Adequacy of nutritional intake among older men living in Sydney, Australia: findings from the Concord Health and Ageing in Men Project (CHAMP)

Previous research shows that older men tend to have lower nutritional intakes and higher risk of under-nutrition compared with younger men. The objectives of this study were to describe energy and nutrient intakes, assess nutritional risk and investigate factors associated with poor intake of energy and key nutrients in community-dwelling men aged 75 years participating in the Concord Health and Ageing in Men Project - a longitudinal cohort study on older men in Sydney, Australia. A total of 794 men (mean age 81.4 years) had a detailed diet history interview, which was carried out by a dietitian. Dietary adequacy was assessed by comparing median intakes with nutrient reference values (NRV): estimated average requirement, adequate intake or upper level of intake. Attainment of NRV of total energy and key nutrients in older age (protein, Fe, Zn, riboflavin, Ca and vitamin D) was incorporated into a "key nutrients" variable dichotomised as "good" (5) or "poor" (4). Using logistic regression modelling, we examined associations between key nutrients with factors known to affect food intake. Median energy intake was 8728 kJ (P5=5762 kJ, P95=12 303 kJ), and mean BMI was 27.7 (sd 4.0) kg/m(2). Men met their NRV for most nutrients. However, only 1 % of men met their NRV for vitamin D, only 19 % for Ca, only 30 % for K and only 33 % for dietary fibre. Multivariate logistic regression analysis showed that only country of birth was significantly associated with poor nutritional intake. Dietary intakes were adequate for most nutrients; however, only half of the participants met the NRV of 5 key nutrients

Frailty and use of health and community services by community-dwelling older men: the Concord Health and Ageing in Men Project

Background: frailty is a concept used to describe older people at high risk of adverse outcomes, including falls, functional decline, hospital or nursing home admission and death. The associations between frailty and use of specific health and community services have not been investigated. Methods: the cross-sectional relationship between frailty and use of several health and community services in the last 12 months was investigated in 1,674 community-dwelling men aged 70 or older in the Concord Health and Ageing in Men study, a population-based study conducted in Sydney, Australia. Frailty was assessed using a modified version of the Cardiovascular Health Study criteria. Results: overall, 158 (9.4%) subjects were frail, 679 (40.6%) were intermediate (pre-frail) and 837 (50.0%) were robust. Frailty was associated with use of health and community services in the last 12 months, including consulting a doctor, visiting or being visited by a nurse or a physiotherapist, using help with meals or household duties and spending at least one night in a hospital or nursing home. Frail men without disability in activities of daily living were twice more likely to have seen a doctor in the previous 2 weeks than robust men (adjusted odds ratio 2.04, 95% confidence interval 1.21-3.44), independent of age, comorbidity and socio-economic status. Conclusion: frailty is strongly associated with use of health and community services in community-dwelling older men. The high level of use of medical services suggests that doctors and nurses could play a key role in implementation of preventive intervention

Too Much Medicine in older people? Deprescribing through Shared Decision Making

Too much medicine is an increasingly recognised problem,1 2 and one manifestation is inappropriate polypharmacy in older people. Polypharmacy is usually defined as taking more than five regular prescribed medicines.3 It can be appropriate (when potential benefits outweigh potential harms)4 but increases the risk of older people experiencing adverse drug reactions, impaired physical and cognitive function, and hospital admission.5 6 7 There is limited evidence to inform polypharmacy in older people, especially those with multimorbidity, cognitive impairment, or frailty.8 Systematic reviews of medication withdrawal trials (deprescribing) show that reducing specific classes of medicines may decrease adverse events and improve quality of life.9 10 11 Two recent reviews of the literature on deprescribing stressed the importance of patient involvement and shared decision making.12 13 Patients and clinicians typically overestimate the benefits of treatments and underestimate their harms.14 When they engage in shared decision making they become better informed about potential outcomes and as a result patients tend to choose more conservative options (eg, fewer medicines), facilitating deprescribing.15 However, shared decision making in this context is not easy, and there is little guidance on how to do it.16 We draw together evidence from the psychology, communication, and decision making literature (see appendix on thebmj.com). For each step of the shared decision making process we describe the unique tasks required for deprescribing decisions; identify challenges for older adults, their companions, and clinicians (figure); give practical advice on how challenges may be overcome; highlight where more work is needed; and identify priorities for future research (table). Key messages Deprescribing is a process of planned and supervised tapering or ceasing of inappropriate medicines Shared decision making should be an integral part of the deprescribing process Many factors affect this process, including trust in clinicians’ advice, contradictory patient attitudes about medication, cognitive biases that lead to a preference for the status quo and positive information, and information processing difficulties There is uncertainty about the effect of risk communication and preference elicitation tools in older people Older people’s preferences for discussing life expectancy and quality of life vary widely, but even those who wish to delegate their decisions still appreciate discussion of optionsJJ is supported by a National Health and Medical Research Council (NHMRC) early career fellowship (1037028) and KM is supported by an NHMRC career development fellowship (1029241

Polarization-dependent optomechanics mediated by chiral microresonators.

