Hayley J. Denison

Prevalence of sarcopenia in community-dwelling older people in the UK using the European Working Group on Sarcopenia in Older People (EWGSOP) definition: findings from the Hertfordshire Cohort Study (HCS)

Introduction: sarcopenia is associated with adverse health outcomes. The aim of this study was to describe the prevalence of sarcopenia in community-dwelling older people in the UK using the European Working Group on Sarcopenia in Older People (EWGSOP) consensus definition. Methods: we applied the EWGSOP definition to 103 community-dwelling men participating in the Hertfordshire Sarcopenia Study (HSS) using both the lowest third of dual-energy X-ray absorptiometry (DXA) lean mass (LM) and the lowest third of skin-fold-based fat-free mass (FFM) as markers of low muscle mass. We also used the FFM approach among 765 male and 1,022 female participants in the Hertfordshire Cohort Study (HCS). Body size, physical performance and self-reported health were compared in participants with and without sarcopenia. Results: the prevalence of sarcopenia in HSS men (mean age 73 years) was 6.8% and 7.8% when using the lowest third of DXA LM and FFM, respectively. DXA LM and FFM were highly correlated (0.91, P < 0.001). The prevalence of sarcopenia among the HCS men and women (mean age 67 years) was 4.6% and 7.9%, respectively. HSS and HCS participants with sarcopenia were shorter, weighed less and had worse physical performance. HCS men and women with sarcopenia had poorer self-reported general health and physical functioning scores. Conclusions: this is one of the first studies to describe the prevalence of sarcopenia in UK community-dwelling older people. The EWGSOP consensus definition was of practical use for sarcopenia case finding. The next step is to use this consensus definition in other ageing cohorts and among older people in a range of health-care settings.

Prevention and optimal management of sarcopenia: a review of combined exercise and nutrition interventions to improve muscle outcomes in older people.

The growing recognition of sarcopenia, the age-related loss of skeletal muscle mass and function, has highlighted the need to understand more about its etiology. Declines in muscle mass and strength are expected aspects of aging, but there is significant variability between individuals in rates of loss. Although some of these differences can be explained by fixed factors, such as sex, much of the remaining variation is unexplained. This has led to increasing interest in the influence of adult lifestyle, particularly in the effects of modifiable factors such as physical activity and diet, and in identifying intervention opportunities both to prevent and manage sarcopenia. A number of trials have examined the separate effects of increased exercise or dietary supplementation on muscle mass and physical performance of older adults, but less is known about the extent to which benefits of exercise training could be enhanced when these interventions are combined. In a comprehensive review of the literature, we consider 17 studies of older adults (≥65 years) in which combined nutrition and exercise interventions were used to increase muscle strength and/or mass, and achieve improvements in physical performance. The studies were diverse in terms of the participants included (nutritional status, degree of physical frailty), supplementation strategies (differences in nutrients, doses), exercise training (type, frequency), as well as design (duration, setting). The main message is that enhanced benefits of exercise training, when combined with dietary supplementation, have been shown in some trials – indicating potential for future interventions, but that existing evidence is inconsistent. Further studies are needed, particularly of exercise training combined with dietary strategies that increase intakes of a range of nutrients, as well as bioactive non-nutrients, to provide the evidence on which public health and clinical recommendations can be based.

Birth weight and muscle strength: a systematic review and meta-analysis.

ObjectiveLower muscle strength is associated with a range of adverse health outcomes in later life. The variation in muscle strength between individuals is only partly accounted for by factors in adult life such as body size and physical activity. The aim of this review was to assess the strength of the association between intrauterine development (indicated by birth weight) and subsequent muscle strength.DesignSystematic review and meta-analysis of studies that assessed the association between birth weight and subsequent muscle strength.ResultsNineteen studies met inclusion criteria with 17 studies showing that higher birth weight was associated with greater muscle strength. Grip strength was used as a single measure of muscle strength in 15 studies. Metaanalysis (13 studies, 20 481 participants, mean ages 9.3 to 67.5) showed a 0.86 kg (95% CI 0.58, 1.15) increase in muscle strength per additional kilogram of birth weight, after adjustment for age, gender and height at the time of strength measurement.ConclusionThis review has found consistent evidence of a positive association between birth weight and muscle strength which is maintained across the lifecourse. Future work will be needed to elucidate the biological mechanisms underlying this association, but it suggests the potential benefit of an early intervention to help people maintain muscle strength in later life.

