygen radical absorbance capacity (ORAC), ferric-reducing ability of plasma (FRAP), total radical-trapping antioxidant parameter (TRAP) and trolox equivalent antioxidant capacity (TEAC). Fasting and 120-min plasma glucose and insulin concentrations were measured during a standard 75-g oral glucose tolerance test. In men, dietary TAC estimated by all four assays was inversely associated with fasting insulin concentration and homoeostasis model assessment of insulin resistance (HOMA-IR); with the exception of ORAC, dietary TAC was also inversely related to 120-min glucose concentration. There were no associations with fasting glucose or 120-min insulin concentrations. In women, with the exception of the association between ORAC and 120-min insulin concentration, dietary TAC estimated by all assays showed consistent inverse associations with fasting and 120-min glucose and insulin concentrations and HOMA-IR. These associations were more marked among women with BMI ≥ 30 kg/m(2). CONCLUSION: These findings suggest dietary TAC may have important protective effects on glucose tolerance, especially in older obese women.

The relationship of dietary patterns with adult lung function and COPD.

Previous studies of diet and lung function have focused on associations with individual nutrients and foods, and not dietary patterns. The relationships between dietary patterns and lung function and spirometrically defined chronic obstructive pulmonary disease (COPD) were investigated in 1,551 males and 1,391 females in Hertfordshire, UK. Dietary information was obtained by food frequency questionnaire and dietary patterns were identified using principal components analysis. Using regression analysis, after controlling for confounders, a "prudent" pattern (high consumption of fruit, vegetables, oily fish and wholemeal cereals) was positively associated with forced expiratory volume in 1 s (FEV(1)) (trend p-value <0.001 in males, 0.008 in females) (difference in FEV(1) between top and bottom quintiles of pattern score, 0.18 L (95% CI 0.08-0.28 L) in males, 0.08 L (95% CI 0.00-0.16 L) in females). This pattern was also positively associated with forced vital capacity (FVC) in both sexes. Males with a higher "prudent" pattern score had a higher FEV(1)/FVC (trend p-value 0.002) and a lower prevalence of COPD (odds ratio comparing top versus bottom quintile 0.46, 95% CI 0.26-0.81; trend p-value 0.012). Associations in males were stronger in smokers than nonsmokers (interaction p-value for FEV(1)/FVC 0.002). A "prudent" dietary pattern may protect against impaired lung function and COPD, especially in male smokers.