Chirality is one of the most prominent and intriguing aspects of nature, from spiral galaxies down to aminoacids. Despite the wide range of living and non-living, natural and artificial chiral systems at different scales, the origin of chirality-induced phenomena is often puzzling. Here we assess the onset of chiral optomechanics, exploiting the control of the interaction between chiral entities. We perform an experimental and theoretical investigation of the simultaneous optical trapping and rotation of spherulite-like chiral microparticles. Due to their shell structure (Bragg dielectric resonator), the microparticles function as omnidirectional chiral mirrors yielding highly polarization-dependent optomechanical effects. The coupling of linear and angular momentum, mediated by the optical polarization and the microparticles chiral reflectance, allows for fine tuning of chirality-induced optical forces and torques. This offers tools for optomechanics, optical sorting and sensing and optofluidics

Repeated, Selection-Driven Genome Reduction of Accessory Genes in Experimental Populations

Genome reduction has been observed in many bacterial lineages that have adapted to specialized environments. The extreme genome degradation seen for obligate pathogens and symbionts appears to be dominated by genetic drift. In contrast, for free-living organisms with reduced genomes, the dominant force is proposed to be direct selection for smaller, streamlined genomes. Most variation in gene content for these free-living species is of “accessory” genes, which are commonly gained as large chromosomal islands that are adaptive for specialized traits such as pathogenicity. It is generally unclear, however, whether the process of accessory gene loss is largely driven by drift or selection. Here we demonstrate that selection for gene loss, and not a shortened genome, per se, drove massive, rapid reduction of accessory genes. In just 1,500 generations of experimental evolution, 80% of populations of Methylobacterium extorquens AM1 experienced nearly parallel deletions removing up to 10% of the genome from a megaplasmid present in this strain. The absence of these deletion events in a mutation accumulation experiment suggested that selection, rather than drift, has dominated the process. Reconstructing these deletions confirmed that they were beneficial in their selective regimes, but led to decreased performance in alternative environments. These results indicate that selection can be crucial in eliminating unnecessary genes during the early stages of adaptation to a specialized environment

The Repeatability of Adaptive Radiation During Long-Term Experimental Evolution of Escherichia coli in a Multiple Nutrient Environment

Adaptive radiations occur when a species diversifies into different ecological specialists due to competition for resources and trade-offs associated with the specialization. The evolutionary outcome of an instance of adaptive radiation cannot generally be predicted because chance (stochastic events) and necessity (deterministic events) contribute to the evolution of diversity. With increasing contributions of chance, the degree of parallelism among different instances of adaptive radiations and the predictability of an outcome will decrease. To assess the relative contributions of chance and necessity during adaptive radiation, we performed a selection experiment by evolving twelve independent microcosms of Escherichia coli for 1000 generations in an environment that contained two distinct resources. Specialization to either of these resources involves strong trade-offs in the ability to use the other resource. After selection, we measured three phenotypic traits: 1) fitness, 2) mean colony size, and 3) colony size diversity. We used fitness relative to the ancestor as a measure of adaptation to the selective environment; changes in colony size as a measure of the evolution of new resource specialists because colony size has been shown to correlate with resource specialization; and colony size diversity as a measure of the evolved ecological diversity. Resource competition led to the rapid evolution of phenotypic diversity within microcosms. Measurements of fitness, colony size, and colony size diversity within and among microcosms showed that the repeatability of adaptive radiation was high, despite the evolution of genetic variation within microcosms. Consistent with the observation of parallel evolution, we show that the relative contributions of chance are far smaller and less important than effects due to adaptation for the traits investigated. The two-resource environment imposed similar selection pressures in independent populations and promoted parallel phenotypic adaptive radiations in all independently evolved microcosms

Optimal Resting-Growth Strategies of Microbial Populations in Fluctuating Environments

Bacteria spend most of their lifetime in non-growing states which allow them to survive extended periods of stress and starvation. When environments improve, they must quickly resume growth to maximize their share of limited nutrients. Cells with higher stress resistance often survive longer stress durations at the cost of needing more time to resume growth, a strong disadvantage in competitive environments. Here we analyze the basis of optimal strategies that microorganisms can use to cope with this tradeoff. We explicitly show that the prototypical inverse relation between stress resistance and growth rate can explain much of the different types of behavior observed in stressed microbial populations. Using analytical mathematical methods, we determine the environmental parameters that decide whether cells should remain vegetative upon stress exposure, downregulate their metabolism to an intermediate optimum level, or become dormant. We find that cell-cell variability, or intercellular noise, is consistently beneficial in the presence of extreme environmental fluctuations, and that it provides an efficient population-level mechanism for adaption in a deteriorating environment. Our results reveal key novel aspects of responsive phenotype switching and its role as an adaptive strategy in changing environments