Clinical risk factors, bone density and fall history in the prediction of incident fracture among men and women

The FRAX(tr) algorithm uses clinical risk factors (CRF) and bone mineral density (BMD) to predict fracture risk but does not include falls history in the calculation. Using results from the Hertfordshire Cohort Study, we examined the relative contributions of CRFs, BMD and falls history to fracture prediction. We studied 2299 participants at a baseline clinic that included completion of a health questionnaire and anthropometric data. A mean of 5.5years later (range 2.9-8.8years) subjects completed a postal questionnaire detailing fall and fracture history. In a subset of 368 men and 407 women, bone densitometry was performed using a Hologic QDR 4500 instrument. There was a significantly increased risk of fracture in men and women with a previous fracture. A one standard deviation drop in femoral neck BMD was associated with a hazards ratio (HR) of incident fracture (adjusted for CRFs) of 1.92 (1.04-3.54) and 1.77 (1.16-2.71) in men and women respectively. A history of any fall since the age of 45years resulted in an unadjusted HR of fracture of 7.31 (3.78-14.14) and 8.56 (4.85-15.13) in men and women respectively. In a ROC curve analysis, the predictive capacity progressively increased as BMD and previous falls were added into an initial model using CRFs alone. Falls history is a further independent risk factor for fracture. Falls risk should be taken into consideration when assessing whether or not to commence medication for osteoporosis and should also alert the physician to the opportunity to target falls risk directly.

Peripheral quantitative computed tomography measures are associated with adult fracture risk: the Hertfordshire Cohort Study.

Peripheral quantitative computed tomography (pQCT) captures novel aspects of bone geometry that may contribute to fracture risk and offers the ability to measure both volumetric bone mineral density (vBMD) and a separation of trabecular and cortical compartments of bone, but longitudinal data relating measures obtained from this technique to incident fractures are lacking. Here we report an analysis from the Hertfordshire Cohort Study, where we were able to study associations between measures obtained from pQCT and DXA in 182 men and 202 women aged 60-75 years at baseline with incident fractures over 6 years later. Among women, radial cortical thickness (HR 1.72, 95% CI 1.16, 2.54, p=0.007) and cortical area (HR 1.91, 95% CI 1.27, 2.85, p=0.002) at the 66% slice were both associated with incident fractures; these results remained significant after adjustment for confounders (age, BMI, social class, cigarette smoking and alcohol consumption, physical activity, dietary calcium, HRT and years since menopause). Further adjustment for aBMD made a little difference to the results. At the tibia, cortical area (HR 1.58, 95% CI 1.10, 2.28, p=0.01), thickness (HR 1.49, 95% CI 1.08, 2.07, p=0.02) and density (HR 1.64, 95% CI 1.18, 2.26, p=0.003) at the 38% site were all associated with incident fractures with the cortical area and density relationships remaining robust to adjustment for the confounders listed above. Further adjustment for aBMD at this site did lead to attenuation of relationships. Among men, tibial stress-strain index (SSI) was predictive of incident fractures (HR 2.30, 95% CI 1.28, 4.13, p=0.005). Adjustment for confounding variables and aBMD did not render this association non-significant. In conclusion, we have demonstrated relationships between measures of bone size, density and strength obtained by pQCT and incident fracture. These relationships were attenuated but in some cases remained significant after adjustment for BMD measures obtained by DXA, suggesting that some additional information may be conferred by this assessment.

Patterns of dietary supplement use among older men and women in the UK: Findings from the Hertfordshire Cohort Study

ObjectivesTo determine patterns of supplement use in a UK community-dwelling older population, and to investigate the extent to which supplement user groups differ, in terms of their sociodemographic and lifestyle characteristics, diet and morbidity.DesignCross-sectional cohort study.SettingHome interview and clinic visit. Participants: 3217 Hertfordshire Cohort Study participants, aged 59 to 73.MeasurementsInformation was obtained on the participant’s social and medical history by a trained research nurse. Diet over the preceding 3 months was assessed by Food Frequency Questionnaire; compliance with ‘healthy’ eating recommendations was defined using individual scores for a ‘prudent’ dietary pattern, identified using principal components analysis. Details of all dietary supplements taken in the preceding 3 months were recorded. Individual supplements were allocated to one of 10 types based on their nutrient composition. Cluster analysis was used to define groups of supplement users.Results45.4% of men and 57.5% of women reported taking at least one dietary supplement in the previous 3 month period. There were 5 distinct clusters of supplement users; these were common to men and women. They were labelled according to the principal supplement taken; oils, glucosamine, single vitamins, vitamins and minerals, and herbal products. These groups differed in their social class and prudent diet score, but few other characteristics. With the exception of a difference in diagnosis of diabetes among the women, there were no differences in morbidity between the supplement groups in either men or women.ConclusionsDietary supplement use is high in this population. There are distinct patterns of supplement use, which are related to sociodemographic and lifestyle characteristics including diet, though there were few clear differences in morbidity.

Effects of Aerobic Exercise on Muscle Strength and Physical Performance in Community‐dwelling Older People from the Hertfordshire Cohort Study: A Randomized Controlled Trial

To the Editor: There is considerable interest in the role of physical activity interventions to address the age-related loss of skeletal muscle mass. Resistance exercise is consistently associated with improvement in muscle strength and physical performance (PP) in older adults but the influence of aerobic exercise on these outcomes is less clear. Studies of the influence of aerobic exercise on muscle have typically taken place among specific patient populations and less so in older people. We studied the effects of a fully supervised 12 week aerobic exercise intervention on muscle strength and PP among the community-dwelling healthy older men and women who participated in the Hertfordshire Physical Activity Intervention Trial (HPAT),1 a sub-study of the Hertfordshire Cohort Study.2

How to get started with a systematic review in epidemiology: an introductory guide for early career researchers

BackgroundSystematic review is a powerful research tool which aims to identify and synthesize all evidence relevant to a research question. The approach taken is much like that used in a scientific experiment, with high priority given to the transparency and reproducibility of the methods used and to handling all evidence in a consistent manner.Early career researchers may find themselves in a position where they decide to undertake a systematic review, for example it may form part or all of a PhD thesis. Those with no prior experience of systematic review may need considerable support and direction getting started with such a project. Here we set out in simple terms how to get started with a systematic review.DiscussionAdvice is given on matters such as developing a review protocol, searching using databases and other methods, data extraction, risk of bias assessment and data synthesis including meta-analysis. Signposts to further information and useful resources are also given.ConclusionA well-conducted systematic review benefits the scientific field by providing a summary of existing evidence and highlighting unanswered questions. For the individual, undertaking a systematic review is also a great opportunity to improve skills in critical appraisal and in synthesising evidence.

Barriers to sexually transmitted infection testing in New Zealand: a qualitative study

Objective: To investigate the barriers that prevent or delay people seeking a sexually transmitted infection (STI) test.

Academic careers: what do early career researchers think?

ARE YOUNG RESEARCHERS GETTING A FAIR DEAL? Early career researchers (ECRs) are often anecdotally described as facing major challenges. These challenges reportedly include lack of job security, too few opportunities to carve out their own interests, fighting to survive in competitive institutions and being perceived as resources rather than as people. These issues have attracted increasing attention in scientific circles and now also in the media. In response to these concerns, the SSM ECR Subcommittee conducted an ECR members’ survey in early 2015 to obtain views on a range of issues. We had 65 responses (response rate 50.7%) of whom approximately three-quarters were female, and a third were based in London. Responses clustered around three main themes: job instability, limited opportunities to develop an academic career and lack of mentoring.